Product brochure. UniGear 550 Medium voltage, arc-proof, air-insulated, metal-clad switchgear

Transcription

1 Product brochure UniGear 550 Medium voltage, arc-proof, air-insulated, metal-clad switchgear

2 Contents Description 0 Applications Air-insulated 05 Normal service conditions 05 Standards 05 Electrical characteristics Metal-clad 0 Compartments 0 Main busbars 0 Branch connections 0 Earthing switch 0 Earthing busbar 0 Insulating bushings and shutters 0 Cables 0 Gas exhaust duct Safety 07 Interlocks 07 Padlocks 07 Locking magnets Type tests 08 Temperature rise 08 Dielectric 08 Apparatus making and breaking capacity 08 Earthing switch capacity 08 Mechanical operations Arc proof 09 Vacuum circuit-breakers-vmax 09 Insulating monobloc Vacuum circuit-breakers Vacuum circuit-breakers-vmax Insulating monobloc Operating mechanism Truck Apparatus-operator interface Standards Uses and features Block-type CTs Bushing-type current transformers Earthing switch ST-UG Feeder protection General Applications and features 5 Recommended products Transformer protection General Applications and features Motor protection 7 General 7 Applications and features 8 Recommended products Communication 9 General 9 Utility applications IEC SPA 9 LON 9 IEC DNP V.0 Industrial applications 0 Profibus DP V 0 Modbus 0 OPC Arc protection General Applications and features Recommended products Selection guide REF5plus multifunction protection and control unit Hardware Machine-user interface Central unit Communication Synchronization 5 Automatic transfer systems Typical units and technical data Single-line diagram of the typical units 7 Single-line diagram of the busbar applications 7 Graphical symbols 7 Technical data Main connection example 9 Incoming/outgoing-bottom cables Incoming/outgoing-top cables entry (depth: 50 mm) Incoming/outgoing-top busbar entry (depth: 50 mm) 5 Bus-tie Measurement 7 Measurement (VTs) 9 Bus-riser Contens I UniGear 550

3 Description The UniGear 550 can be positioned against the wall. This in turn allows all service and maintenance operations to be carried out directly from the front. Accessing the cable area is particularly convenient by simply removing the base of the circuit-breaker compartment. As a standard solution, it is possible to connect up to three singlepole cables per phase (with a maximum cross-section of 85 mm per panel up to 50 A and 500 mm per panel up to 000 A) or two cables per phase with a maximum cross section of 00 mm per panel up to 50 A and 800 mm per panel up to 000 A). The connection height of the cables in relation to the floor should be 00 mm for the panel up to 50 A and 55 mm for the 00 A and 000 A panels. As standard solution UniGear 550 uses toroidal current transformers (CTs) which are fixed onto a CT Rod". As an optional solution, the transformers can be fixed on a DIN rail. The UniGear 550 switchgear panel is the latest product to join the large family of UniGear products. UniGear 550 mirrors all the construction characteristics of other UniGear standard panels. UniGear 550 can support a maximum panel current of 000 A and it is designed to accommodate ABB Vmax/L circuit breaker. One of the most unique aspects of this panel is its size. It only measures 550 mm in width, making it a very compact and versatile product. The panel design is such that fixed voltage transformers (VTs) can be inserted into the front of the panel. The capacitive signal for indicating the voltage present is connected directly to the insulators which support the busbars on the cable side. The surge arresters can also be inserted in the cable area. The UniGear 550 switchgear is fitted with the interlocks and accessories needed to guarantee top level safety and reliability, both for the installation and the operators. It has undergone all the tests required by the international standards (IEC) and local standards (for example the GB, Chinese and Russian GOST standards). It has been built so that it can be connected directly to the UniGear standard panel. In fact, it has the same overall dimensions (height and depth) and the same omnibus busbars, allowing it to handle a maximum current value of up to 000 A. UniGear 550 I Description

4 Description Applications Business services, public and civil buildings Shopping malls Supermarkets Telecom building 0ffice buildings Banks Hospitals Sports grounds Playgrounds Residential areas Large infrastructures and civil works Food processing Textile Chemicals Pulp and paper Cement Transport Airports Ports Power systems Switching stations Light industrial applications Machinery Automotive products manufacturing Electronics Communications products processing Tobacco Wine processing Description I UniGear 550

5 Air-insulated with the following standards: IEC 7- for general purposes IEC 7-00 for the switchgear IEC 7-0 for the earthing switch IEC 007- For the insulation coordination IEC 7-00 for the circuit-breakers UnlGear 550 has been certified as having satisfied the requirements of major shipping registers (LR RINA BV and GL) for use in marine Installations. Normal service conditions The rated characteristics of the switchboard are guaranteed under the following ambient conditions: Minimum ambient temperature:-5 Maximum ambient temperature: +0 Maximum relative humidity: 95% Maximum altitude: 000 m a.s. Presence of normal, non-corrosive and uncontaminated atmosphere Standards The switchboard and main apparatus contained in it comply In accordance with the IEC 7-00 standard, UniGear 550 is defined as follows: Partition metallic (PM): This means the panel is equipped with metallic shutters and partitions between the operating parts and an open compartment Loss of service continuity (LSCB): In other words, service of the main busbar and of the cable compartment is guaranteed when normal maintenance is being carried out in one of the main circuit compartments (e.g. circuitbreaker compartment) Internal arc classified (IAC AFLR): Panels classified as IAC AFLR, have fulfilled the five criteria of the internal arc tests from the front, side and rear having fulfilling the five criteria of the internal arc tests Degrees of protection The degrees of protection of the switchgears conform with IEC 059 standards. UniGear switchboards are normally supplied with the following standard degrees of protection: IP X on the external housing IP X inside the units Color at the external surfaces: RAL 705 Electrical characteristics IEC GB GB IEC Rated voltage kv 7.5 Rated insulationvoltage kv 7.5 Rated power frequency withstand voltage kv m 8 8 Rated lightning impulse withstand voltage kv Nominal frequency Hz Rated short-time withstand current ka s ()...5 Peak curent ka Internal arc withstand current ka s Main busbars rated current () A Branch connections rated current A () Up to 000 A if coupled with other Unigear units () Panel for 00 A-000 A is tested for s UniGear 550 I Air-insulated 5

