NE9271 Supervisory Control and Data Acquisition System (SCADA)

Transcription

1 NE9271 Supervisory Control and Data Acquisition System (SCADA) TQ Education and Training Ltd 2006 No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording or any information storage and retrieval system without the express permission of TQ Education and Training Limited. All due care has been taken to ensure that the contents of this manual are accurate and up to date. However, if any errors are discovered please inform TQ so the problem may be rectified. A Packing Contents List is supplied with the equipment. Carefully check the contents of the package(s) against the list. If any items are missing or damaged, contact your local TQ agent or TQ immediately. AB/DB/0106

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3 Section Contents Page 1 Introduction 1 SCADA Systems 1 General Requirements of SCADA Systems 1 SCADA Components 2 The MiCOM S10 Protection Based Substation Control System 4 The MiCOM S10 Software 6 The S10 Graphical and Control Interface 6 Use of the S10 with the PSS 6 Outline of the Manual 7 2 Entry to the SCADA System 9 Entry to the S10 Program: The Site Screen 9 General Screen Organisation 10 Logging-on to the MiCOM application 11 The Overview Screen 13 The Bay Screen 14 System Screens 15 Navigating between System and Overview Screens 17 3 Remote Control of the Power System Simulator 19 The Control Panel 19 4 Reading Fault and Measured Data 21 Measured Values of System Quantities 21 Measurements from System Screens 22 Sequence of Events Recording (SOE) and Alarms 31 The Software Tools Tab 35 5 Experiment Screens 39 Introduction 39 Features of Each Screen 40 Experiment 2: Generator Control - Vee Curves 41 Experiment 3: Generator Control - P Q Chart 43 Experiment 4: System Voltage Regulation - P-Q Flow 45 Experiment 5: System Voltage Regulation - Constant PF Load 47 Experiment 6b: Three-phase Transformers - Unequal Taps 49 Experiment 6c: Three-Phase Transformers - Unequal Impedances 51 Experiment 6d: Three-Phase Transformers - Unbalanced Load. 53 Experiment 7: Load Flow Study - Three Bus System 55 Experiment 8a: Symmetrical Faults - Unloaded System 57 Experiment 8b: Symmetrical Faults - Loaded Systems 59 Experiment 8c: Symmetrical Fault - IM Contribution 61 Experiment 8d: Symmetrical Faults - 4 Bus System 63 Experiment 9a: Unsymmetrical Faults - I2 Measurement 65 Experiment 9b: Unsymmetrical Faults - Trans Line Faults 67 Experiment 9c: Unsymmetrical Faults - TX Terminated Line 69 i

4 Experiment 9d: Unsymmetrical Faults - Double End Feed 71 Experiment 12: OC Protection - Relay Grading 73 Experiment 13: Symmetrical Faults - Auto-reclose. 75 Experiment 14: Symmetrical Faults - Inst. High Set 77 Experiment 15: Over Current Protection - Back Trip 79 Experiment 16: Over Current Protection - Directional Control (and TX) 81 Experiment 17: Distance Protection 83 Experiment 18: Grid Transformer Protection and REF Protection 85 Experiment 19: Busbar Protection 89 Experiment 20: Generator Protection 91 Second Generator Experiments 93 Experiment 23: Generators in Parallel, Connected to the Grid 95 Experiment 24: Second Generator Automatic Control - VAr Control 97 Experiment 25: Second Generator Automatic Control - Power Factor (Cosφ) Control 99 Experiment 26: Second Generator as an Embedded Generator - P & Q Flow in a Distribution System 101 APPENDIX 1 Alarms and Sequence of Events (SOE) 103 APPENDIX 2 Access Rights 105 APPENDIX 3 Connection Diagrams 107 Experiments 2 and 3: Generator Control 107 Experiments 4 and 5: System Voltage Regulation 108 Experiment 6: Three Phase Transformers - Parts B, C and D 109 Experiment 7: Load Flow 110 Experiment 8a: Symmetrical Faults - Unloaded System 111 Experiment 8b: Symmetrical Faults - Loaded System 112 Experiment 8c: Symmetrical Faults - Induction Motor Contribution 113 Experiment 8d: Symmetrical Faults - Four Bus System 114 Experiment 9a and 9b: Unsymmetrical Faults - I2 Measurement and Transmission Line Faults 115 Experiment 9c: Unsymmetrical Faults - Transformer Terminated Line 116 Experiment 9d: Unsymmetrical Faults - Double End Feed 117 Experiments 12, 14 and 15: Overcurrent Protection - Relay Grading, High Set and Back Trip 118 Experiment 13: Overcurrent Protection - Auto Reclose 119 Experiment 16: Overcurrent Protection - Directional Control 120 Experiment 17: Distance Protection 121 Experiment 18: Grid Transformer Protection 122 Experiment 19: Busbar Protection 123 Experiment 20: Generator Protection 124 Experiment 23: Generators in Parallel, Connected to the Grid 125 Experiment 24: Second Generator Automatic Control - VAr Control and Experiment 25: Second Generator Automatic Control - Power Factor (Cosf) Control 126 Experiment 26: Second Generator as an Embedded Generator - P & Q Flow in a Distribution System 127 APPENDIX 4 Numerical Addresses for Relays and Meters 129 ii

5 SECTION 1.0 Introduction 1.1 SCADA Systems Disturbances and persistent faults on power systems may lead to the tripping and isolation of plant. If tripping occurs, then the operation of the power system has to be reassessed and corrective control actions taken so that all consumers have a secure supply, at least cost. The real-time assessment and control of an integrated power system is made possible by an Energy Management System (EMS). Assessment of plant condition and system loading requires the collection of system data from relays and plant controllers at local substations. Remote terminal units (RTUs) are used to collect and transmit data to Control Centres at local level, area level or a higher, central coordinating control. The collected data from relays and RTUs needs to be presented at Control Centres in a visual and meaningful way to enable system control and maintenance to be carried out. This is achieved by a Supervisory Control and Data Acquisition (SCADA) system. The SCADA displays the information on a PC screen; usually by coloured one-line mimic diagrams. The PC is referred to as the master station. At the Central Control level, the SCADA system feeds into an Alarm Management System and the EMS. An Alarm Management subsystem processes the SCADA information to give warning of system abnormality not detected at local level. The EMS processes SCADA information and combines the data produced with load flow data to determine the state of the system. Such a computational procedure, using mathematical methods, is called state estimation. 1.2 General Requirements of SCADA Systems A SCADA System typically provides the following functions: comprehensive monitoring of primary and secondary plant secure control of primary plant supervision of secondary plant operator controlled display of non-scada data alarm management event logging sequence of events recording trend recording All functions must be provided with a high level of security and reliability. The control system itself must be highly self-monitoring and problems brought immediately to the operator s attention. Operator access must also be protected by a security system. In addition, certain performance standards are required, for both data acquisition and the user interface. For example, time recording of events to one millisecond resolution is now possible. Whilst user interface performance is less critical, operators expect that their actions will result in display delays measured in only a few seconds: for example, from the execution of a circuit breaker control, to the change of indications on the display. Page 1

6 1.3 SCADA Components A SCADA system has three essential components to provide the functions listed above. 1) Relays, or Intelligent Electronic Devices (IEDs) 2) A Communication Interface 3) A User Interface 1) Relays In addition to their basic protection settings and functions relays must posses a comprehensive database of: Plant status indication (e.g., cb open/closed) Direct measurement (V, I, f) Derived Measurements (P,VA, Energy, Peak and Average Values) Event records Fault records Self-test status The relays also require auxiliary inputs to monitor plant and outputs to control plant devices. Modern numeric (or software-based) relays are capable of providing a majority of these functions. In some cases it may be necessary to have additional basic relays or RTUs to provide primary plant monitoring and control. Modern protection and control relays used in SCADA systems are provided with serial communication ports. These ports enable relays to be linked to a suitable master station and their databases interrogated to extract the data. Similarly commands can be sent from the master station to the relays in order to control plant devices. 2) Communications Interface The interface consists of two parts: a physical communications link between relays and master station, and a software interface within the master station. Only the MiCOM S10 communications system is described here. The collective interface should have the ability to: Handle multiple relays Extract data from the relay databases measurements, event records, Display disturbance records and settings Send data to the relays control commands, setting changes Implement scanning strategies cyclical polling, on-demand, on-event Handle communications failures re-tries, failure alarms 3) User Interfaces The PC and compatible technology are now natural and acceptable choices for most user interface, master station systems. Many options are available, both in hardware and software. In terms of processing power, Page 2

7 PCs at the upper end of the available range are preferred and are capable of providing the high performance that is preferred of such systems. Software is also readily available for SCADA applications in the form of standard Windows compatible packages that offer general capability in terms of: Database design Mimic diagram design Alarm and event management facilities Trending (real time and historical) Animation and user programmed functions Monitoring and diagnostics The DDE Software Interface A special program in the PC, designed to handle the communications protocol of the relays, can provide many of the functions listed above. Such a program needs to be highly user-configurable in order to provide selective handling of relay data, alternative scanning strategies and different arrangements of relays in specific applications. The program must also transfer the relay data to and from Windows applications, not only the SCADA user interface, but also other useful software such as spreadsheets and database managers. The Windows environment provides a mechanism, referred to as Dynamic Data Exchange (DDE), which can be used for this function. See Figure 1. User SCADA Application DDE Server DDE Server Multiport System Modbus Driver MBUSDRV Courier Driver Micom DDE Windows 2000 RS232 Port RS232 Port RS232/485 Modbus DH96 Kitz K Bus Courier Device M230 Courier Device M230 Courier Device Figure 1 Communication Between User, PC Master Station and Relays (Courier Devices) Page 3

8 1.4 The MiCOM S10 Protection Based Substation Control System The MiCOM S10 is a distributed system that provides a link between one or more PCs with user interfaces and IEDs, such as protective relays. The MiCOM S10 applies to MiCOM P range and the older K range relays. The system uses a communication protocol known as Courier. Courier is a communication language developed specifically for protective relays. It allows a master station to transfer data and commands to and from multiple relays over a communication network without affecting the ability of the relays to perform their protective functions. The Courier protocol is master/slave in which each relay is a slave with an individual address. Each relay is directly addressable over the bus to allow communication with any selected relay. The communication process is continuous, involving all of the relays in sequence. The protocol includes extensive error checking routines to ensure the system remains reliable and secure. The rear ports of the relays provide K-Bus/RS485 serial data transmission and are intended for use with a permanently wired connection to a remote control centre. The relays are interconnected via a shielded, twisted-pair copper cable known as a K Bus. Up to thirty two relays may be connected in parallel across a single bus, or spur, of maximum overall length 1000 m. The K Bus is connected through a protocol converter known as KITZ, either directly or via a modem, to the RS232 port of a PC. The KITZ provides signals over the communications bus that are RS485 based and are transmitted at 64K bits per second. The K-Bus and KITZ connections are shown in Figure 2. The KITZ converters are small boxes located adjacent the remote PC. The interface to the remote PC and converters is located in the side panel on the right-hand side of the Simulator. An alternative to the Courier protocol is Modbus: a similar master/slave communication protocol for network control. In the Simulator, Modbus is used mostly for interrogating the M230 Communicating Measurement Systems. Communication Settings Having made the physical connection to the relay, the relay s communication settings must be configured. This is achieved by first checking that the Comms settings cell in the Configuration column of the relay Menu is set to visible, before moving to the communications column. Only two settings apply to the rear port using Courier, the relay s address and the inactivity timer. The first cell down the Communications column should be set to Protocol: Courier. The next cell down the column controls the address of the relay. Each relay must have a unique address so that messages from the master control station are accepted by one relay only. The next cell down controls the inactivity timer. The inactivity timer controls how long the relay will wait without receiving any messages on the rear port before it reverts to its default state, including revoking any password access that was enabled. For the rear port this can be set between 1 and 30 minutes. Refer to the relevant Technical Manual for more detailed instruction. Page 4

9 Copyright Permission from Areva Figure 2 Remote Communication Connection Arrangements Page 5

10 1.5 The MiCOM S10 Software The S10 Software has three main elements: 1) The Operating System (Windows 2000). 2) The S10 application software A main element of the software is the configurator. This software helps configure all aspects of the application (substations, bays, relays, for example). It provides information and a framework for the presentational, on-screen software and configures aspects of communication with the relays. 2) The Wonderware In Touch Software This software provides integrated on screen views of the electrical systems, including controls and information resources. Graphical representations on screen are enabled by a window editor called Window Maker 1.6 The S10 Graphical and Control Interface The S10 Software is designed for on-screen supervision and control of power system substations. In general terms, it has four viewing levels: The Site View (or General Overview) This screen has name-buttons for accessing a general view of each of the constituent Substations within the Site (e.g. at different voltage levels). The Substation View These screens show a graphical overview of each Substation. The Electrical Bay Clicking on the name-buttons in each Substation can access a graphical view of each Bay. Relay Details Clicking on the relay icon buttons can access a view of each relay in a Bay. 1.7 Use of the S10 with the PSS The S10 software is used on the PSS for carrying out and controlling remotely, individual experiments. The experiments are as numbered and described in the PSS Manual. The structure and viewing levels of the S10 have been configured so that each experiment circuit and screen is a separate, named 'Substation'. They appear therefore as a list on the overall Site view. Individual one-line mimic diagrams for each experiment are obtained by clicking on the name of the Experiment. Each Experiment Screen has control buttons for accessing relays and meters as well as buttons for load and generator control and fault application. The user cannot reconfigure the mimic diagram or controls for the Experimental Screens. Page 6

