ELECTRIC DRIVE CONTROL SYSTEMS (Parameterization of Thyristor Converters SIMOREG DC MASTER)

Transcription

1 Ministry of education and science of Russian Federation Y.V. Plotnikov ELECTRIC DRIVE CONTROL SYSTEMS (Parameterization of Thyristor Converters SIMOREG DC MASTER) Electronic textbook The textbook is intended for the Masters in the direction of Electrical engineering, Electromechanics and electrotechnics of specialty Electric drives and electric drive control systems Science editor: Associate Professor, Candidate of technical science N.D. Yasenev Produced by Electric drive and automatics of industrial plants department Methodological course book contains the detailed description of methods and principles of parameterization of the thyristor converters Simoreg DC master for direct current electric drives. The methodical course book is intended for the Electric Drive Control Systems discipline. Methodical course book was composed according to the work programme of profile Electric drive and automation of industrial plants and technological complexes. Methodological course book is meant for Master of Science of full time education form. Yekaterinburg 2012

2 CONTENTS TABLE OF CONTENTS... 2 INTRODUCTION GENERAL INFORMATION ABOUT SEMOREG CONVERTOR BRIEF DESCRIPTION OF CONTROL SYSTEM IN THE SIMOREG DC MASTER CONVERTER USING THE BICO TECHNOLOGY IN THE SIMOREG DC MASTER CONVERTER PARAMETERIZATION OF SIMOREG DC MASTER PARAMETERIZATION OF SIMOREG DC MASTER CONVERTOR WITH USING SIMPLE OPERATOR CONTROL PANEL The LEDs assignment The buttons assignment Parameter types Parameterization example from simple operator control panel PARAMETERIZATION VIA THE SERIAL INTERFACE WITH USING THE DRIVE MONITOR SOFTWARE THE PARAMETERIZATION SEQUENCE OF SIMOREG DC MASTER CONVERTER Access level setting to the converter parameters and factory reset Setting the rated converter voltage and current Setting the motor rated data The setting of speed sensor parameters The setting of armature current ramp-function generator The limitation of armature current and electromagnetic torque Parameterization of ramp-function generator Automatic parameterization of armature current closed loop Automatic parameterization of speed closed loop THE PARAMETERIZATION OF THYRISTOR CONVERTER FOR WORKING IN THE PROFIBUS-DP NETWORK Brief information about the PROFIBUS-DP The Simoreg DC Master convertor as a slave unit on the PROFIBUS Control and Status words and speed setpoint signal The using of PKW mechanism for processing parameters The parameterization of Simoreg convertor for working from PROFIBUS-DP THE PLOTTING OF TRANSIENTS OSCILLOGRAMS WITH USING THE DRIVE MONITOR SOFTWARE GLOSSARY REFERENCES

3 INTRODUCTION Nowadays the Microprocessor-Based Converters are widely used in the different electric drive systems and technological complexes. Despite of some disadvantages (the maintenance requirements, low power factor, low reliability of DC motor etc.), compare to the alternating current electric drive these systems have some advantages, such as: low coast four quadrant operation; continuous duty at low speeds with full electromagnetic torque; high starting torque; wide speed range for constant power; minimal space requirements. The adjusting of microprocessor control system in the thyristor convertor is made by means of parameters, which are responsible for some special functions of control system. Often, the special software is used to vary the convertors parameters and to monitor the electric drive state. Therefore the practical skills of parameterization of microprocessor control systems of thyristor converters is a one of most important skills of modern engineers. The Simoreg DC Master convertors are the part of Siemens automation technologies. The Simoreg converts family is available for wide power range from 6.3 to 2500 kw. It has a wide range of different functions, which are widely used on practice. The availability of digital and analog inputs/outputs and network connection allow user to connect converter to the external control systems and sensors. The main feature of Simoreg DC Master Convertor is that it allow user to modify its own control system by means of BICO technology. It means that closedloop control functions are implemented in the software as program modules that are wired up via parameters. The Simoreg DC Master with communication board can also be used as a slave unit in the different industrial networks, such as PROFIBUS. And in the Simoreg 3

4 converter it is possible to set parameters from the programmable logic controller by means of PROFIBUS network. This methodological course book contains detailed description of methods and principles of parameterization the microprocessor control system in the thyristor converters Simoreg DC master for direct current electric drives. The methodological course book is belonged to the Electric Drive Control Systems discipline. 1. GENERAL INFORMATION ABOUT SEMOREG CONVERTOR 1.1. Brief description of control system in the Simoreg DC Master Converter The functional diagram of control system, which is used in the Simoreg DC Master converter, is shown on the figure 1 [5]. This control system is based on the subordinate control principles. In the armature circuit control system consists of inner armature current closed loop and outer speed closed loop. In the current control system the armature precontrol is used to increase the performance of current loop in the interrupted current mode of thyristor converter. That is in the current closed loop the technical linearization of plant in the interrupted current mode is used. Armature gating unit is used to produce the control angle of thyristor convertor from the control voltage signal and to limit the control angel on the acceptable levels. Also in this functional block the current direction is selected. To protect motor from overload conditions the current and torque limitation blocks are used. The P or PI speed controller can be used in the automatic speed control system. The selection of controller type is produced by means of some parameters, which are described in detail below. It is also possible to set additional filters both in the speed and current closed loops. The actual speed signal comes from the speed sensor. The different speed sensor can be used in this control system from different encoder to analog tachogenerators. It is also possible to build sensorless speed control system. 4