6 Metal-clad Compartments Each UniGear 550 panel consists of three power compartments: apparatus, busbars and feeder, which are segregated from each other by metallic partitions. There are two panel versions available for closing the apparatus and feeder compartment doors: one version uses screws and the other a central handle. Each unit is fitted with an auxiliary compartment where all the instruments and cabling are housed. Arc-proof switchgear is normally provided with a duct to evacuate the gases produced by an arc. All units are accessible from the front, and the maintenance and service operations can therefore also be carried out with the switchgear wall mounted. Main busbars The busbar compartment contains the main busbar system which is connected to the fixed upper isolating contacts of the apparatus by means of branch connections. The main busbars are made of electrolytic copper-flat busbars or a special copper section is used-and are normally covered with insulating material. There is a single busbar compartment along the whole length of the switchgear and this can be fitted with segregations so as to divide each unit into compartments. Branch connections The feeder compartment contains a branch system that enables a connection between the power cables and the fixed lower isolating contacts of the apparatus. The branch connections are made with flat busbars composed of electrolytic copper for the whole range of currents and are normally covered with insulating material. Earthing switch Each incoming/outgoing feeder compartment can be fi tted with an earthing switch for cable earthing. This switch can also be used to earth the busbar system (measurements and bus-tie units). The earthing switch has short-circuit making capacity. Earthing busbar The earthing busbar is made of electrolytic copper. It runs longitudinally all round of the switchgear, thereby guaranteeing maximum personnel and installation safety. Insulating bushings and shutters The insulating bushings contained in the apparatus compartment contain the fixed contacts that enable a connection between the apparatus, and the busbar and feeder compartments respectively. The bushings are of a single-pole type and made of epoxy resin. The shutters are metallic and are activated automatically as the apparatus is being moved from the rackedout position to the service position and vice versa. Cables Single and three-core cables-up to a maximum of twelve per phase-can be used depending on the rated voltage, the unit dimensions and the cable cross section. The cables are easily accessible from the front of the switchgear panel which can be wall mounted in the station. Gas exhaust duct The hot gases and incandescent particles produced by the internal arc must be evacuated from the room. Therefore, a gas exhaust duct is positioned above the switchgear, running along its entire length. Each power compartment is fitted with a flap positioned at the top. The pressure generated by the fault causes it to open, allowing the gas to pass into the duct. The UniGear 550 switchgear is equipped with a complete range of solutions to deal with all requirements, irrespective of whether evacuation is required directly at the end of the switchgear, or if solutions from the front or rear are requested. Some installations, such as those in the marine industry, do not allow the gases to be conveyed outside the room and therefore dedicated solutions have been realized using expansion chambers and longitudinal evacuation chimneys that not only guarantee personnel safety, but which conform with the relevant standards. The position of the earthing switch can be seen from the front of the switchgear by means of an indicator. Metal-clad I UniGear 550

7 Safety Padlocks The apparatus and feeder compartment doors can be locked in the closed position by means of padlocks. These can be applied to both door-closing versions, i.e. where screws are used or a central handle. The operations needed to rack the apparatus in and out, and to open and close the earthing switch can be prevented by applying the padlocks to the insertion slots of the relevant operating levers. The metallic segregation shutters can be locked by means of two independent padlocks in both the open and closed positions. The UniGear 550 switchgear is fitted with all the interlocks and accessories needed to guarantee the high level of safety and reliability needed both during installation and for the operators. Interlocks Standard safety interlocks, foreseen by the relevant standards, are necessary to guarantee the correct operation sequence. Other interlocks, available on request, must be considered in the installation, service and maintenance procedures. Their presence guarantees the highest level of reliability even when an accidental error occurs, and allows what ABB defines as an "error-free" system of interlocks. The switchgear is able to accommodate padlocks with diameters ranging from mm to 8 mm. Locking magnets The locking magnets are used to make automatic interlock logics without human intervention. The apparatus racking-in/out and the earthing switch opening/closing operations can be prevented. The doors of the apparatus and feeder compartments can be locked in the closed position. The magnets can be applied to both door closing versions. The magnets operate with active logics and therefore the lack of auxiliary voltage makes the lock become operative. UniGear 550 I UniGear 550 Safety 7