11 1.8 Outline of the Manual The function of this Manual is to provide a description of the on-screen facilities provided by the S10 software and procedures for carrying out set Experiments on the PSS. Both this Manual and the PSS Manual should be used when carrying out Experiments. The User Guide for the S10, provided by Areva, may also be referred to for a more general description of on-screen facilities. Section 2 describes the general content and organisation of the S10 screens including how to access them and to move between them. Section 3 describes several control screens developed specifically for use with the TQ PSS. Section 4 describes methods available with the S10 for extracting measurements and fault data from the relays. Section 5 is the largest section, providing step-by-step procedures for carrying out with the S10 the experiments described in the PSS Manual. The identification numbers of the experiments are those used in the PSS. These are suggested procedures. It is expected that staff in charge of the PSS may wish to vary the procedure or alter the contents of the experiments. For completeness and clarity, the connection diagrams for the experiments given in the PSS Manual are also included in Appendix 3 of this manual. Page 7

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13 SECTION 2.0 Entry to the SCADA System This Section describes initial entry to the NE9271 SCADA System and its organisation and Screens. 2.1 Entry to the S10 Program: The Site Screen The PC supplied as part of the NE9271 SCADA automatically starts the SCADA software when you log on to the Windows 2000 logon dialogue box (see Figure 3). Note: The PC is set up as a dedicated SCADA machine, you cannot access other Windows programmes. You cannot minimize or resize any of the S10 screens. Figure 3 Windows 2000 Logon Dialogue Box The user name should already be set to micomuser. You must then enter the password micomuser into the password text box and then press OK. The computer will then load its operating system and start the Micom S10 software. The opening screen (shown in Figure 4), is a temporary screen indicating progress in loading the application software. The Site Screen (or General Overview Screen) appears when the application software has been loaded (see Figure 5). The Site Screen lists the individual 'Substations', or Experiments, in a drop-down menu opened by clicking on the down arrow. Figure 4 Opening Screen Page 9

14 Figure 5 Site Screen An initial Overview Screen heads the list. This screen is followed by a list of Experiment Screens. Each of these screens gives a circuit diagram and controls for an experiment described in the manual for the Power System Simulator, the NE9270. These experiment screens will be discussed in a later section. 2.2 General Screen Organisation MiCOM S10 screens are divided into three main parts: 1) The top bar gives information on alarms and events. 2) The central part of the screen shows circuits or information according to the activated function: electrical single line, system view, measurements, alarms etc. 3) The bottom bar provides navigation between the different screens. Top Bar The top bar displays the last alarms on the system. It is always visible. The alarm indicator lamp indicates the status of the alarm: A steady green light indicates a healthy status. A flashing red light indicates an unacknowledged alarm. Clicking on the alarm indicator cancels the audible alarm. An audible alarm may be configured in order to indicate a new alarm. Depending on the access level, the user can acknowledge the audible alarm by clicking on the alarm indicator lamp when the alarm is present. Note: The alarm is present each time you start the software - this is normal. Page 10

15 Bottom Bar The bottom bar displays several tabs allowing the user to change the screen view. It is always visible. The tabs provide access to the following Screens or information: Overview: Access to the main site overview: it can be an electrical view or a view with buttons to access all the individual substation views. Alarms: Access to full alarm list and alarm management. System: Access to the system overview, displaying graphical representation of the MiCOM S10 system elements status (PC, relays, LEDs ) Trends: Access to the variation with time of such quantities as current, voltage, active power, reactive power and frequency. SOE: Access to the Sequence Of Events Recorder. Software: Access to Disturbance Analysis software (Win Analyse) Histogram: Access to displays of historical trends of measured quantities. Notes: Access to text notes (to create, read, and update text files). 2.3 Logging-on to the MiCOM application Before you can operate the Power System Simulator, you must be logged on. At the right-hand end of the bottom bar is the User Log On window to enter the operator s name and password (see Figures 6 and 7). A turn-on key-button indicates a logged on user with name and access level. Figure 6 Logged Off Figure 7 Logged On To log-on as an operator The system provides security of operation using a password-protected log-on facility. Before logging the access level is 0 (viewing only) (see Figure 6). The System Administrator defines the access level for each operator. Access levels define the operational functions available to an operator. Appendix 2 gives a Table relating Function to Access level. To access the log on window, click on the key button. The log on window appears. It has two buttons: User and Password (see Figure 8). Page 11

16 User Button: The user clicks on this button to enter his identification name. The validation is achieved by return. Password Button: The user clicks on this button to enter his password. The password is not displayed. The validation is done by return. Exit: The user clicks on this button to close the Log On Window. Figure 8 Log On Window To log-on as an administrator Depending on the access level of the logged user, two additional buttons may appear (see Figure 8): Configure Users: This button allows the operator to configure all the users and is only available to the administrator. Resources: This button allows the user to access the System Resources window, which gives information on the system (see Figure 9). It also allows the user to exit the S10 software so that the PC may be shut down. After logging in, the key appears and indicates the name of the user and the user s access level Figure 7 shows a logged on window with user s access level of 9999 for administrator. In order to increase the security, an automatic log-off is used: when no actions are carried out on the keyboard or with the mouse for 5 minutes, the operator is automatically logged off and can not access the control functions. Logging off A click on the logged-on key will turn the key to the off position. QUIT MiCOM S10 application This function can only be used by an Administrator. Exiting the MiCOM S10 will stop all the records (events, measurement, ) and will close all the views. To QUIT the application, on the System Resources view, click on the button QUIT MiCOM S10 (see Figure 9). Page 12

17 NOTE: Before exiting, an operator confirmation is required. Figure 9 System Resources Screen, with Quit Micom S10 Button. 2.4 The Overview Screen Figure 10 System Overview Screen Clicking on 'Overview' in the drop-down menu of the Site Screen produces the PSS System Screen. This screen shows all the components of the PSS, positioned approximately as seen on the front panel of the PSS. The Overview Screen also shows the status of all the CBs (open or closed). Red lines are for 415 V supply Blue lines are for 220 V supply Black lines are for 110 V supply Page 13

18 The identification and numbering of circuit breakers, meters and relays, four-pin connectors and lines, links and loads are also as given on the front panel of the PSS. Click on the yellow return button to return to the Site Screen. Relays and meters, Generator excitation current and voltage, load angle, and RPM are shown in red. If these red text blocks are clicked, the System Screen for the meter or relay can be accessed, providing additional information. Note that the current, steady state voltage obtained from the meters is shown alongside the corresponding red identification button (on selected instruments). Circuit Breakers are shown in both the open state (see CB3) and the closed state (CB4) (see Figure 10). Provided the operator has the required level of authority (see Appendix 2) all CBs except CB1,CB13 & CB17 can be opened or closed remotely by clicking on them. Relays are shown in a box showing the position of the trip and override lamps. (see Appendix 4, PSS Manual). Faults can be applied remotely by clicking on either the Timed Fault CB or the Manual Fault CB. In the centre of the Overview Screen are three buttons: Accept, Reset, and Lamp Test. These buttons have the same function as those on the PSS: 'Accept' to cancel the fault alarm; 'Reset' to reset the protection relays and 'Lamp Test' to test the relay alarm lamps. The twelve manual switches in the Double-Bus system, shown in blue, have to be closed manually on the PSS. An Emergency Stop button is shown on the right side of the Screen, which, if clicked, switches the PSS off. 2.5 The Bay Screen Figure 11 The Bay Screen In practice, power system Sites are divided into Substations, which can be further divided into 'Bays'. Bays usually contain circuit breakers, relays, and maybe a transformer. These Bays are accessed from the Substation view by clicking on the button with the name of the Bay. See page 17 in the MiCOM S10 User Guide. In the present application the red, named buttons for meters and relays in the System Overview and Experiment Screens replace the buttons for Bays. Clicking on a meter or relay button in the System Overview and Experiment Screens accesses a Bay Screen as shown in Figure 11. The screen shows the following information: Bay Relay/Meter icon Current alarms. Acknowledgement is subject to access rights Page 14

19 Real time trends: voltage, currents and powers for the previous hour Measures; real-time values of the relay/meter measurements The most important relay settings A click on the relay/meter icon will lead to more detailed information of the device, on a Systems screen. 2.6 System Screens Figure 12 System Tab - KITZ 101 and M1400 Converter The 'System' is a separate section of the S10 program and has its own tab on the bottom bar. The Areva User Guide refers to this section as a 'Maintenance System'. Clicking on the 'System' tab produces the screen shown in Figure 12. It shows the two main serial converters for the communications system: The KITZ 101 converter for Courier and the M1400 converter for Modbus. Page 15

20 Figure 13 System Tab - KITZ Communication Spur (Courier) Clicking on each converter shows the connection of individual relays and meters in the PSS. Clicking on the KITZ 101, 'protection' icon produces the string of relays as shown in Figure 13. The relay icons have illuminated windows: green indicates a healthy state, red an unhealthy state and a flashing red indicates loss of communications. A white window indicates a device that is not connected. Figure 14 System Tab - M1400 Communication Spur (Modbus) Clicking on the 'metering' icon in Figure 12 produces the System Screen shown in Figure 14. Each meter (M230s and DH96s) has a numerical address, shown on the icons. The numerical address is for identification of the instrument within the communication system. Note that the Grid Transformer Relay, P632, is also connected to the Modbus. Each relay and meter has its MiCOM number and its identification tag within the PSS. See the PSS Manual, and Appendix 4 of this manual for a listing of numerical addresses for relays and meters. Page 16

21 Figure 15 System Screen for the RD2B P142 Relay Clicking on any meter or relay in Figures 13 and 14 will bring up a 'System' Screen showing a detailed view of the meter or relay. Figure 15 shows the System Screen for relay RD2B, the MiCOM P142 relay. Here the relay liquid crystal display (LCD) is shown in Green, which means the relay is healthy. 'Red' indicates 'unhealthy' and white an 'unknown state'. On the right half of the Screen are the current alarms within the relay. The Disturbance view gives the status of disturbance recordings within the relay. A button on the far left of the Screen enables the 'status' to be changed to in/out of service. Several buttons in the top right corner of the window allow the user to access measures acquired by the relay. A click on one of these buttons accesses the related window. 2.7 Navigating between System and Overview Screens In the previous Sections two separate paths, Overview and System, have been referred to. Descriptions of the two paths in previous Sections have been progressive. No mention has been made of how to return to the Site Screen. Return from Overview tab Screens, from a Bay Screen to Experiment Screen, to Site Screen, is achieved by clicking on a yellow button positioned at the top left hand corner of the Screens. These include all individual Experiment screens and individual relay and meter screens. Moving between a System Screen and an Overview Screen, or between System Screens is not so obvious. Figure 16 gives a navigational 'tree' for moving between Overview and System. Page 17

22 Figure 16 Navigation Between Screens Page 18

23 SECTION 3.0 Remote Control of the Power System Simulator At the top of the Experiment Screens there is a 'Control Panel' button for accessing the Control Panel, shown in Figure 17. The Control Panel is used for controlling the generator and adjusting the load. Figure 17 Control Panel Button Click on the yellow 'return' button at the top left hand corner of the Control Screen to return to the Overview or Experiment Screen where the Control Panel button was clicked on. 3.1 The Control Panel The Control Panel contains controls for the resistive and inductive loads, the Generator, the Dynamic Load and the Manual Fault CB and the Timer Fault CB. The resistive and inductive loads, Loadbanks 1, 2, 3 and 4, are clearly marked on the left and right of the screen. Loadbank 1 contains controls for the Generator 1 loads, L1 and R1. Loadbank 2 and 3 contains controls of the Distribution Bus Loads, R2 and L2, and R3 and L3. Loadbank 4 contains controls for the Generator loads, Loads L2 and R2. They are termed Generator 2 loads because of their position on the PSS panel, but they can be used for general 220 V system loading. Figure 18 The Control Panel The Resistive and Inductive loads each have 'Raise' (+) and 'Lower' (-) buttons; one for each of the red, yellow and blue phases, and two longer buttons for raising (+) or lowering (-) the load for all three phases together. 'Raise' and 'Lower' refer to load current. These buttons do not work (greyed out) until the load switches on the PSS are set to variable. Page 19