8 Type tests The UniGear switchgear has undergone all the tests required by the international (IEC) and regional standards (including the Chinese GB and Russian GOST standards). In addition, tests required by the main shipping registers (LR, DNV, RINA, BV and GL) have been carried out to ensure that the switchgear is suitable for use in marine installations. The tests simulate situations which occur very rarely or never in normal installations. For example, a short circuit at the maximum current level for which the installation has been designed is unrealistic because of the presence of currentlimiting components (such as the cables) and because the power available is normally lower than rated levels. Each switchgear unit is also subjected to routine factory tests before delivery. These functional tests check that the switchgear is configured correctly according to the specific characteristics of each installation. Typical type tests include: Short-time withstand current and peak withstand current tests Temperature rise tests and main circuit impendence measurements Dielectric test on the main and auxiliary circuits Verifi cation of making and breaking capacity of the apparatus Verifi cation of making and breaking capacities of earthing switch Mechanical operation tests Arc-withstand testing The shipping registers require that the switchgear be tested to ensure it remains unaffected by: High ambient temperatures Inclination Vibration Routine factory tests include: Visual inspection and check Mechanical sequence operations Cabling check Electrical sequence operations Insulation testing Resistance measurement of the main circuits Type tests Short-time and peak withstand current The test ensures that the main power and earthing circuits are able to withstand the stresses inflicted by a short-circuit current without being damaged. The earthing system of the withdrawable apparatus and the earthing busbar of the switchgear are included in the test. The mechanical and electrical properties of the main busbar system and of the top and bottom branch connections remain unchanged, even when a short circuit occurs. Temperature rise The temperature rise test is carried out at the rated current value of the switchgear unit and is used to ensure that the temperature does not become excessive inside the unit. During the test, both the switchgear and any additional apparatus, such as circuit breakers, contactors and switch disconnectors, are checked. An apparatus subject to testing in free air is able to withstand higher rated currents than those connected to a switchgear unit, which means the rated current of the apparatus depends on the characteristics of the switchgear and on the relevant ventilation system (natural or forced). Dielectric These tests check if the switchgear is able to withstand lightning surges and the power frequency voltage. The power frequency withstand-voltage test is carried out as a type test, but also routinely on every switchgear unit manufactured. Apparatus making and breaking capacity All circuit breakers are subjected to the rated current and shortcircuit current breaking tests. Furthermore, they are also subjected to the opening and closing of capacitive and inductive loads, capacitor banks and cable lines. Earthing switch capacity The earthing switch of the UniGear switchgear can be closed in case of a short circuit and is normally interlocked to avoid being used on live circuits. However, should this happen for any one of several reasons, the safety of the personnel operating the installation is fully guaranteed. Mechanical operations The mechanical testing of all the operating parts highlights thereliability of the apparatus. Experience in the electrotechnical sector shows that mechanical problems are one of the most common causes of a fault in an installation. The switchgear and apparatus it contains are tested by carrying out a high number of operations, higher than those which are normally carried out in installations in service. Moreover, the switchgear components are part of a quality program system and are regularly taken up from the production lines and subjected to mechanical life tests to verify that the quality is identical to that of the components subjected to the type tests. 8 Type tests I UniGear 550

9 Arc proof When developing medium-voltage switchgear, personnel safety must take priority, which is why the UniGear 550 switchgear has been designed and tested to withstand an internal arc caused by a short-circuit current at the same level as the maximum shorttime withstand level. The tests show that the metal housing of the UniGear switchgear is able to protect personnel working near the switchgear should a fault occur that results in an internal arc. An internal arc is among the most unlikely of faults, although it can theoretically be caused by various factors, such as: Insulation defects due to a deterioration in component quality, which can be caused by adverse environmental conditions and a highly polluted atmosphere Over-voltages of atmospheric origin or generated by the operation of a component Incorrect operation resulting from not following proper procedures or inadequate training of personnel in charge of the installation Breakage or tampering of the safety interlocks Overheating of the contact area due to the presence of corrosive agents or insufficiently tightened connections Small animals in the switchgear Material left behind inside the switchgear during maintenance operations While the characteristics of the UniGear switchgear notably reduce the incidence of these causes, some of them cannot be eliminated entirely. The energy produced by an internal arc causes the following phenomena: An Increase in the internal pressure An increase in temperature Visual and acoustic effects Mechanical stresses on the switchgear structure Melting, decomposition and the vaporization of materials Unless suitably controlled, operators could incur serious injury due to the shock wave, flying parts and the doors opening. In addition, they could be burned by the hot gases emitted by an internal arc. personnel who must access the switchgear after a fault has occurred. The IEC 7-00 standard describes the methods to be used to carry out the tests and the criteria which the switchgear must conform to, such as: The doors of the switchgear must remain closed and there must be no openings in the cover panels Any part of the switchgear which may be hazardous for personnel must not be ejected No holes must appear in any part of the switchgear accessible by personnel The vertically and horizontally arranged fabric indicators placed outside the switchgear must not get burnt All the switchgear earthing connections must remain effective A metal enclosed switchgear that successfully fulfills these criteria are designated as follows: General: Internal arc classified (IAC AFLR) Accessibility: Given as A, B or C, where (A) means the switchgear is accessible to authorized personnel only, to all (B), not accessible due to installation (C) Test values: Test current in ka, and duration in seconds When installing the switchgear, some fundamental points must be taken into consideration, such as: The level of the fault current (...5 ka) The duration of the fault (0... s) Escape routes for the hot and toxic gases given off by combustion of materials. Dimensions of the room, with special attention paid to the height. The parameters of each specific plant mean that evacuation of the hot gases and burning particles must be carefully checked to ensure and maintain personnel safety. The UniGear switchgear is fitted with a complete range of solutions to deal with all requirements when evacuation is possible inside the room, but also when it is not compatible with the plant characteristics, as in the case of shipping installations. The tests ensure that the compartment doors remain closed and that no components are ejected from the switchgear even when it is subjected to very high pressures. Additionally, the tests check that no flames or incendiary gases are emitted. Moreover, the lack of holes in the external, freely accessible parts of the housing, and the assurance that all the connections to the earthing circuit remain intact, guarantee the safety of the UniGear 550 I Arc proof 9