24 The grey lights turn red, yellow and blue when the corresponding phase button is clicked. The raise and lower buttons control motorised pots on the PSS. These pots vary the voltage applied to the resistors and inductors. A 'Reset Loads' button is shown at the bottom right of the Screen. When clicked on, this control will return the load currents to zero. Note: There is always a slight delay from when you click on the buttons to when the load changes. Continuous monitoring of the line currents and line voltages (Vab, Vbc, Vca), power and power factor are provided at four points in the PSS; they are: Grid Supply: Generator 1 Supply: Left-hand branch of Distribution network: Right-hand branch of Distribution network: MB MD MM MP Additionally the red hyperlink text marked MB, MD, MM and MP can be clicked on to access the system screens for these meters, providing additional information. Generator Control Panel This panel controls many of the functions of the Generator 1, but not the synchronisation of the generator to the Grid Supply via CB8, which has to be carried out manually on the PSS. The panel shows 'Start' and 'Stop' buttons for the induction motor driving the generator. The buttons change from black to green and to red, correspondingly, when activated. When the induction motor has been started, a spinning symbol appears, just above the start button. The speed of the generator can be raised or lowered by means of the 'Raise' (+) and 'Lower' (-) buttons, and the speed observed in the Generator Control panel. When the generator is synchronised, the speed/power pot controls the output power of the generator to the Grid, which can be observed on meters MD and MB. Excitation of the generator can be raised or lowered following closure of the 'Field CB'. The 'Field CB' button shows the status of the circuit breaker: 'closed' or 'open'. The output voltage of the generator can be viewed on meter MD. Note: There is always a slight delay in the data transfer from the actual meters on the PSS to the mimics on the SCADA. Dynamic Load Panel The induction motor on the PSS that provides a 'Dynamic Load' is fed from the Utilization Bus. The motor is started by clicking on the circuit breaker button, CB34. When the induction motor has started, a spinning symbol appears, just above the CB34 symbol. 'Raise'(+) and 'lower'(-) buttons are provided for varying the motor load. The current taken by the Dynamic load can be observed on meter MP. Clicking on CB34 will open the breaker. Fault Application Faults can be applied remotely by clicking on either the 'Timed Fault CB' or the 'Manual Fault CB', shown at the bottom right of the screen. The CB symbol (shown in the open position) will change to a closed position when clicked on. Note: The timed fault CB changes state (open or closed) for the time set in the fault timer on the PSS. Page 20

25 SECTION 4.0 Reading Fault and Measured Data During and at the end of each experiment it is necessary to extract measured or recorded values of quantities from the relays and meters. This section describes the means provided by the S10 software for data display and extraction. 4.1 Measured Values of System Quantities Measurements of system quantities, such as voltages and currents are needed when setting up all experiments and in carrying out experiments on the operation of power systems under both load and fault conditions. Measurement records contain RMS and magnitude values of quantities such as voltage and current as well as values of integrated quantities such as power, reactive power and energy. These records can be viewed on the relay or on a PC connected to the front port. True r.m.s values are given for steady state power system operation and are calculated by the relay from the sum of the measured samples squared over a cycle of sampled data. Magnitude values of voltages and currents are listed normally in the Fault Records of relay menus. Phase angles are also given as well as sequence values and earth currents. These values are produced directly from the Discrete Fourier Transform of measured samples of current and voltage. The magnitude of a quantity refers to the RMS value of the Fourier fundamental component. The relay protection functions use these values. Note: The current values listed in Fault Records are the values recorded at the time the threshold current was exceeded. There are two ways of accessing measured information: the Measures Screen and the Systems Screen for each meter and relay. The following sections describe these screens and the measurements they provide. The Measures Screen A Measures button at the top of the Experiment Screens and Control Screen gives access to a summary list of all meters and relays on the PSS and their current, voltage, power and energy readings (see Figure 19). Return from this Screen to Experiment Screen or Control Screen is via the yellow return button. On certain steady-state Experiment Screens, selected parameters for selected meters are displayed to aid the user. Figure 19 The Measures Screen Page 21

26 4.2 Measurements from System Screens All Experiment Screens have red buttons for the M230 and DH96 Meters and all Relays. Clicking on a red button gains access to the System Screen for the meter or relay. They can also be accessed via the System tab on the bottom bar of all Screens. The System Screens for meters and relays enable access to Measurements and Disturbance records. Measurement records include both steady state and fault values. Micom M230 Meters The System Screens for the M230 meters are shown in Figures 20 and 21. Clicking on the Main and Power buttons in the top right hand corner of the System Screen gains access to the measured values shown in Table 1. Current and voltage values are true r.m.s. Only the important readings from each meter are shown. Figure 20 System Screen for the M230 Meters Figure 21 Measured Values Screen for the M230 Meters Page 22

27 Type M230 M230 M230 M230 M230 M230 M230 M230 M230 M230 M230 M230 M230 M230 M230 M230 M230 M230 M230 M230 M230 M230 M230 M230 M230 Label 3 PHASE APPARENT POWER 3 PHASE REACTIVE POWER 3PHASE ACTIVE POWER APPARENT POWER PHASE A APPARENT POWER PHASE B APPARENT POWER PHASE C IA IB IC POWER FACTOR POWER FACTOR A POWER FACTOR B POWER FACTOR C POWER WA POWER WB POWER WC REACTIVE POWER PHASE A REACTIVE POWER PHASE B REACTIVE POWER PHASE C VA VAB VB VBC VC VCA Table 1 Measurement Values for the M230 Meters Page 23

28 Micom P122 Relays The System Screen for the P122 relays is shown in Figure 22. Figure 22 System Screen for the P122 Relays The two P122 relays, RG1B and RG2B, have similar System Screens as shown in Figure 22. The list of measurements obtained in the Main menu is shown in Table 2. Current and voltage values are RMS. Fault values of current can be obtained by accessing from the System Screen the Last Fault Records. Current values here are magnitude. Type Label P122 P122 P122 P122 P122 P122 I0 I1 I2 IA IB IC Table 2 Measurements Obtained in the Main Menu for P122 RG1B and RG2B Relays Page 24

29 Micom P142 Relays The System Screen for a P142 relay is shown in Figure 23. Figure 23 System Screen for a P142 Relay The list of measured quantities in all TQ, P142 Relays is given in Table 3. They have been taken mostly from Measurement 1 and Measurement 2 in the Relay Menu. The current IA is an RMS value. IA Magnitude from the fault records is needed in fault studies. Type Label P142 P142 P142 P142 I0 IA IB IC Table 3 Measured Quantities in the P142 Relays Page 25

30 Micom P343 Generator Protection The System Screen for the P343 relay is shown in Figure 24. Figure 24 System Screen for the P343 Relay. Once again there is a mixture of RMS and Magnitude values for currents and voltages. See Table 4. Type P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 Label 3 PHASE APPARENT POWER 3 PHASE REACTIVE POWER 3 PHASE ACTIVE POWER APPARENT POWER PHASE A APPARENT POWER PHASE B APPARENT POWER PHASE C FREQUENCY I NEUTRAL I0 I1 I2 IA BIAS IA DIFF IA MAGNITUDE IA RMS IB BIAS Continued... Page 26

31 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 P343 IB DIFF IB MAGNITUDE IB RMS IC BIAS IC DIFF IC MAGNITUDE IC RMS IC-2 MAGNITUDE POWER FACTOR POWER FACTOR A POWER FACTOR B POWER FACTOR C POWER WA POWER WB POWER WC REACTIVE POWER PHASE A REACTIVE POWER PHASE B REACTIVE POWER PHASE C SUM (OPS) V NEUTRAL V NEUTRAL DERIVED V0 V1 V2 VA VA RMS VAB VB VB RMS VBC VC VC RMS VCA Table 4 Measured Quantities in the P343 Relay Page 27

32 Micom P442 Distance Protection The System Screen for the P442 relay is shown in Figure 25. Figure 25 System Screen for the P442 Relay In addition to the RMS values of current and voltage shown in Table 5, three relevant quantities for Distance Protection are given: Faulted Phase Fault location (metres) Fault Zone Type P442 P442 P442 P442 P442 P442 P442 P442 P442 P442 Label 3 PHASE APPARENT POWER 3 PHASE REACTIVE POWER 3PHASE ACTIVE POWER APPARENT POWER PHASE A APPARENT POWER PHASE B APPARENT POWER PHASE C FREQUENCY I0 I1 I2 Continued... Page 28

33 P442 P442 P442 P442 P442 P442 P442 P442 P442 P442 P442 P442 P442 P442 P442 P442 P442 P442 P442 P442 P442 P442 P442 P442 IA IB IC NB 1PHASE RECLOSE NB 3PHASE RECLOSE POWER FACTOR POWER FACTOR A POWER FACTOR B POWER FACTOR C POWER WA POWER WB POWER WC REACTIVE POWER PHASE A REACTIVE POWER PHASE B REACTIVE POWER PHASE C V0 V1 V2 VA VAB VB VBC VC VCA Table 5 Measured Quantities in the P442 Relay Page 29

34 Micom P632 Grid Transformer Protection The quantities shown in Table 6 have been chosen for the two winding Grid Transformer Protection in the PSS. Figure 26 System Screen for the P632 Relay Type P632 P632 P632 P632 P632 P632 P632 P632 P632 P632 Label ANGLE phi AB end a ANGLE phi AB end b CURRENT IA a prim CURRENT IA b prim CURRENT IB a prim CURRENT IB b prim CURRENT IC a prim CURRENT IC b prim CURRENT IN b prim CURRENT IY b prim P632 DIFF CURRENT 1 P632 DIFF CURRENT REF 2 P632 DIFF RESTRAIN CURRENT 1 P632 RESTRAIN CURRENT REF 2 P632 VOLTAGE V prim Table 6 Measured Quantities in the P632 Relay Note: INb prim is a vector sum and IYb prim is a measured neutral current. DiffCurrent1/DiffCurrentRestrain1 refers to the main differential protection using measuring system 1 (there are 3). DiffCurrentREF2/RestrainCurrentREF2 refers to the Restricted Earth Fault Protection on the starsecondary of the Grid Transformer. Page 30

35 4.3 Sequence of Events Recording (SOE) and Alarms The sequence of events and alarms are closely related. Data from the relays is communicated to SOE or Alarms within the S10 software. The data contains information on defined events, or labels, for each converter or relay. These labels are relevant to either or both the SOE and Alarms. There are two label states for the Alarms, 0 or 1. Label state 1 indicates a SET condition. Label state 0 indicates a RESET condition. SET indicates an operate condition. RESET indicates Not operated. Sequence of Events Recording (SOE) Viewing the SOE Screen Click on the SOE tab on the bottom bar to access the SOE Screen. The SOE Screen is shown in Figure 27. Figure 27 Typical SOE Screen Events are recorded and described in the relays and time stamped using the relay s clock (when available). The main screen view displays a list of sequence of events. It displays event date, time the event occurred ( time stamped to a resolution of 1 millisecond), comment and event value/status. Example of SOE wording. Date // hh:mn,mn:s.s.ms.ms.ms // D1 label or system information // status Updating and viewing the events. On the right hand side of the SOE Screen a column of control buttons is seen, described as follows: Max.records: This numerical field allows the user to enter the number of records to be displayed. Click on the value to modify the number of events that are present on the view. Auto update: The SOE screen automatically updates when the button is clicked. The alternative is to update the listing using the manual update button (see below). With the auto update function, the maximum of records is automatically programmed to 20 records (auto updated each 5 sec.) Page 31

36 Manual update: Clicking on this button updates the SOE. Event filter/set filter: A filter can be set to extract a subset of the events (for example to issue a report). View: Allows the SOE saved file to be viewed, using the Windows NT Notepad. Managing the SOE records Several buttons may appear in the right hand column, depending on the access level of the logged-on operator. Clear recorder: This button allows the SOE recording to be cleared using different methods. File name: This box allows the SOE listing to be sent to another file. The name of the file is entered in the box. (They can be only files present on the SOE screen) Save: This button the SOE listing to be saved to file specified in File name. Delete: This button allows a saved file to be deleted. Filtering the SOE records The SOE list may be made more selective by using the Set Filter button. This displays the SOE Filter window, which enables the filter parameters to be selected by date and/or alarm group. To set the filter, on the SOE screen, click on Set Filter. The SOE Filter view is displayed. When the relevant information has been entered into the boxes, set the event filter to on, click on update filter and then exit the screen to set the filter. Deleting SOE files SOE clearing is possible depending on the access level of the logged-on user. To access the SOE clearing window, while displaying the SOE screen, click on the Clear recorder button. The SOE clearing window appears. It is possible to clear all or part of the record: All: Clears all the recorded events Keep xx data: Clears all but keep the xx newest data s from 1000 to Automatic keep xx data: As the previous clear instruction, but this is automatically done every hour from 1000 to To date: Enables a date to be entered. All events before this date are cleared. (enter day, month, and year (from 00 to 99). Page 32

37 System Alarms For each alarm, a record is stored and a line is added on the alarm page view. Viewing the alarm page To access the Alarm view, click on the tab on the bottom bar. The alarm screen is shown in Figure 28. The control bar for this Screen is shown along the bottom of the Screen. Figure 28 Alarm Screen The information given for each alarm is as follows (from left to right). The alarms that have been displayed are colour coded according to their status. Green: Returned Alarm a system alarm that has returned to a Healthy state. Red: Unacknowledged alarm. Blue: Acknowledged alarm. Date: Date alarm has been recorded (DD/MM/YY) Time: Time alarm has been recorded (HH/MM/SS) Status: Acknowledged, unacknowledged Priority: Alarm priority defined by the user (0-999) Comment: Device or function that has been alarmed Value: Value that caused the alarm An example of the use of these colour codes is shown in Figure 29. The list shows that KBUS ACO PO-1 is blue when Acknowledged (ACK) but still has an ERROR status. However, when the fault on KBUS has been cleared, ACK changes to ACK_RTN, the status changes to OK and the colour changes to green. The total number of alarms in the current page is indicated in the box on the left of the bottom bar. Page 33

38 Red Green Blue Figure 29 An Example of the Colour Codes for Acknowledged Alarms Filtering the alarms Many functions are offered on the bottom bar to filter lists of alarms: Priority: Selecting the alarms with their priority (the priority of an alarm is defined during the configuration phase) List: An operator can select historical list, with all the recorded alarms or the Alarm list with the current alarms Show: The selection is based on the alarm status: Acknowledged alarms, non acknowledged alarms, all the alarms Group: To enable filtering of the alarms by group: for example to only show the alarms from a bay Acknowledging the alarms Several acknowledging buttons will appear on the right hand side of the bottom bar according to the access rights of the logged on operator: Ack Page: Click on this button to acknowledge all the displayed alarms on the page. Ack Select: Click on this button to acknowledge all the selected alarms. To Select an alarm, click on the line with the description of the alarm; it will be underlined. Ack New: Click on this button to acknowledge the last alarm. Ack All: Click on this button to acknowledge all the alarms. In order to stop the local PC buzzer (used when alarms are present), the operator will click on the red flashing light in the top bar (on the left of the 3 recorded alarms). Page 34

39 4.4 The Software Tools Tab Disturbance records store typically 20 records each of 10.5 seconds long. Data is sampled 12 times a cycle. In most relays, up to 8 analogue channels, 32 digital channels and one time channel is available. The pre and post fault time can be set by accessing the relay menus. These records are in graphical form and can be examined from the front port of the relay by PC and S1 MiCOM software. Disturbance records are routinely extracted by the SCADA system and stored on the PC. Disturbance data is displayed and analysis assisted by the 'Win Analyse' software. To access the 'WinAnalyse' software on the SCADA, click on the 'Software' tab on the bottom bar of the Site or other Screens. A pop-up menu is produced as shown in Figure 30. Four buttons are shown: Win Analyse, Micom S1, NSM and Oscilloscope. Win Analyse provides software tools for retrieving and analyzing the Disturbance records stored on the PC Hard disk. The operator rights required to access these functions are at least 'Relay Maintenance', or >2000. The Micom S1 is the software package for setting the operational parameters of the protection relays. Operation of this utility is detailed in the Areva S1 User Guide. 'NSM' stands for Network Support Manager. This package is used by an instructor to provide facilities to any additional seats. For details, refer to the Network Support Manager User Guide. The Oscilloscope button enables fault traces captured on the Hameg oscilloscope to be viewed and analysed. Pop-up menu Figure 30 The Software Tab. Win Analyse Software Click on the Win Analyse button to access the software. A blank Win Analyse screen appears with an access bar showing, File, Configuration, Analysis, Calculation, Window (and Help). Click on File and again on Open in the drop down menu. An 'Open Event' box appears (see Figure 31). Page 35

40 Figure 31 Open Event Box The first column 'Stations' lists relay locations in this application. The second column 'Events' lists events of the selected station. Double click on the event selected to produce two windows; a 'header' and a 'curves' window. Figure 32 Header Window The header window shown in Figure 32, contains text detailing quantities and data relevant to the event. The curves window shown in Figure 33, displays the graphics screens and analogue and logic signals recorded by the disturbance recorder. The curves window has a comprehensive toolbar for measurements of the curves displayed. Access the Win Analyse manual (33 pages) on the PC for further, detailed information on the application of the software. Page 36

41 Figure 33 Curves Window The Oscilloscope Screen Figure 34 The Hameg Oscilloscope Screen Figure 34 shows the Hameg Oscilloscope Screen. Refer to the Hameg Manual for explanation of the Screen and instruction on its use. Page 37

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43 SECTION 5.0 Experiment Screens 5.1 Introduction The drop-down list in the Site Screen shows that there is a selection of Experiment Screens in the Overview Section. Each Screen corresponds to a numbered experiment in the main PSS User Guide. They are listed in Table 7. If you have a Second Generator (NE9272) attached to the PSS, extra experiments will appear that are unique to the Second Generator (see Table 8). Each experiment has a main title and a second title. The main title of an experiment denotes the area of power engineering to which the experiment relates. The second title refers to a particular operational condition within that area. The main PSS User Guide (and Second Generator User Guide where fitted) should be used in conjunction with the SCADA User Guide in carrying out experiments. A suggested procedure is given for each experiment together with a picture of the relevant Experiment Screen. For clarity, the Connection Diagrams in the PSS User Guide (and Second Generator Guide) are also provided in APPENDIX 3 of this User Guide. PSS Experiment Numbers Main Title Second Title 2 Generator Control VEE Curves 3 Generator Control P-Q Chart 4 System Voltage Regulation P-Q Flow 5 System Voltage Regulation Constant P.F Load 6d 3 Phase Transformers Unbalanced Load 6c 3 Phase Transformers Unequal Impedances 6b 3 Phase Transformers Unequal Taps 7 Load Flow Three Bus System 8a Symmetrical Faults Unloaded System 8b Symmetrical Faults Loaded System 8c Symmetrical Faults Four Bus System 8d Symmetrical Faults Induction Motor Contribution 9a Unsymmetrical Faults I 2 Measurement 9b Unsymmetrical Faults Transmission Line Faults 9c Unsymmetrical Faults TX Terminated Line 9d Unsymmetrical Faults Double End Feed 12 OC Protection Relay Grading 13 OC Protection Auto-Reclose 14 OC Protection Instantaneous High Set 15 OC Protection Back trip 16 OC Protection Directional Control 17 Distance Protection 18 Grid TX Protection 19 Bus Bar Protection 20 Generator Protection Table 7 PSS Experiments Page 39

44 Second Generator Experiment Numbers Main Title Second Title 23 Second Generator Generators in Parallel 24 Second Generator VAr Control 25 Second Generator Power Factor Control 26 Second Generator P & Q Flow in Dist System Table 8 Second Generator Experiments 5.2 Features of Each Screen Each Experiment Screen has the following features: A one-line diagram of the circuit being investigated, Red, blue and black lines refer to 415 V, 220 V and 110 V, respectively. All flexible connections between 4-pin sockets are in green. CBs may be opened or closed by clicking on the screen symbol. Test points are shown where relevant to the experiment. All flexible connections will flash for about 10 seconds when an Experiment Screen is switched on. In some experiments the type of fault and the Test points may be selected. Relays, meters and generator excitation that can be accessed are shown as red hyperlinks. Clicking on these buttons produces the System Screen for the particular device or feature. See Section 2. All Experiment Screens have a Control Panel Button and a Measures button, as previously discussed. Return to the relevant Experiment Screen is achieved by clicking on the yellow return button. To change an Experiment Screen, click on the yellow return button to return to the Site Screen. Click on the required Experiment in the drop down list of experiments. Circuit breakesr on the PSS (or Second Generator) can be remotely opened or closed by clicking on the corresponding symbol in the Overview and Experiment Screens; with the following exceptions: CB1: controlled by the Grid Transformer relay. The relay becomes operative when the PSS is switched on. After completing a self-check procedure, the relay switches on CB1. CB13 and CB17: the bus coupler relays. These are monitored, but cannot be controlled. CB8 and CB2: For non-synchronised Experiments, CB8 and CB2 can be opened or closed remotely. However if (CB3 or CB4) AND (CB5 or CB6) are closed, either CB2 or CB8 can be closed remotely, but they cannot both be closed. This is to prevent accidental remote crash synchronization at the Generator and Grid Supply. CB8 cannot be closed when the PSS generator is stationary. Note: Before you start any experiment, make sure all the relays on the PSS are set to default settings. Page 40

45 Experiment 2: Generator Control - Vee Curves Procedure 1) With the PSS switched off, connect the circuit as shown in Figure 68. Set the speed/power and excitation controls for the generator to zero. Set the inertia switch to position 1. Switch on the PSS. 2) Start up the S10 on the PC and access the Vee Curves Experiment Screen as shown in Figure 35. Figure 35 Vee Curves Experiment Screen 3) On the Experiment Screen close all CBs except CB8. Check CBF is open. Click on the Control Panel button. 4) Generator speed, and field quantities can be controlled from the Generator Control Panel. Start the generator. Increase the speed to 1500 rev.min -1 (50 Hz PSS) or 1800 rev.min -1 (60 Hz PSS). Close the Field CB and increase the excitation to obtain approximately 220 V on meter MD. 5) Go to the PSS. Synchronize the Generator to the Grid by manually closing CB8 (as described in Section 5 of the PSS User Guide). Return to the Experiment Screen. 6) Monitor the Generator excitation voltage, current and the speed. 7) Monitor the line current, I a, and the power factor on meters MB and MC. 8) Use the generator raise and lower buttons to set the power output to 0.25 kw (shown on meter MB). 9) Vary the excitation current to vary I a and power factor. Record values of I a, VArs and power factor for various values of excitation current, I f (field current). 10) Repeat for other values of power output (refer to the PSS User Guide). 11) At the end of the experiment decrease the power output from the generator to a low value and manually open CB8. Reduce excitation to generator and open CBF manually. Stop the motor, either remotely or at the PSS. Page 41

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47 Experiment 3: Generator Control - P Q Chart Procedure 1) With the PSS switched off connect the circuit as shown in Figure 68. Set the speed/power and excitation controls for the generator to zero. Switch on the PSS. 2) Start up the S10 on the PC and access the P-Q Chart Experiment Screen, as shown in Figure 36. Figure 36 P-Q Chart Experiment Screen 3) On the Experiment Screen close all CBs, except CB8. Check CBF is open. Go to the Control Panel on the PC. 4) Generator speed, and field quantities can be controlled from the Generator Control Panel. Start the generator. Increase the speed to 1500 rev.min -1 (50 Hz PSS) or 1800 rev.min -1 (60 Hz PSS). Close the Field CB and increase the excitation to obtain 220 V on meter MD. 5) Go to the PSS. Synchronize the Generator to the Grid by manually closing CB8 (as described in Section 5 of the PSS User Guide). 6) Return to the Experiment Screen and monitor the excitation voltage, current and the speed. 7) On meter MB, monitor the line current, I a, and the power factor. 8) Set the power at 2 kw. Increase the excitation to keep the power factor at unity. Note the load angle of the generator. 9) Now continue from item 4, (Section 5, Experiment 3) of the PSS User Guide, using the controls on the Generator Panel, and taking readings from meter MB. 10) Repeat for two or three other values of power output (refer to the PSS User Guide). 11) At the end of the experiment decrease the power output from the generator to a low value and manually open CB8. Reduce the excitation of the generator and open CBF manually. Stop the motor, either remotely or at the PSS. Page 43