10 Arc proof The UniGear 550 switchgear offers complete passive structural protection against the effects of a fault due to an internal arc for a period of s up to.5 ka. ABB has also developed protection systems which allow very important objectives to be achieved: The detection and repair of the fault in less than 00 ms Minimal effects of the fault on the apparatus Minimal down time For active protection against an internal arc, devices consisting of various types of sensors which detect faults immediately and carry out selected opening of circuit breakers can be installed in the various compartments. Arc with stand test 0 Arc proof I UniGear 550

11 Vacuum circuit-breakers The Vmax medium-voltage circuit-breaker interrupters are the same as those used in the VD and VM series, thereby ensuring they all share the same characteristics, i.e. interruption of the currents without arc chopping and over-voltages, and extremely rapid recovery of the dielectric properties after an interruption. Operating mechanism The Vmax series is fitted with an easy-to-use mechanical operating mechanism, which is derived from the same mechanism that equips the VD series. The stored energy operating mechanism with free trip therefore allows the opening and closing of operations independent of the operator. The spring system of the operating mechanism can be recharged manually or by means of a geared motor. The apparatus can be opened and closed using the pushbuttons located on the front of the operating mechanism, and by means of the electric releases (shunt closing, shunt opening and undervoltage). Vacuum circuit-breakers-vmax Vmax medium-voltage circuit breakers are used in electrical distribution for the control and protection of cables, overhead lines, transformers and distribution substations, motors, transformers, generators and capacitor banks. They are the synthesis of ABB vacuum interrupter technology, and excellence in breaker design, engineering and production. With specifications of up to kv (rated voltage), 000 A (rated current) and.5 ka (internal arc withstand current), Vmax breakers are ideally suited to the narrow (550 mm) UniGear ZS type switchgear panels. Insulating monobloc The Vmax structure is particularly innovative in that it features a single insulating monobloc instead of three distinct separate poles to house the three vacuum interrupters. The monobloc and mechanical operating mechanism, with a spring for controlling energy storage, are fixed to a sturdy metallic frame. This compact structure ensures the same sturdiness and mechanical reliability as a traditional circuit breaker consisting of an operating mechanism/pole base cover and three separate poles. The low speed of the contacts together with the reduced run and mass container, limit the energy required for an operation, and therefore guarantee extremely limited wear on the system. This means the circuit breaker requires minimal maintenance. The circuit breaker is always fi tted with a mechanical antipumping device to prevent repeated opening and closing following simultaneous and maintained opening and closing commands (local and/or remote). Truck The poles and operating mechanism are fixed onto a metal supporting and handling truck. The truck is fitted with a set of wheels, making the insertion and removal of the apparatus into the switchgear panel possible with the door still closed. The truck allows the circuit breaker to be properly earthed by means of the metallic structure of the switchgear. Apparatus-Operator Interface The circuit-breaker user interface is fitted with the following parts: Open button Close button An operation counter Circuit-breaker open/closed indicator Operating spring charged/discharged indicator A manual spring operator A selector for the exclusion of under-voltage release (optional) UniGear 550 I Vacuum circuit-breakers

12 Standards IEC 7-00 for circuit-breakers Circuit-breaker Vmax/L Vmax/L 7 Vmax/L Standards GB IEC 7-00 CEI 7- (File 75) Rated voltage Ur [kv] 7.5 Rated insulation voltage Us [kv] 7.5 Withstand voltage at 50Hz Ud ( min) [kv] 8 8 Impulse withstand voltage Up [kv] Rated frequency fr [Hz] Rated normal current (0*) () lr [A] Rated breaking capacity Isc [ka] (rated short-circuit symmetrical current) Ik [Ak Rated short-time () Ir [kv] withstand current( s) Making capacity Ip [ka] Operation sequence [O-0. s-co-5 s-co] Opening time [ms] Acr time [ms] Total interruption time [ms] Closing time [ms] Standards I UniGear 550

13 Uses and features UniGear 550 units are designed to be used in conjunction with the following instruments: Ring core-type CTs (standard) Block-type CTs (optional) Bushing-type CTs (optional) Ring-core type CTs With the advent of new digital protection and measuring instruments, the use of low-power measuring instruments can be easily extended to primary distribution switchgear. The CTs are fixed to a support, i.e. a CT rod, inside the switchgear which is positioned above the cable terminals. This ensures the CTs remain unaffected by the number of cables, cross sections or terminals used. Each CT rod is designed to accommodate a maximum of two CTs per phase (metering and protection) and it has the following dimensional constraints: A minimum internal diameter of 59 mm A maximum external diameter of 00 mm A maximum height of 00 mm Block-type CTs As an alternative to the above specified current measuring instruments, a dedicated combination of block-type current transformers, current sensors and combi-sensors can be used. These are used in case of special requirements, such as fiscal metering on incoming feeders (Class 0.), differential protection on line feeders, etc. The use of block-type CTs will allow for the application of ring core-type CTs on cables. Earthing switch ST-UG The UniGear 550 panel is equipped with the patented earthing switch type ST-UG, which features a rectilinear movement. The switch is fitted with a snap-action operation mechanism for positive high-speed closing. It is dimensioned to conduct the rated short-circuit current when closed under load conditions. The speed of the snap-action closing operation is independent of the controls. The switch is equipped with an earthing blade which connects the three phases to the earthing pins located on the copper bars of the cable connecting system. The earthing bar is electrically connected to ground by a standard copper conductor. The closing mechanism of the earthing switch functions independently of the rotation of the drive shaft, and the switching speed and torque achieved are independent of the action of the operating mechanism. During the opening process, however, the toggle springs have no effect on the speed of contact separation. A manual operating lever is provided to operate the switch. The switch has been tested for two closing operations at 00% of the rated short-circuit current. The device is provided with auxiliary switches, operated by the rod mechanism, to indicate the status (open or closed) of the switch. Other components, such as a locking magnet, padlock, and key locks for the open and closed positions are available on request. Bushing-type current transformers In a large part of the market, especially among those who apply BS concepts, the bushing-type CT is very common. Ring core-type CT Block-type CT Bushing-type CT Earthing switch ST-UG UniGear 550 I Uses and features