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49 Experiment 4: System Voltage Regulation - P-Q Flow Procedure 1) With the PSS switched off and all CBs open, connect the circuit as shown in Figure 69. Set the speed/power and excitation controls for the generator to zero. Set the resistive and inductive load pots (R2+L2) to zero. Set the loads L2 and R2 to 50%, and L3 and R3 to 25%. Switch on the PSS. 2) Start up the S10 on the PC and access the P - Q Flow Experiment as shown in Figure 37. Figure 37 P-Q Flow Experiment Screen 3) Go to the Control Panel Screen on the PC. Generator speed, and field quantities can be controlled from the Generator Control Panel. On the Generator Control Panel start the motor for the Generator and adjust the speed to 1500 rev.min -1 (50 Hz PSS) or 1800 rev.min -1 (60 Hz PSS) using the raise/ lower buttons. 4) Close the field circuit CBF and adjust the excitation to 220 V on meter MD. 5) On the Experiment Screen close CBs 8, 20, 23, 25 and 33 (25% resistive load). 6) Adjust the excitation of the Generator to maintain Vr equal to 220 V at the Distribution Busbar 1, shown on meter ML. Read the power at meter MM. 7) Open CB33 and close CB28 (to give 50% resistive load). 8) Re-adjust the generator excitation to give 220 V and record the power indicated by MM. 9) Leave CB28 closed and close CB33 (to give 75% resistive load). Repeat step 8. 10) Open CB33 and close CB32 (to give 50% resistive and 25% inductive load). Repeat step 8. 11) Open CB32 and close CB29 (to give 50% resistive and 50% inductive load). Repeat step 8. 12) Close CB32 (to give 50% resistive and 75% inductive load). Repeat step 8. 13) At the end of the Experiment reduce the load, generator excitation and speed to a minimum before opening all CBs including CBF. Stop the motor. Refer to Experiment 4 of the PSS User Guide for details of the phasor diagram construction. Page 45

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51 Experiment 5: System Voltage Regulation - Constant PF Load Procedure 1) With the PSS switched off and all CBs open, connect the circuit as shown in Figure 69. Set the speed/power and excitation controls for the generator to zero. Set all resistive and inductive load pots and switches to off. Switch on the PSS. 2) Start up the S10 on the PC and access the Const PF Load Experiment Screen as shown in Figure 38. Figure 38 Constant PF Load Experiment Screen 3) Go to the Control Panel Screen on the PC. Lower the Speed/power and Excitation controls to their minimum values. On the Generator Control Panel start the motor for the Generator and use the raise/ lower buttons to adjust the speed to 1500 rev.min -1 (50 Hz PSS) or 1800 rev.min -1 (60 Hz PSS). 4) Close the field circuit CBF and adjust the excitation to 220 V on meter MD. 5) Go to the Experiment Screen and close all CB8, 20, 23, and 25. 6) Adjust the excitation of the Generator to obtain Vr equal to 220 V at the Distribution Busbar 1, shown on meter ML. 7) Note the value of the voltage at the Generator bus, Vs, on meter MD. 8) Close CB32, and 33 (to give 25% resistive and 25% inductive load). Record the readings of meters MD and ML. 9) Open CB32 and 33, close CB28 and 29 (to give 50% resistive and 50% inductive load). Record the readings of meters MD and ML. 10) Close CB32 and 33, leave CB28 and 29 closed (to give 75% resistive and 75% inductive load). Record the readings of meters MD and ML. 11) At the end of the experiment, reduce the load generator excitation and speed to a minimum and stop the motor. Open manually all CBs including CBF. 12) Refer to experiment 5 in the PSS User Guide for an explanation of your results. Page 47

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53 Experiment 6b: Three-phase Transformers - Unequal Taps Procedure 1) With PSS switched off and all CBs open, connect the circuit as shown in Figure 70. Set all resistive and inductive load controls to zero. Make sure the taps for both transformers are 0%. Switch on the PSS. 2) Start the S10 program on the PC and access the Unequal Taps Experiment, as shown in Figure 39. Figure 39 Unequal Taps Experiment Screen 3) On the Experiment Screen, close all the CBs within the circuit. 4) Monitor the voltages and currents and powers on meters MM, ML, MN and MP. 5) Open manually CB2 on the PSS and change the tap on one transformer to +2.5%. 6) Close CB2 (manually, or on the Experiment Screen on the PC). Monitor the voltages, currents and powers on meters MM, ML, MN and MP. 7) Repeat for other transformer taps. 8) To close the experiment open CB2. Page 49

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55 Experiment 6c: Three-Phase Transformers - Unequal Impedances Procedure 1) With the PSS switched off and all CBs open, connect the circuit as shown in Figure 70. Set resistive load R2 and inductive load L2 to 50%. Set all other load controls to zero. Make sure the taps for both transformers are 0%. Switch on the PSS. 2) Start the S10 program on the PC and access the Unequal Impedances Experiment, as shown in Figure 40. Figure 40 Unequal Impedances Experiment Screen 3) In the correct order, on the Experiment Screen, close CB2, 3, 20 and 22 to 27. Now close the manual fault switch. 4) Monitor the voltages, currents and powers on meters MM, ML, MN and MP. 5) Close CB28 and 29 (to give 50% resistive and 50% inductive load). Monitor the voltages, currents and powers on meters MM, ML, MN and MP. 6) Open the manual fault switch to insert a line impendance of 0.1 pu into the right hand transformer circuit. Monitor the voltages, currents and powers on meters MM, ML, MN and MP. 7) Open CB2 to complete the experiment. Page 51

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57 Experiment 6d: Three-Phase Transformers - Unbalanced Load. Procedure 1) With PSS switched off and all CBs open, connect the circuit as shown in Figure 70. Set resistive load R3 to 50%. Set all other resistive and inductive load controls to zero. Switch on the PSS. 2) Start the S10 program on the PC and access the Unbalanced Load Experiment, as shown in Figure 41. Figure 41 Unbalanced Load Experiment Screen 3) In the correct order, on the Experiment Screen, close CB2, 3, 20 and 22 to 27. Now close the manual fault switch and CB33. 4) Monitor the voltages, currents and powers on meters MM, ML, MN and MP. 5) Open the manual fault switch to open the yellow phase circuit. Monitor the voltages, currents and powers on meters MM, ML, MN and MP. 6) At the end of the experiment reduce the load to minimum and open CB2, or switch off the PSS. Page 53

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59 Experiment 7: Load Flow Study - Three Bus System This is an experiment with the more general objectives of observing the change in current, power and reactive power flow around a system with change in load and bus voltages. The Measures Screen is useful here in providing a view of currents and voltages for all meters and relays in the Power System in a single list. The relative angles, δ2 and δ3 for V2 and V3, respectively, cannot be seen on screen. They must be measured on the PSS using the phase angle meter. Procedure 1) With the PSS switched off and all CBs open, connect the circuit as shown in Figure 71. Set the resistive and inductive loads R2 and L2 to 50%. Set the resistive and inductive loads R3 and L3 to 25%. Set all other resistive and inductive load controls to zero. Set the speed/power and excitation controls for the generator to zero. 2) Start the S10 program on the PC and access the Three Bus System Experiment Screen as shown in Figure 42. Figure 42 Three Bus Experiment Screen 3) In the correct order, on the Experiment Screen, close CB22, 28, 27, 25, 23, 20, 14, 3, 2, 11, 12, 5, 6, 16, 18, 21, 23, 24, 25, 26. Note: You must close the CBs in the correct order, this is because CB11 is a thyristor based switch and must have enough load to work correctly. If it does not have the load at the correct time, a fault will occur. 4) Go to the Control Panel Screen. Lower the Speed/power and Excitation controls to their minimum values. Start the motor for the Generator and use the raise/ lower buttons to adjust the speed to 1500 rev.min -1 (50 Hz PSS) or 1800 rev.min -1 (60 Hz PSS). 5) Close the field circuit CBF and adjust the excitation to 220 V on meter MD. Record all meter readings around the circuit. 6) Go to the PSS. Synchronize manually the Generator 1 to the Grid as described in Section 5 of the PSS User Guide. 7) Readjust the excitation to give 220 V on meter MD. Record all meter readings around the circuit. Page 55

60 8) Open CB28 and close CB33 (this reduces the resistive load to 25%). Readjust the excitation to give 220 V on meter MD. Record all meter readings around the circuit. 9) Close CB28 and leave CB33 closed (this increases the resistive load to 75%). Readjust the excitation to give 220 V on meter MD. Record all meter readings around the circuit. 10) Open CB33 (resets the resistive load to 50%). Readjust the excitation to give 220 V on meter MD. 11) Close CB32 (this gives 50% resistive and 25% inductive load). Readjust the excitation to give 220 V on meter MD. Record all meter readings around the circuit. 12) Open CB32 and close CB29 (this gives 50% resistive and 50% inductive load). Readjust the excitation to give 220 V on meter MD. Record all meter readings around the circuit. 13) Close CB32, leave CB28 and 29 closed (this gives 75% resistive and 75% inductive load). Carefully monitor the excitation current as you try to get 220 V at meter MD. Never exceed the maximum rated excitation current. Note: Due to tolerances in the generator and other parts of the PSS, you may not be able to achieve the 220 V output with 75% loads. 14) Reduce the load and excitation. Break the synchronisation as shown in the PSS User Guide. Page 56

61 Experiment 8a: Symmetrical Faults - Unloaded System Procedure 1) With the PSS switched off and all CBs open, connect the circuit as shown in Figure 72. Switch on the PSS. Connect a three-phase fault application via the Fault CB at TP20. See Section 4.5 of the PSS User Guide. 2) Start up the S10 on the PC and access the Unloaded System Experiment Screen as shown in Figure 43. Select TP20 and PH-PH-PH Fault from the drop-down menu. Figure 43 Unloaded System Experiment Screen 3) On the Experiment Screen, close all CBs. 4) Go to the Control Panel. Check voltages at meters MB and MM. 5) Apply the fault at TP20 by clicking the 'Timed Fault' CB on the Control Panel. The Alarm will go on the Screen (top left corner). Click on it to cancel. 6) Go to the Disturbance Records for the RD1B relay and monitor fault current traces. 7) Repeat the experiment at other Test Points. 8) At the end of the experiment open CB2 and switch off the PSS. Page 57

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63 Experiment 8b: Symmetrical Faults - Loaded Systems Procedure 1) With the PSS switched off and all CBs open, connect the circuit as shown in Figure 73. Connect a three phase fault application via the Timed Fault Switch at TP13. See Section 4.5 of the PSS User Guide. 1) Close the two manual switches on the Double Busbar as shown in Figure 73. Set the resistive load R2 to 50% and R3 to 25%. Set all other loads to zero. Switch on the PSS. Set the fault timer to 250 ms and press Bus A (zone1) and Bus B (zone 2) blocking switches. 2) Start up the S10 on the PC and access the Loaded System Experiment Screen as shown in Figure 44. Figure 44 Loaded System Experiment Screen 3) On the Experiment Screen, close CBs 2, 3, 12, 14, 20, 23 and 25. 4) Close CB33 (to give a load of 25%). 5) On the Experiment Screen, activate the Timed Fault Switch. Look at the System Screen for the RDP- P442 relay. In the area marked Disturbance note that the disturbance record extraction has started. 6) Return to the Experiment Screen. Open CB33 and close CB28 (to give a resistive load of 50%). Activate the timed fault switch again. 7) Open CB28 (to give zero load) and activate the timed fault switch again. 8) Wait for the disturbance extraction to finish, then click on the Software tab and then click the WinAnalyse button (you must be logged in correctly for this to work). Use the WinAnalyse software to view your disturbance records. 9) At the end of the experiment reduce the load to minimum and open CB2. Switch off the PSS. Page 59

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65 Experiment 8c: Symmetrical Fault - IM Contribution Procedure 1) With the PSS switched off and all CBs open, connect the circuit as shown in Figure 74. Switch on the PSS. Connect a three-phase fault application via the fault CB at TP23. See Section 4.5 of the PSS User Guide. Connect the oscilloscope to the PSS to obtain a current trace for a fault at TP23. 2) Start up the S10 on the PC and access the IM Contribution Experiment Screen as shown in Figure 45. Select TP23 and PH-PH-PH Fault from the drop-down menu. Figure 45 IM Contribution Experiment Screen 3) On the PC Experiment Screen close all CBs, except CB34, for experiment 'IM Contribution. 4) Check voltages at meters MP and MM. Apply a three-phase fault at TP23 by clicking on the Timed Fault CB button. Cancel the Alarm, to do this: Click on the Accept button (the sounder will stop and the trip lamp wil change from flashing to steady). Click Reset (the trip lamp will go out). 5) On the Experiment Screen, click on the Software tab, then the Oscilloscope software. Use the oscilloscope software to capture the oscilloscope display. Go back to the Experiment Screen and click on the Software tab to access the WinAnalyse software. Use the WinAnalyse software to monitor the disturbance records for the RD2B relay. 6) Reclose any CBs opened during the fault. 7) On the Experiment Screen, close CB34 to start Dynamic Load. Use the raise or lower buttons to increase or decrease the load. Monitor the readings on meter MP. 8) Re-apply the fault at TP23 and repeat step 5. Compare the results. 9) At the end of the experiment, open CB34, then CB2. Switch off the PSS. Page 61

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67 Experiment 8d: Symmetrical Faults - 4 Bus System Procedure 1) With the PSS switched off and all CBs open, connect the circuit as shown in Figure 75. Manually close the upper switches on the Double Busbar System. Connect a three-phase fault application via the Fault CB at TP17. See Section 4.5 of the PSS User Guide. Set the speed/power controls of the generator to zero. Switch on the PSS. 2) Start the S10 program on the PC and access the 4 Bus System Experiment Screen, as shown in Figure 46. Figure 46 4 Bus System Experiment Screen 3) Close all CBs except CB8 in the '4 Bus System' Experiment Screen. 4) Go to the Control Panel Screen on the PC. Generator speed and field quantities can be controlled from the Generator Control Panel. Lower the Speed/power and Excitation controls to their minimum values. Start the generator. Increase the speed to 1500 rev.min -1 (50 Hz PSS) or 1800 rev.min -1 (60 Hz PSS). Close the Field CB and increase the excitation to obtain 220 V on meter MD. 5) Synchronize manually, via CB8, the Generator 1 to the Grid as described in Section 5 of the PSS User Guide. Increase the power output of Generator 1 to a low, steady value. Check the voltages and currents on meters ME to MK on the Double Busbar and record them. 6) Apply a three-phase fault at TP17 by clicking on the 'Timed Fault CB' button. 7) Compare fault currents recorded in the Measurements 1 menu and Disturbance Records of relays RG1A, RG1B and RGTB. 8) At the end of the experiment, decrease the power output from the generator to a low value and manually open CB8. Reduce excitation to the generator and open CBF. Stop the motor. Open CB2 and switch off the PSS. Page 63

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69 Experiment 9a: Unsymmetrical Faults - I2 Measurement Procedure 1) With the PSS switched off and all CBs open, connect the circuit as shown in Figure 76. Set the resistive and inductive load pots (R2 and L2) to zero. Switch on the PSS. 2) Start the S10 program on the PC and access the I2 Measurement Experiment Screen, as shown in Figure 47. Figure 47 I2 Measurement Experiment Screen 3) Return to the Experiment Screen by the yellow return button. Close all CBs for the 'I2 Measurement' Experiment. 4) Open the Control Panel. Increase the current flowing in the red and yellow lines to 4 A by clicking on the red 'raise' lamp for Loadbank 2 (Distribution Bus 1). Use meter MM for measurements. Record the current (RMS) measured also by meter MB. 5) Click on the red RGTB button on the Experiment Circuit Screen to go to 'System RGTB' relay. In the 'Main' measurements menu find the value of I2. Compare with the calculated value. 6) At the end of the experiment reduce the load to minimum and open CB2. Switch off the PSS. Page 65

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71 Experiment 9b: Unsymmetrical Faults - Trans Line Faults Procedure 1) With the PSS switched off and all CBs open, connect the circuit as shown in Figure 76. Connect a Lineto-line fault at the Fault CB terminals. Switch on the PSS. 2) Start the S10 program on the PC and access the Trans Line Faults Experiment Screen, as shown in Figure 48. Close all CBs for the 'Trans Line Faults' experiment. Figure 48 Trans Line Faults Experiment Screen 3) Apply the fault by clicking on the 'Timed Fault CB' button. 4) Go to System-Relay RD1A from the 'Symmetrical Faults' Screen and monitor fault current magnitudes. Compare with calculations. 5) Go to Disturbance Records and monitor fault current traces. 6) Repeat the experiment for other unsymmetrical faults. 7) At the end of the experiment open CB2 on the PSS and switch off the PSS. Page 67

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73 Experiment 9c: Unsymmetrical Faults - TX Terminated Line No transient fault is applied in this experiment. The experiment is carried out under steady state conditions with a line - ground fault connected through a 9.6 Ω reactance. Procedure 1) With the PSS switched off and all CBs open, connect the circuit as shown in Figure 77. Close the three manual switches on the double bus circuit. Switch on the PSS. 2) Start the S10 program on the PC and access the TX Terminated Line Experiment Screen, as shown in Figure 49. Figure 49 TX Terminated Line Experiment Screen 3) Go to the Experiment Screen. Close all CBs for the 'TX Terminated Line' experiment. 4) Go to the Measures Screen and record the currents per phase or line in meters ME, MF, MG, and MH, MJ, MK. Compare the recorded currents with those calculated by symmetrical component analysis. 5) At the end of the experiment open CB2 on the PSS and switch off the PSS. Page 69

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75 Experiment 9d: Unsymmetrical Faults - Double End Feed Procedure 1) With the PSS switched off and all CBs open, connect the circuit as shown in Figure 78. Connect Terminal S38 to the Timer CB in series with the Fault CB. Connect a Line-Line-Ground fault at the Timed Fault CB terminals. Set to zero the speed/power, excitation and load controls for the generator. Switch on the PSS. 2) Start the S10 program on the PC and access the Double End Feed Experiment Screen, as shown in Figure 50. Figure 50 Double End Feed Experiment Screen 3) On the Experiment Screen close all CBs for the 'Double End Feed' experiment, except for CB8. 4) Go to the Control Panel. Generator speed, and field quantities can be controlled from the Generator Control Panel. Start the generator. Increase the speed to 1500 rev.min -1 (50 Hz PSS) or 1800 rev.min -1 (60 Hz PSS). Close the Field CB and increase the excitation to obtain 220 V on meter MD. 5) Synchronize manually the Generator 1 to the Grid as described in Section 5 of the PSS User Guide. 6) On the Experiment Screen, increase the load at the Generator Bus (Loadbank 1) to, say, 0.5 kw. Go to the 'Measures' Screen to check, and record the currents, voltages and powers on meters MB and MD. 7) Apply the L-L-G fault by clicking on the 'Timed Fault CB' button. 8) Go to System-Relays RGTB, RGT, RG1B, and RGT to obtain fault records. Compare with calculations. 9) Go to Disturbance Records and monitor fault current traces. 10) At the end of the experiment reduce the load on the Generator to a minimum, manually open CB8 on the PSS and switch off the Generator and the PSS. Page 71

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77 Experiment 12: OC Protection - Relay Grading Procedure: Part 1 1) Check that the PSS is switched off and all CBs are open. Connect the circuit as shown in Figure 79. Connect the 'Timed Fault CB' at test point TP20. Switch on the PSS. Set the fault timer to, say, 1.0 second. 2) Start up the S10 on the PC and access the Relay Grading Experiment from the drop-down menu on the Site Screen. See Figure 51. Figure 51 Relay Grading Experiment Screen 3) Select TP20 and a three phase fault (PH-PH-PH) from the drop- down menus. 4) On the Experiment Screen close CBs for the 'Relay Grading' Experiment. 5) Check voltages on meters MB and MM. 6) Apply the fault by clicking on the 'Timed Fault CB' button. The Alarm will be activated on the top bar of the Screen. Click on it to cancel. Monitor the top bar listing of Alarms showing RD1B trip. 7) Go to the 'Alarms' tab on the bottom bar. Monitor the complete alarm record. This is optional. 8) Click on the 'Overview' tab to return to the Relay Grading Screen. 9) Click on the 'RD1B' button to go to the Trend and/or the RD1B System Screen. Monitor current magnitudes. Acknowledge the alarms and reset the relay. 10) Go to the Disturbance Records and monitor fault current traces. 11) Go to the SOE tab on the bottom bar and access the sequence of events (SOE). Procedure: Part 2 12) Open the 'Timed Fault CB' on the Control Panel. Inhibit the operation of RD1B. 13) On the Experiment Screen close the CBs. Page 73

78 14) Go to the Control Panel. Monitor voltages on meters MB and MM. 15) Apply the fault by clicking on the 'Timed Fault CB' on the Fault Panel. 16) Cancel the Alarm and monitor the listing of alarms on the top bar. It should show that RD1A has tripped. 17) Click on the 'Overview' tab to return to the Relay Grading Screen. 18) Click on the 'RD1A' button to go to the RD1A System Screen. Monitor current magnitudes. Acknowledge the alarms and reset the relay. 19) Go to the Disturbance Records and monitor fault current traces. Return to the Experiment Screen. 20) Go to the SOE tab on the bottom bar and access the sequence of events (SOE). Procedure: Part 3 21) Repeat steps 13 to 17 with both RD1A and RD1B inhibited. Relay RGTB should operate. Procedure: Part 4 22) Open the 'Timed Fault CB' and CB2. Apply a three-phase fault at TP17 through the 'Timed Fault CB'. Inhibit the Inst. O/R on Relay RD1A. 23) Repeat steps 4 to 10. RD1A should trip in a shorter time than in Part 2. Earth Faults 24) Open the 'Timed Fault CB' and CB2. 25) Apply a phase-to-earth fault at Test point TP20 by connecting a 'Timed Fault CB' terminal to earth through the 3.2Ω reactance on the PSS. 26) Now repeat steps 4 to ) Repeat steps in Part 2, Part 3 and Part 4 above with the phase-to-earth fault. Page 74

79 Experiment 13: Symmetrical Faults - Auto-reclose. In this Experiment the opening and closing of the CB23 is automatic after the fault is applied. Indication of relay operation is by the LEDs on the relay themselves or by examining the Sequence of Events and Disturbance Records for SCADA operation. The settings for the Auto-reclose Experiment are given in the PSS User Guide. Procedure 1) With the PSS switched off and all CBs open, connect the circuit as shown in Figure 80. Connect the Timed Fault CB at test point TP23. Apply a three phase fault at the fault CB terminals. Switch on the PSS. Set the timer to 20s. Press the Autoreclose button on relay RD2B. 2) Start up the S10 on the PC and access the Auto-reclose Experiment as shown in Figure 52. Figure 52 Auto-reclose Experiment Screen 3) Select a three-phase fault from the drop-down menu. 4) On the Experiment Screen close CBs for the 'Autoreclose' Experiment. 5) Check voltages on meters MB and MM. 6) Apply the fault by clicking on the Timed Fault CB button. Monitor the autoreclose process on the Experiment Screen. 7) Go to the 'Alarms' tab on the bottom bar. Monitor the complete alarm record. This is optional. 8) Click on the 'Overview' tab to return to the Auto-Reclose Screen. 9) Click on the red 'RD2B' button to go to the Trend and/or the RD2B System Screen. Monitor current magnitudes. Acknowledge the alarms and reset the relay. 10) Go to the Disturbance Records and monitor fault current traces. Return to the Experiment Screen. 11) Go to the SOE tab on the bottom bar and access the Sequence of Events. Page 75

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81 Experiment 14: Symmetrical Faults - Inst. High Set For this experiment, the operating time measured by relay RD1A is to be compared for faults at TP20 and TP17. Procedure: Part 1 (Fault at TP20 with relay RD1B inhibited) 1) Check that the PSS is switched off and all CBs are open. Connect the circuit as shown in Figure 79. Inhibit relay RD1B. Connect the Timed Fault CB at test point TP20. Switch on the PSS. Set the timer to, say, 1 second. Apply a three-phase fault at the fault CB terminals. 2) Start up the S10 on the PC and access the Inst High Set Experiment as shown in Figure 53. Figure 53 Inst High Set Experiment Screen 3) Select TP20 and a three-phase fault (PH-PH-PH) from the drop- down menus. 4) On the Experiment Panel close all CBs for the 'Inst High Set' Experiment. 5) Go to the Control Panel by clicking on the 'Control Panel' Button. Check voltages on meters MB and MM. 6) Apply the fault at TP20 by clicking on the 'Timed Fault CB' button. The Alarm will be activated on the top bar of the Screen. Click on it to cancel. Monitor the top bar listing of Alarms showing RD1A trip. 7) Go to the 'Alarms' tab on the bottom bar. Monitor the complete alarm record. This is optional. 8) Click on the 'Overview' tab to return to the Relay High Set Screen. 9) Click on the 'RD1A' button to go to the Trends and/or the RD1A System Screen. Monitor current magnitudes. Acknowledge the alarms to reset the relay. 10) Go to the Disturbance Records and monitor fault current traces and fault times. Return to the Experiment Screen. Page 77

82 Procedure: Part 2 (Fault at TP17) 11) Switch off the PSS. Connect the 'Timed Fault CB' at test point TP17 and connect a three-phase fault at the fault CB terminals. Switch on the PSS. 12) On the Experiment Screen close the CBs for the Instantaneous High Set Experiment. 13) Go to the Control Panel by clicking on the 'Control Panel' Button. Check voltages on meters MB and MM. 14) Apply the fault at TP17 by clicking on the 'Timed Fault CB' button. The Alarm will be activated on the top bar of the Screen. Click on it to cancel. Monitor the top bar listing of Alarms showing RD1A trip. 15) Go to the 'Alarms' tab on the bottom bar. Monitor the complete alarm record. This is optional. 16) Click on the 'Overview' tab to return to the Relay High Set Screen. 17) Click on the 'RD1A' button to go to the RD1A System Screen. Monitor current magnitudes. Acknowledge the alarms to reset the relay. 18) Go to the Disturbance Records and monitor fault current traces and fault times. Return to the Experiment Screen. Page 78