14 Feeder protection General The protection functions can be divided into two major groups: () Those that trip the circuit breaker of the faulted feeder if a short circuit, or an earth fault, for example, occurs. () Protection functions that monitor the operation of the feeder and the rest of the network. voltage, frequency and overload protection functions (alarming/tripping) are typical monitoring functions. The basic requirements of a protection system are adequate sensitivity and speed of operation, taking into account the minimum and maximum fault currents occurring in the intelligent electronic device (IED)-such as the REF5-locations, selectivity, monitoring inrush currents and the thermal and mechanical strength of the lines behind the relaying point. In many cases, the above requirements can be fulfilled with nondirectional/directional current or multi-staged impedance measuring functions. The purpose of an over-and under-voltage protection system is to monitor the voltage level of the network. If the voltage level deviates from the target value by more than the permitted margin for a specific period of time, the voltage protection system limits the duration of the fault and any resulting stress on the mechanism. To prevent major outages due to frequency disturbances, the substations are usually equipped with under-frequency protection relays, which in turn control various load-shedding schemes. These are just a few examples of the main protection functions for feeders. more details can be found in the technical documentation produced for ABB protection relays. Applications and features Depending on the needs of the customer, a suitable IED type can be selected and configured in a way that provides an overall solution for different feeder types. Generally, the required protection functionality of the feeder types mentioned above differs greatly depending on the characteristics of the fault current sources and the types of advanced functions that may be needed to fulfill the basic requirements of the protection application. A few examples will now be given to illustrate the requirement level. Fig. : Comparison of standard and high requirement feeders Feeder protection I UniGear 550

15 Recommended products ABB supplies a wide range of feeder protection relays and terminals to fulfill the requirements of each unique application. For an application with standard requirements and a need for additional features, the REF5, REX5 units are excellent choices. for applications with higher functionality requirements, the multifunction terminals REF5_ should be selected. Fig. Typical standard feeder I Fig. Typical high requirement feeder Fig. Fig. ) Optional intermittent E/F protection UniGear 550 I Feeder protection 5

16 Transformer protection General The power transformer is an important component and one of the most valuable individual units in the power distribution network. A highly reliable power transformer is therefore of particular importance in preventing disturbances in the power distribution system. Although high-quality power transformers are highly reliable, faults including insulation breakdowns sometimes occur. These faults, which appear as short circuits and/or earth faults generally cause severe damage to the windings and transformer core. The damage is proportional to the fault clearing time so the power transformer must be disconnected as quickly as possible. The power transformer has to be transported to a workshop for repair, which is a very timeconsuming process. The operation of a power network in which the power transformer is out of service is always cumbersome. Therefore, a power transformer fault often constitutes a more severe power system fault than a line fault, which usually can be rectified rather quickly. It is therefore extremely important that fast and reliable protection relays are used to detect transformer faults and initiate tripping. Applications and features ABB divides transformer applications into standard transformer protection applications (typically< MVA) and high requirement transformer applications (typically>5 MVA). Basic protection requirements (< MVA) include: Sudden pressure (buchholz) relay Differential protection Over-current protection Earth fault protection Overload protection Unbalance protection Oil level monitoring High requirements (>5 MVA) are: Sudden pressure (buchholz) relay Differential protection Over-current protection Restricted earth fault (REF) protection Overload protection Unbalance protection Over/Under-voltage protection Over/under-frequency protection Oil-level monitoring The size, voltage level and importance of the power transformer determine the extent and choice of the monitoring and protection devices used to limit the damage of a possible fault. When compared to the total cost of the power transformer and the costs caused by a power transformer fault, the cost of the protection system is negligible. Transformer protection I UniGear 550

17 Motor protection General Motor protection generally provides over-current, unbalance, earth-fault and short-circuit protection. However, as well as electrical faults, one of the worst threats facing motors is overheating, which comes from improper operation. That is why the fundamental issue for motors is thermal protection. ABB's solutions focus on advanced thermal protection that prevents the improper use of the motors. Thermal overload protection is needed to protect the motor against both shortand longtime overload and it is extremely important for the performance of the motor. Short overload conditions mainly occur during motor start-up. There are four crucial elements in thermal motor protection: () Most importantly, the thermal overload protection function monitors the thermal load and records related events. () A cumulative start-up time counter supporting the overload protection limits the number of consecutive cold starts. () Thermal stress during any single start-up condition is monitored by the start-up supervision function, which protects the motor from becoming locked and extending start-up times. () The fourth element is thermal protection based on Resistance. Temperature detector (RTD) sensors. As RTD sensors directly measure the temperature of the stator winding, bearings, etc., this type of thermal protection is especially useful if the motor's cooling system is blocked. Improper use of running motors does not necessarily break the equipment, but shortens its lifespan. Therefore, a reliable and versatile motor protection system not only protects the motor but it also prolongs its life, which contributes to improving the return on investment of your motor drive. Applications and features Thanks to comprehensive communication protocols, including the widely used industrial protocols such as Modbus RTU/ASCII and profibus DP, ABB motor protection relays and terminals can be easily integrated into various control systems. UniGear 550 I Motor protection 7

18 Motor protection Recommended products The REF5/5/55 transformer terminals are designed for the comprehensive protection, control, measurement and supervision of two-winding power transformers and power generator transformer blocks in utility distribution networks. It is suitable for applications where on-load tap-changer control is required. The functionality for standard transformer protection is provided in the REF5plus terminal. Fig. Typical standard transformer protection I Fig.5 Typical high requirement transformer protection Fig. Fig. 5 8 Motor protection I UniGear 550

19 Communication General In the complex world of communication, ABB puts a great deal of effort into finding communication buses and protocols that ensure a secure and efficient data flow. In addition to the recently introduced IEC 850 protocol, ABB uses LON and SPA communication buses for communication between relays. In addition, protocols such as IEC , modbus, profibus and DNP.0 and OPC interface are available. Depending on the application area, different protocols are used according to industry de-facto standards. Utility applications IEC 850 IEC 850 is a flexible, future-proof standard that adapts to changing requirements, philosophies and technologies. The function of the IEC 850 standard is to ensure essential features, such as interoperability between devices from different suppliers, the free allocation of functions, adaptability to ever-changing communication technology and ease of engineering and maintenance. Because of the long-term stability of the IEC 850 standard, investments in utilities are safeguarded. IEC IEC is a standard protocol designed exclusively for communication between protection IEDs and a master system. Allowing IEDs of different vendors to be connected to a common master system, it is widely supported within distribution automation. The range of information that can be transmitted with the IEC protocol is smaller than the information range available through the LON, SPA and IEC 850 protocols. DNP V.0 The DNP protocol, based on the IEC standard family, was originally developed by a single vendor, but has now evolved into an open standard controlled by a user group. It is designed for local communication within a substation, between a protection IED and an RTU (which forwards information to a remote SCADA system). Additionally, protection IEDs can be connected directly to a remote system using this protocol. The DNP has a multitude of options enabling it to be optimized for different types of applications and communication environments (it can, for instance, be optimized to run over a slow communication link). Since its inception, ABB has taken a leading position in the elaboration of corresponding standards in the field of substation automation. SPA The SPA protocol is supported by all ABB relays and enables a wide range of distribution automation functions. It is a proven serial bus that has formed the backbone communication protocol for ABB relays for many years. The information content that can be transferred is similar to that of the IEC 850. To ensure EMI immunity, the SPA protocol is run over a fiberoptic network. LON The LON protocol is a fast bus-based protocol featuring both vertical (to a master system) and horizontal communication. When horizontal communication is used, IEDs are able to exchange interlocking information, for example, over the communication bus. This reduces the need for hard wiring between devices, thus saving costs. The LON bus runs at a substantially higher speed than the serial buses. ABB has defined extensions to the basic LON protocol, enabling any information appearing in distribution automation to be efficiently and securely transferred.to secure immunity against EMI disturbances, the LON bus runs over optical fibers. UniGear 550 I Communication 9

20 Industrial applications OPC OPC is commonly used to interconnect systems in industrial automation applications. A data exchange system using OPC consists of an OPC server (which provides data and services) and an OPC client (which receives data from and uses the services of the OPC server). The OPC server and the OPC client are both software components running on PCs. The interaction between an OPC server and an OPC client can take place either locally in one PC or over a LAN/WAN computer network (in the latter case using DCOM as the intermediate protocol). Data from protection IEDs can be made available in different ways through an OPC interface. One option is to use the SPA/OPC or LON/OPC servers, which collect data from protection IEDs using LON or SPA and make the data available in the OPC environment. Another option is to connect the protection IEDs to the COM0 gateway. Any data in the COM0 can be made available to an OPC client. Profibus DP V Profibus is a major de-facto standard for connectivity to industrial systems. All ABB relays can be connected to Profibus master systems using the SPA-ZC 0. SPA/Profibus converter. The SPA-ZC 0 supports the Profibus DP V protocol and can handle up to SPA devices. The speed of the Profibus is comparable to that of LON and it is substantially higher than the speed of serial protocols. To ensure EMI immunity, Profibus runs over a double-shielded twisted pair cable. Profibus is generally used when protected IED information is to be transmitted to a controller or PLC. Modbus The modbus protocol was first introduced by modicon Inc. and is a widely accepted communication standard for industrial controllers and PLCs. It is a serial protocol designed for the transfer of binary and numeric data in a generic format. The modbus as such does not recognize the data model of a distribution automation application (as. the IEC 850 does). Modeling is done in the application of the modbus master system. Modbus typically uses a twisted pair RS-85 bus network as a transmission medium. OPC is usually used when the data from protection IEDs is to be transmitted directly to a control system (as opposed to profibus and modbus that usually supply data to a controller or a PLC). Via PC or over a LAN/WAN computer network (in the latter case using DCOM as the intermediate protocol), data from protection IEDs can be made available in different ways through an OPC interface. One option is to use the SPA/ OPC or LON/OPC servers, which collect data from protection IEDs using LON or SPA and make the data available within the OPC environment. Another option is to connect the protection IEDs directly to the COM0, thereby making data available to an OPC client. OPC is usually used when the data from protection IEDs is to be transmitted directly to a control system (as opposed to profibus and modbus that usually supply data to a controller or a PLC). 0 Industrial applications I UniGear 550