83 Experiment 15: Over Current Protection - Back Trip Procedure 1) Check that the PSS is switched off and all CBs are open. Connect the circuit as shown in Figure 79. 2) Connect the 'Timed Fault CB' at test point TP20. Connect a three-phase fault at the fault CB terminals. Switch on the PSS. Set the fault timer to, say, 1.0 second. Press the IMDT Override and Enable Back Trip buttons on the relay RD1B. 3) Start up the S10 on the PC and access the Back Trip Experiment as shown in Figure 54. Figure 54 Back Trip Experiment Screen 4) Select a three-phase fault (PH-PH-PH) from the drop- down menus. 5) On the Experiment Screen close all CBs for the 'Back-Trip' Experiment. 6) Go to the Control Panel by clicking on the 'Control Panel' Button. Check voltages on meters MB and MM. 7) Apply the fault by clicking on the 'Timed Fault CB' button. The Alarm will be activated on the top bar of the Screen. Click on it to cancel. Monitor the top bar listing of Alarms for RB1B and showing RD1A trip. 8) Go to the 'Alarms' tab on the bottom bar. Monitor the complete alarm record. This is optional. 9) Click on the 'Overview' tab to return to the Back Trip Screen. 10) Click on the 'RD1B' button to go to the RD1B System Screen. Monitor current magnitudes. Repeat for the relay RD1A. Acknowledge the alarms and reset the relays. 11) Go to the Disturbance Records and monitor fault current traces. Return to the Experiment Screen. 12) Go to the SOE tab on the bottom bar and access the Sequence of Events. Page 79

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85 Experiment 16: Over Current Protection - Directional Control (and TX) Procedure A - Directional Control 1) Check that the PSS is switched off and all CBs are open. Connect the circuit as shown in Figure 81. Connect the 'Timed Fault CB' at connector S58. Connect a three-phase fault at the fault CB terminals. Switch on the PSS. Set the timer to, say, 1.5 s. Check within the OC Protection Menus of relays RD1A and RD2A that I>1 Direction is set to Directional Reverse and the Characteristic Angle is set to 30. 2) Start up the S10 on the PC and access the Directional Control Experiment as shown in Figure 55. Figure 55 Directional Control Experiment Screen 3) Select a three phase fault (PH-PH-PH) from the drop-down menu. 4) On the Experiment Screen, close the CBs for the 'Directional Control' Experiment. 5) Check voltages on meters MB and MM. 6) Apply the fault by clicking on the 'Timed Fault CB' terminals. The Alarm will be activated on the top bar of the Screen. Click on it to cancel. Monitor the top bar listing of Alarms, which should show that RD2A operated, but RD1A did not operate. 7) Go to the 'Alarms' tab on the bottom bar. Monitor the complete alarm record. This is optional. 8) Click on the 'Overview' tab to return to the Directional Control Experiment Screen. 9) Click on the 'RD2A' button to go to the Trend and/or the RD2A System Screen. Monitor current magnitudes. Acknowledge the alarms and reset the relay. 10) Go to the Disturbance Records and monitor fault current traces. Return to the Experiment Screen. Procedure B - Directional Control Transformers (TX) Refer to the PSS manual for details of this experiment. Page 81

86 Figure 56 Directional Control TX Experiment Screen Page 82

87 Experiment 17: Distance Protection This experiment has different circuits for phase faults and earth faults. Additional connections are made for earth faults to simulate the impedance of the earth path to zero-sequence currents. The additional connections are not shown on screen. Procedure: Part 1 - Phase Faults. 1) Check that the PSS is switched off and all CBs are open. Connect the circuit as shown in Figure 82. Connect a three-phase fault at the Fault CB terminals. Connect the Timed Fault CB at test point TP6. Switch on the PSS. Set the fault timer to, say, 1.0 second. 2) Start the S10 Program on the PC and access the Distance Protection Experiment Screen as shown in Figure 57. Figure 57 Distance Protection Experiment Screen 3) Select Test Point TP6 and a three phase fault (PH-PH-PH) from the drop-down menus at the top of the Screen. 4) On the Experiment Screen close CBs for the 'Distance Protection' Experiment. 5) Check voltages on meters MB and MM. 6) Apply the fault by clicking on the 'Timed Fault CB' button. The Alarm will be activated on the top bar of the Screen. Click on it to cancel. Monitor the top bar listing of Alarms, which should show that relay RDP operated. 7) Go to the 'Alarms' tab on the bottom bar. Monitor the complete alarm record. This is optional. 8) Return to the Distance Protection Experiment Screen. 9) Click on the red RDP button to access 'System RDP, the P442 Distance Relay. 10) Click on the 'Main' button on the right hand panel to obtain a list of currents, voltages and, in addition, 'Fault Location, 'Faulted Phases' and 'Fault Zone'. Acknowledge the alarms and reset the relay. 11) Go to the Disturbance Records and monitor fault current traces. Return to the Experiment Screen. Page 83

88 12) Now return to the PSS. Open CB2. Apply the fault at TP7 and repeat the procedure given above in items 2 to ) Repeat the procedure again for a fault at TP8. Procedure: Part 2 - Earth Faults Open CB2 on the PSS. Connect Line 1 at TP7 between one line and earth via the Timed Fault CB. Repeat the experiment procedure for Phase Faults above. The relay RDP should indicate a L-G fault 100 km down the line. Page 84

89 Experiment 18: Grid Transformer Protection and REF Protection The Grid Transformer has several protection elements: Primary Overcurrent, Differential, Restricted Earth Protection and Stand-by O/C Protection on the earth connection of the secondary star-winding. These are indicated individually on the Experiment Screen for Grid Tx Protection. Two test points are shown: TP2 and TP1. Faults at TP2 should trip RGTB (Relay P122) and the primary overcurrent protection of RGT. The Grid Transformer protection should be stable for through faults. Faults at TP1 should operate the main Differential Protection. If it does not operate, the restricted earth fault protection, REF2, should operate for earth faults and the primary overcurrent for earth and line faults. The Standby Earth fault protection is the last line of protection for earth faults; this has an IDMT overcurrent element with a long operating time. There are two test points not shown on the Experiment Screen, TPA and TPB. These are test points on one phase of the secondary star winding. Line-ground faults should be applied at these points to assess the relative sensitivity of the restricted earth fault protection. See the PSS User Guide. Use a 9.6 Ω inductor in all full-voltage line applications to limit the fault current. Connect the reactance between either two lines or a line and earth. Never apply a Phase-Phase-Earth fault. For earth faults at TPA or TPB, connect one of the resistors supplied between the test points and earth, not the 9.6 Ω inductor. Do not block RGT Overcurrent as RGT Overcurrent acts as a backup to the Differential Protection. Page 85

90 Procedure A - Grid Transformer Protection 1) Check that the PSS is switched off and all CBs are open. Connect the circuit as shown in Figure 83. Connect the Timed Fault CB at test point TP20. Apply a line-line fault at the Fault CB terminals. Switch on the PSS. Set the timer to, say, 0.50 second. 2) Start up the S10 on the PC and access the Grid TX Prot Experiment Screen from the drop-down menu on the Site Screen. See Figure 58. Figure 58 Grid Protection Experiment Screen 3) Select test point TP2 and a line-line fault (PH-PH) from the drop-down menus. 4) On the Experiment Screen close CBs for the 'Grid TX Protection' Experiment. 5) Go to the Control Panel by clicking on the 'Control Panel' Button. Check voltages on meter MB and MA. 6) Apply the fault by clicking on the 'Timed Fault CB' button on the Fault Panel. The Alarm will be activated on the top bar of the Screen. Click on it to cancel. Monitor the top bar listing of Alarms. 7) Go to the 'Alarms' tab on the bottom bar. Monitor the complete alarm record. This is optional. 8) Return to the 'Grid TX Protection' Screen by clicking on the Overview tab. Click on the 'RDTB' button to go to the RDTB System Screen. 9) Click on the 'Measures' button at the top right of the screen. See Figure 58. Currents in each phase of the primary and secondary of the transformer are shown as well as INb (vector sum of phase currents) and IYb (measured). The main DIFF and DIFF RESTRAIN currents are shown, the latter current being proportional to the through fault current. Similar values are given for the Restricted Earth Protection on the secondary star winding, REF2 DIFF current and REF2 RESTRAIN current. 10) Up to nine Current Alarms are shown on the 'System RGT' Screen. Acknowledge the Alarms and reset the relay. 11) As there are several protection elements likely to operate for faults at TP1, look at the SOE (tab on the bottom bar). 12) Return to the Experiment Screen. No route to Disturbance Records is provided on the Experiment Screen, but these should also be looked at via the 'Tools' or 'Software' tab on the bottom bar. Page 86

91 13) The experiment should be repeated for line-ground faults at both TP1 and TP2, and at TPA and TPB. 14) Various values of earthing resistor should be connected at the star point of the secondary winding for faults at TPA and TPB. Refer to the PSS User Guide for more detailed information and procedure. Procedure B - Grid TX REF Protection Refer to the PSS manual for details of this experiment. Figure 59 Grid Transformer ref Protection Experiment Screen Page 87

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93 Experiment 19: Busbar Protection Suggested Procedure 1) Check that the PSS is switched off and all CBs are open. Connect the circuit as shown in Figure 84. Connect the Fault CB in series with the 'Timed Fault CB' at test point TP13. Apply a three-phase fault at the fault CB terminals. Switch on the PSS. Set the timer to, say, 1.0 seconds. 2) Start up the S10 on the PC and access the Busbar Prot n Experiment Screen as shown in Figure 60. Close the two manual switches highlighted in green. Figure 60 Busbar Protection Experiment Screen 3) Select test point TP13 and a three-phase fault (PH-PH-PH) from the drop- down menus. 4) On the Experiment Screen close the CBs for the 'Busbar Prot'n' Experiment. 5) Check voltages on meters ME and MK. 6) Apply the fault by clicking on the 'Timed Fault CB' button. The Alarm will be activated on the 7) top bar of the Screen. Click on it to cancel. Monitor the top bar listing of Alarms showing RDBZ1 and RDBZ2 trip. 8) Go to the 'Alarms' tab on the bottom bar. Monitor the complete alarm record. This is optional. 9) Return to the 'Busbar Prot'n' Screen by clicking on the Overview tab. 10) Click on the 'RDZB' button to go to the RDZB System Screen. Monitor current magnitudes. Acknowledge the alarms and reset the relay. 11) Go to the Disturbance Records and monitor fault current traces. Return to the Experiment Screen. 12) Repeat the Experiment for faults, line or earth faults, at TP14 and TP17. Page 89

94 Notes The alarms are the main source of information in this Experiment, but as usual, values of currents can be seen in the Main menu of the P142 relays, or in Disturbance records. Monitor from the Alarms on the top bar of the Screen the relay(s) that have tripped, RDZ1 or RDZ2, or both. For tests at TP17, relay RD1A should trip, but not the busbar protection. If RD1A is blocked, RGTB should operate. For tests at TP16, relay RGTB, and maybe RGT (Overcurrent) should start or operate. For faults at TR13, relays RDBZ1 and RDBZ2 should operate. For faults at TP14, relay RDZ2 only should operate. See the PSS User Guide. Page 90

95 Experiment 20: Generator Protection The Generator protection contains several individual elements. The main elements are Differential, Overcurrent and Earth Fault Protection. All elements are shown on the Generator Protection Experiment Screen. Refer to the PSS User Guide for information on individual protection applications. Two test points are shown on the diagram in Figure 85, TP3 and TP4. These test points can be used for investigating the differential protection of generator G1 for phase and earth faults. TP4 should be used to test the overcurrent protection. Initially, at least, faults should be applied using the 9.6 Ω inductor in the central control centre to limit the fault current for line-line faults and line-earth faults. Also, initially, reduce the voltage generated by reducing the excitation of the generator. The generator should not be loaded for these tests. The System Back-up protection can be tested for faults further out on the system. TP58 can be used to apply system faults. It may be necessary to insert a short line in TP3. Refer to the PSS User Guide for more detailed information. Measure the voltage at the relay for system faults and compare with the voltage setting of the relay (160 V primary). For the Negative Sequence relay it is suggested that it's operation is investigated by connecting a small load across two lines at TP58. Measure the I1 and I2 components of current at relay RG1B. The relay should alarm after a set time and trip after a much longer time. Refer to the PSS User Guide for more detailed information. It will be found that if the voltage setting for 100%St EF VN3H>, in the 100% Stator EF protection, is lowered below 10.0 V, the protection will trip due to third harmonic voltages under normal running and load conditions. Suggested Procedure 1) Check that the PSS is switched off and all CBs are open. Connect the circuit as shown in Figure 85. Connect the 'Timed Fault CB' at test point TP3. Connect a line-to-line fault through the 9.6Ω inductor at the Fault CB terminals. Switch on the PSS. Set the fault timer to, say, 1.0 second. 2) Start up the S10 on the PC and access the Generator Prot n Experiment Screen as shown in Figure 61. Figure 61 Generator Protection Experiment Screen 3) Go to the Experiment Screen and close all CBs for the Generator Prot'n Experiment. Page 91