21 Arc protection General An electric arc short-circuit in a switchgear installation is normally caused by a foreign object entering the cubicle or by a component failure. The arc causes explosion-like heat and pressure that can extensively damage the switchgear and the operating personnel. An adequate arc protection system protects a substation against arc faults by minimizing the burning time of the arc, thus preventing excessive heat and damage. It minimizes material damage and allows power distribution to be smoothly and safely restored. The system can also bring cost benefits even before an arc fault occurs. As older switchgear is more prone to arc faults, an arc protection system will effectively extend the life of your switchgear and make more of your investment. But more importantly, arc-protection technology can help save lives. Applications and features Sources of arcing may be insulation faults, the incorrect operation of devices, defective bus or cable joints, overvoltage, corrosion, pollution, moisture, ferroresonance (in instrument transformers) and even ageing due to electrical stress. Most of these arc-fault sources could be prevented by sufficient maintenance. However, in spite of the precautions taken, human errors can lead to arc faults. Time is critical when it comes to detecting and minimizing the effects of an electric arc. An arc fault lasting 500 ms may severely damage the installation. If the burning time of the arc is less than 00 ms the damage is often limited, but if the arc is extinguished in less than 5 ms, the effect goes almost unnoticed. Generally applied protection relays are not fast enough to ensure safe fault clearance times when arc faults occur. The operation time of the over-current relay controlling the incoming circuit breaker may, for instance, have to be delayed by hundreds of milliseconds for selectivity reasons. This delay can be avoided by installing an arc-protection system. The total fault clearance time can be reduced to a maximum of.5 ms, plus the circuit breaker's contact travel time. Furthermore, in cases of cable compartment faults, autoreclosures can be eliminated by employing arc protection. Recommended products The arc protection system, REA0, with its extension units, REA0, REA05 and REA07, are designed to be used for the protection of medium and low-voltage air-insulated switchgear. The central unit type REA0 can operate independently or together with other REA0 units. With tripping times as low as.5 ms, REA is the fastest arc protection system on the market. REAis equipped with a fast integrated over-current sensing element and it works independently of other feeder protection units. The REF0 feeder protection relay includes an optional arc protection function for the feeder cubicle. Fig. 8 Typical setup with REA0 and REA0 subunits REA 0 Trip Trip Light REA 0 REA 0 UniGear 550 I Arc protection

22 Selection guide Application REF5 REX5 REF5_ RET 5_ REM5_ REM0 REA0_ Feeder application High requirement feeder application Transformer application High requirement transformer application Motor protection High requirement motor application Generator & synchronous motor Distance protection Arc protection for feeder cubicle Arc protection system Communication IEC IEC 850 * * * * * * DNP.0 SPA LON * * Modbus Profibus * * * * * * Additional functions Fault locator Web interface CAN interface On load tap chemger control Disturbance recording Withdrawable release mechanics Condition monitoring Single line diagram HMI** Remote contro Power quality monitoring Sensor inputs Auto re-closure 5 shots shots 5 shots RTD*** inputs 8 8 * With interface adapter ** HMI-human machine Interface ***RTD-resistive temperature detector Selection guide I UniGear 550

23 REF5plus multifunction protection and control unit replaced while the central unit remains in service and all the measurement, control and protection functions are guaranteed during maintenance work. All the connections are made by means of plug socket connectors to optimize service and maintenance operations. Machine-user interface The UniGear switchgear is easily operated via the user interface of the REF5plus unit. All the apparatus control operations, measurement readouts, detection of signals and parameterization of functions can be carried out directly from the front of the unit, or by means of a laptop computer connected to the optic communication gate located on the front. The REF5plus unit integrates all the secondary functions relevant to a switchgear unit in a single module fitted with a watchdog. Thanks to the flexibility of its software, the unit is able to satisfy a vast range of installation requirements. The high level of functionality of the REF5plus unit is supported by a simple and easy-to-use user interface. With a REF5plus unit, each medium-voltage UniGear panel becomes an integrated and independent unit able to carry out functions such as protection, measurement, control, signaling, interlocking, automation and communication. The REF5plus is characterized by A single interface between the switchgear and operator for the installation panels: feeder, transformer, motor,generator, power correction banks, bus-tie and measurements units.- Single type of spares parts and accessories: a single hardware unit Low maintenance. Good preventive maintenance severely limits the faults caused by tampering and errors The functions can be easily modified and upgraded, even when the switchgear is in service, by means of unit configuration software switchgear Hardware The device central unit is housed inside the auxiliary compartment of the switchgear while the user interface is located on the door of this compartment. The two pieces are connected together by means of a simple communication cable. The user interface can be Central unit The REF5plus central unit consists of several electronic modules: Feeder. The apparatus is fitted with a multi-voltage internal feeder and can operate from 8 Vdc to 0 Vdc. Thanks to its digital technology, consumption is very low Digital inputs. Each unit is fitted with a minimum of digital inputs to interface with the apparatus-circuitbreaker and earthing switch-contained in the switchgear. These can be increased to a maximum of. They operate between 0 Vdc and 50 Vdc. and are freely programmable. Digital outputs. These consist of free contacts made available by bi-stable relays. Each unit has at least 8 outputs to operate the switchgear apparatus and the minimum signals required. The number of outputs can be increased to a maximum of. They operate up to 50 Vdc/ac. and are freely programmable. - The output that controls circuit-breaker opening can also carry out control of circuit continuity. - By means of the static outputs with which it is fitted (from to a maximum of ), it is possible to interface conventional supervision systems by means of active and reactive power measurements with impulse emitter. Analogue inputs. Each unit is fitted with 8 analogue inputs needed to carry out measurements and protections. - Signals coming from conventional CTs ( A and 5 A) and VTs (00 V and 0 V) or from measurement sensors (based on a Rogowski coil and resistive divider) can be acquired. Analogue outputs. The analogue outputs the unit can be provided with make it possible to interface conventional supervision systems by means of the integrated measurement functions. Each output can be freely programmed as ma or...0 ma. UniGear 550 I REF5plus multifunction protection and control unit