96 4) Go to the Generator Control Panel. Generator speed, and field quantities can be controlled from the Generator Control Panel. Check that the Generator speed and excitation raise/lower controls are at their minimum positions. Check on the PSS that the Field CB is open. 5) Start the Generator. Set the Generator speed at 1500 rev.min -1 (50 Hz PSS) or 1800 rev.min -1 (60 Hz PSS). Close the Field CB. Raise the output voltage measured on meter MD to 160 V line. 6) Return to the Experiment Screen and click on the meter MC. Monitor the system voltages. 7) Select test point TP3 and a phase-phase fault (PH-PH) from the drop-down menus. 8) Check voltages on meters ME and MK. 9) Apply the fault by clicking on the 'Timed Fault CB' button. The Differential and, maybe, the Overcurrent Protection should trip. The Alarm will be activated on the top bar of the Screen. Click on it to cancel. 10) Only three current alarms are shown on the top bar. A full listing can be obtained from the Alarm Screen (bottom tool bar). 11) Return to the Experiment Screen and access the relay RG1 System Screen. The buttons at the top right hand corner of the RG1 System Screen can access the 'Measures' Screens. The important Screens are 'Main', 'Other Currents' and 'Other Voltages'. The P343 Relay provides most of the values required. See Table 4. For transient values of currents the Disturbance Records should be accessed. 12) Repeat the above procedure for faults at other Test Points for testing other protection functions as described in the PSS User Guide Page 92

97 5.3 Second Generator Experiments These Experiments are for the combined system of Power System Simulator (PSS) and the Second Generator Unit (SGU). As you do these experiments, use the both the PSS and SGU User Guides with the SCADA User Guide. For clarity, the relevant connection diagrams are also provided in APPENDIX 3 of this User Guide. Page 93

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99 Experiment 23: Generators in Parallel, Connected to the Grid Procedure 1) With the PSS switched off, connect the circuit on the PSS and the Second Generator Unit (SGU) as shown in Figure 86 in APPENDIX 3 of this Manual. Make sure the two-way switch on the SGU is switched to 'Central Generator' and the field excitation is switched to 'Manual Excitation'. On the G2 Prime Mover control Panel select 'REMOTE'. Switch on the PSS and the SGU. 2) Start up the S10 on the PC and access the '2 GENERATOR SYSTEM-HV' Screen, as shown in Figure 62. Figure 62 Two Generator System HV Experiment Screen 3) On the Experiment Screen close CB6, CB4, CB3 and CB5, and CB2 but not CB36 or CB8. Check the field breakers, CBF and CBF2 are open. 4) Go to the top tool bar on the Experiment Screen and click on the Central Generator Control Panel button. Start the generator. Increase the speed to 1500 rev.min -1 (50 Hz PSS) or 1800 rev.min -1 (60 Hz PSS). Close the Field CBF and increase the excitation to obtain 220 V. 5) Go to the PSS. Synchronize the Central Generator to the Grid by manually closing CB8, as described in Experiment 1 of the PSS Manual. 6) On the PC Screen, click on the Second Generator Control Panel button. Generator speed, and field quantities can be controlled from the Second Generator Control Panel. Start the generator. Increase the speed to 1500 rev.min -1 (50 Hz PSS) or 1800 rev.min -1 (60 Hz PSS). Close the Field CBF2 and increase the excitation to obtain 220 V. 7) Go to the PSS. Using the Remote Control Panel for the Second Generator, synchronize Generator 2 to the Grid by manually closing CB36, as described in Section 5.1, page 23 of the SGU Manual. Both Generators are now 'floating' on the Grid Busbars. 8) Using the appropriate Control Panels on the Experiment Screen, set the Second Generator to generate 0.5 kvar and 0.5 kw. And set the Central Generator to generate 0.5 kvar. 9) Vary the power supplied by the Central Generator from 0.5 kw to 2 kw. Note the effect on the Second Generator supply and the total supply to the Grid. 10) Vary the reactive power from the Central Generator from 0.5 kvar to 2 kvar. Note the effect on supply from the Second Generator and total supply to the Grid. Page 95

100 11) At the end of the experiment decrease the power output from the generators to a low value and manually open CB36. Reduce the excitation of the generator and open CBF2 manually. Stop the motor, either remotely or at the PSS. Page 96

101 Experiment 24: Second Generator Automatic Control - VAr Control Procedure 1) With the PSS switched off, connect the circuit on the PSS and the Second Generator Unit (SGU) as shown in Figure 87 in APPENDIX 3 of this Manual. Make sure the two-way switch on the SGU is switched to 'Central Generator' and the field excitation is switched to 'AVR Excitation'. On the G2 Prime Mover Control Panel select 'REMOTE'. Switch on the PSS and the SGU. 2) Start up the S10 on the PC and access the 'GEN 2 SYNC TO MAINS- AVR excite' Experiment Screen, as shown in Figure 63. Figure 63 Gen 2 Sync to Mains AVR Excite Experiment Screen 3) On the Experiment Screen, Figure 63, close CB4 and CB2, but not CB36. 4) Go to the PSS. On the G2 Remote Control Panel, start the Second Generator. Increase the speed to 1500 rev.min -1 (50 Hz PSS) or 1800 rev.min -1 (60 Hz PSS). 5) Go to the Automatic Voltage Regulator (AVR) on the Second Generator Unit and switch on the 'VOLTS' and 'VAr' control. Switch off the 'COSφ' control. Return to the Experiment Screen. Close the Field breaker CBF2. Adjust/increase the AVR 'VOLTS' control to obtain a terminal voltage of 220 V at meter MT (on screen). 6) Go to the PSS. Synchronize the Second Generator to the Grid, by manually closing CB36, as described in the SGU Manual. When the Second Generator is synchronized, the AVR automatically switches to the VAr control and regulates the generator terminal voltage to match the mains voltage. Return to the Experiment Screen. Monitor the Generator field excitation voltage and current, terminal voltage, line current and the speed. 7) Monitor the line current of the generator, Ia, and the power factor, on screen and on meter MT. 8) Using the VAr control buttons, set the reactive power output (exporting) to 1.0 kvar. Note the change in on Screen values of generator output current and VArs, the generator voltage and the field current and voltage. 9) Increase the power from zero to 2.0 kw in steps of 0.5 kw by using the 'speed' control buttons on Screen (just above generator symbol). At each step record the power (kw), reactive power (VAr) and power factor (cosφ). Page 97

102 10) Create a power chart and plot on the chart the locus of the readings obtained. Repeat for other values of VAr, both leading (imported) and lagging (exported). 11) At the end of the experiment decrease the power output from the generator to a low value by means of the on Screen speed control button, and manually open CB36. Reduce the excitation of the generator and open CBF2 manually. Stop the motor, either remotely or at the PSS. Page 98

103 Experiment 25: Second Generator Automatic Control - Power Factor (Cosφ) Control Procedure 1) With the PSS switched off, connect the circuit on the PSS and the Second Generator Unit (SGU) as shown in Figure 87 in APPENDIX 3 of this Manual. Make sure the two-way switch on the SGU is switched to 'Central Generator' and the field excitation is switched to 'AVR Excitation'. On the G2 Prime Mover Control Panel select 'REMOTE'. Switch on the PSS and the SGU. 2) Start up the S10 on the PC and access the 'GEN 2 SYNC TO MAINS - AVR excite' Experiment Screen, as shown in Figure 64. Figure 64 Gen 2 Sync to Mains AVR Excite Experiment Screen 3) On the Experiment Screen, Figure 64, close CB4 and CB2, but not CB36. 4) Go to the PSS. On the G2 Remote Control Panel, start the Second Generator. Increase the speed to 1500 rev.min -1 (50 Hz PSS) or 1800 rev.min -1 (60 Hz PSS). 5) Go to the Automatic Voltage Regulator (AVR) on the Second Generator Unit and switch on the 'VOLTS' and 'COSφ' control. Switch off the VAr control. 6) Return to the Experiment Screen. Close the Field breaker CBF2. Adjust/increase the AVR 'VOLTS' control to obtain a terminal voltage of 220 V at meter MT (on screen). 7) Go to the PSS. Synchronize the Second Generator to the Grid, by manually closing CB36, as described in the SGU Manual. When the Second Generator is synchronized, the AVR automatically switches to the COSf control and regulates the generator terminal voltage to match the mains voltage. 8) Return to the Experiment Screen. Monitor the Generator field excitation voltage and current, terminal voltage, line current and the speed. 9) Monitor the line current of the generator, Ia, and the power factor, on screen and on meters MT. 10) Using the 'COSφ' control buttons, set the power factor to 0.85 lagging. Note the change in on Screen values of generator output current and VArs, the generator voltage and the field current and voltage. 11) Increase the power from zero to 2 kw in steps of 0.5 kw by using the 'speed' control buttons on Screen (just above generator symbol). At each step, record the power (kw), reactive power (kvar) and power factor (cosφ). Page 99

104 12) Create a power chart and plot on the chart the locus of the readings obtained. Repeat for other values of COSφ. 13) At the end of the experiment decrease the power output from the generator to a low value by means of the on-screen speed control button, and manually open CB36. Reduce the excitation of the generator and open CBF2 manually. Stop the motor, either remotely or at the PSS. Page 100

105 Experiment 26: Second Generator as an Embedded Generator - P & Q Flow in a Distribution System This Experiment is described in the Second Generator Manual. As the circuit is not immediately identifiable from the Connection Diagram in the Appendix of this Manual, the circuit diagram is reproduced here in Figure 65. Note that a number of power distribution and system control scenarios can be investigated on this circuit, including the use of the tap-changer on Transformer DTX3. Figure 65 Circuit Diagram for Embedded Second Generator Procedure 1) With the PSS switched off, connect the circuit on the PSS and the Second Generator Unit (SGU) as shown in Figure 88 in APPENDIX 3 of this Manual. Make sure the two-way switch on the SGU is switched to 'Embedded Generator', CB27 on the Utilization Bus is open, and the field excitation is switched to 'Manual Excitation'. Switch on the PSS and the SGU. 2) Start up the S10 on the PC and access the 'P & Q FLOW IN DIST. SYS' Experiment Screen, as shown in Figure 66. Note that the interconnections of the line units to the Double Bus Unit are shown in green, and the remaining connections in red. Note also that the two halves of the Utilization bus have been located separately on the Screen circuit. 3) On the Experiment Screen, close all circuit breakers around the Double Busbar Unit: CB12, CB14 and CB16, and CB18 and CB19, but not CB10 or CB15. Check that all load breakers are open: CB28, CB29, CB30 and CB31, CB32 and CB33. Check the field breaker, CBF2 is open. 4) On the Experiment Screen, close CB25, CB26, CB23, CB24 and CBs20 and 22. Close CB4, and CB2. The Grid Supply is now connected to the Double Bus Unit and the parallel line Distribution System. Monitor readings of power and reactive power around the circuit. Page 101

106 Figure 66 P&Q Flow in Dist.Sys Experiment Screen 5) Go to, and click on the PSS Control Panel on the Experiment Screen. Vary the resistance and reactance of Loads A (L2, R2) and B (L3, R3) in turn and note for each the power and reactive power flows in all branches of the circuit. Do not increase loads above 50%. 6) On the Experiment Screen click on the Second Generator Control Panel button, positioned just below the field circuit (bottom right). Generator speed and field quantities can be controlled from the Second Generator Control Panel. Start the generator. Increase the speed to 1500 rev.min -1 (50 Hz PSS) or 1800 rev.min -1 (60 Hz PSS). Close the field breaker CBF2 and increase the excitation to obtain 220 V. 7) Go to the Second Generator Unit. Using the Generator Control Panel, synchronize Generator 2 to the Utilization Bus by manually closing CB37, as described in the SGU Manual. 8) On the Experiment Screen, access the 'Gen 2 Control' and increase the power supplied by the Generator in steps until all the power to the loads is supplied only by the Generator. Note the power, reactive power and voltages around the circuit. Refer to the Second Generator Manual for further information. 9) At the end of the experiment decrease the power output from the generator to a low value and manually open CB37. Reduce the excitation of the generator and open CBF2 manually. Stop the motor, either remotely or at the PSS. Page 102