24 REF5plus multifunction protection and control unit Communication The REF5plus unit can be connected to supervision and process systems by means of an integrated communication function. This turns the apparatus into a window through which the system accesses all the switchgear information and makes the following functions possible: Monitoring Control Parameterization of the protection functions Measurements Monitoring of all operating apparatus Disturbance oscillography The following protocols are available for connection to the supervision and automation systems: ABB SPA-bus LON-bus in accordance with ABB lon application guide (LAG.) IEC (in accordance with VDEW specifi cations) MODBUS RTU Use of the LON-bus protocol and relative LIB 5 library allows the REF5plus unit to be integrated into ABB supervision systems. Using the hardware configuration with two gates and the MODBUS RTU protocol, it is possible to create redundant system architectures, or independent connections to two different systems, for example, a supervisory control and data acquisition system (SCADA) and a process distributed control system (DCS). Synchronization The REF5plus unit can be connected to an external master clock (typically a GPS) by means of a dedicated optic input for synchronization. When synchronized using this method, the REF5plus units guarantee chronological recording of events within a maximum time of ms. The protocol accepted is IRIG-B. REF5plus multifunction protection and control unit I UniGear 550

25 Automatic transfer systems Automatic transfer systems (ATS) are used to give maximum service continuity by ensuring an uninterrupted supply of power. This is possible using various systems based on different kinds of techniques. The most common systems are described below with relevant average transfer times of. The first two systems on the list above are the simplest and can be made with conventional logics and instruments. They guarantee average transfer times and can therefore be used in installations where voltage gaps are not particularly critical. On the other hand, the other two systems: Delayed: 500 ms Depending on the residual voltage: 00 ms-00 ms Synchronised (ATS): 00 ms-500 ms High speed (HSTS): 0 ms-0 ms Synchronized ATS and ahigh speed transfer system (HSTS) require a microprocessor-based apparatus with high technological content. They guarantee fast transfer times and are generally applied in plants where the process times are particularly critical. Slower transfers times would cause serious malfunctions or even stoppages. ABB is able to offer all the transfer systems, from the simplest to the most complex. The REF5plus unit can be used in medium-voltage switchgear to manage automatic and manual transfer between two different incoming feeders. The time needed for automatic transfer using the REF5plus unit is between 00 ms and 00 ms (including the circuitbreaker operating times). This time can vary depending on the complexity of the software transfer logics. Switchgear equipped with suitably programmed REF5plus units are considered complete and efficient systems able to manage transfer between one power supply system and an alternative one or reconfigure the network, passing from double radial distribution to a simple system, in a fully automatic way. It is also possible to carry out the same operation manually from a remote control station, or from the front of the switchgear under the supervision of user personnel. Manual transfer first involves paralleling two parts of the power system. By means of the synchronism control function synchro-check (ANSI protection code 5) implemented from the REF5plus, the power supply lines are closed simultaneously as the voltage vectors become synchronized before being disconnected when the transfer has taken place. The applications described do not... Single-line diagram of UniGear switchgear with REF5plus architecture. This configuration is suitable for carrying out automatic and manual transfer (ATS), as well as switchgear protections and measurements. UniGear 550 I Automatic transfer systems 5

26 Typical units and technical data Single-line diagram of the typical units IF-incoming/outgoing feeder BT-bus tie R-bus riser RM-bus riser with measurements 5 M-measurements IFD-direct incoming/outgoing 7 IFDM-direct incoming/outgoing with measurement Typical units and technical data I UniGear 550

27 Single-line diagram of the busbar applications Current transformers Duct entry Earthing switch Graphical symbols Circuit-breaker Contactor Switch Isolating bar 5 Socket and plug 7 Current transformers 8 9 Earth 0 Cable entry Busbar entry Technical data...5 ka IF FM BT R RM M IFD IFDM DF Altemative solutions Depth(mm) Incoming/outgoing Incoming/outgoing with measurements Bus-tie Riser Riser with measurements Measurements Direct incoming/outgoing Direct incoming/outgoing with measurement Switch-disconnector unit UniGear 550 I Typical units and technical data 7

28 Typical units and technical data Width: 550 mm Depth: 0 A~50 A: 0 mm 00 A~000 A: 90 mm Deeper: 50 mm Height: 00 mm Height with gas exhaust duct: 75 mm E Unit compartments A: Apparatus B: Main busbars C: Feeder D: Instruments E: Gas exhaust duct D B A C 8 Typical units and technical data I UniGear 550