5 The speed limitation block protects motor from the speed exceeding and is set on the input of the speed control system. The ramp-function generator (RFG) allows to limit the dynamic motor torque in the transient mode of electric drive. In this system both the second order RFG and the first order RFG can be used. The selection of RFG type is produced by means of serial parameters. Other parameters set an acceleration and deceleration time of electric drive. The control system in the field circuit consists of inner field current closed loop and outer electro-motive force (EMF) closed loop. In the both loops the precontrol technology is used to increase the performance of control system. The field current limitation is used to protect field circuit from the high field current. This nonlinear element allows to flow field current only in positive direction. The proportional-integral EMF controller is used to compensate the persistence in the EMF calculation circuit. The actual EMF value is calculated based on the armature current and voltage signals. Than calculated EMF signal flows through the nonlinear element with module characteristic. 5

6 6 Fig. 1. Simplified functional diagram of control system in the SEMOREG DC Master Converter

7 1.2. Using the BICO technology in the Simoreg DC Master converter The connectors and binectors are the basis of BICO technology (BInector COnnector), which is used to connect the different functional blocks each other and to build the different control systems. The inputs and outputs of each functional block are available in the form of connectors. To put in other words, connector is a 16 or 32 (double-word connector) bit signal of some functional block. Connectors have a value range of 200 % to %. The connections between individual function blocks can be selected by means of convertor parameters. The binector is a logic value and can be equal 0 or 1. For example, some binector is used as a start button of electric drive, while the some connector is used as a speed setpoint value. There are many different freely assignable function blocks in the Simoreg DC Master convertor such as: fault and alarm message triggers; connector / binector converters; mathematical functions (adders, substractors, switchable sign inverters, multipliers, dividers, absolute-value generators etc.); limiters and limit-value monitors; processing of connectors (maximum and minimum selectors, averagers, tracking and storage elements etc.); position deviation acquisition and root extractor; control elements (integrators, derivative and delay elements, technological controllers etc.); ramp-function generators; counters; logical functions (and, or, exclusive or, decoders and demultiplexers, inverters, RS flipflops, timers etc.). These functional blocks allow user to realize the complex automatic control system of electric drive. The connectors and binectors also allow to modify existing control system according to the special electric drive requirement. 7

8 The control system structure of Simoreg convertor is presented in view of functional diagram in the operating instruction [5]. The description of different elements on the Simoreg functional diagrams are shown in the table 1. Indication Description of main elements for BICO structure Description 1 2 Table 1 Binector is a logical signal, which may have two value 0 or 1. The binector is used to send and receive logical signals both in the inner circuit of convertor and external signals from other devices. Writing form: В ХХХХ, where ХХХХ binector number. Connector 16 or 32 bit signal, which is formed in the converter program or converted from the analog signal. There are two connector types: К ХХХХ 16 bit connector; КК ХХХХ 32 bit connector; where ХХХХ connector number. Hard connected binector (selection is not possible) Hard connected connector (selection is not possible) The binector selection. In the brackets the factory setting is shown. The values range is all binector numbers. The binector selection with using index parameter. In the brackets the factory setting is shown. The values range is all binector numbers. It is possible to select one of connected binectors by means of parameter index. Parameter index is selected via control words. Selection of one binector from factory ones with index parameter. Connector selection. In the brackets the factory setting is shown. The values range is all connector numbers. The connector selection with using index parameter. In the brackets the factory setting is shown. The values range is all connector numbers. It is possible to select one of connected connectors by means of parameter index. Parameter index is selected via control words. 8

9 1 2 Table 1. Continuation The connector selection with using index parameter. In the brackets the factory setting is shown. The values range is all connector numbers. It is possible to select one of connected connectors by means of parameter index. Parameter index is selected via control words. Selection of one from factory connector with index parameter. Link to the 152 page of functional diagram. 2. PARAMETERIZATION OF SIMOREG DC MASTER 2.1 Parameterization of Simoreg DC Master Convertor with using simple operator control panel The simple operator control panel (PMU Parameterization Unit) is a part of Simoreg DC Master Converter and consist of display, three status LEDs and three keys (fig. 2). This panel is mounted on the convertor face and allows user to adjust all parameters and select the structure of microprocessor control system. The parameter value and number is shown on the 5-digit segment display. The three LEDs are used to estimate the status of thyristor convertor. For example, the Ready LED shows that the electric drive, which is powered from thyristor convertor, is ready to run. Fig. 2. Simple operator control panel The description of LEDs and control panel buttons is shown below. 9

10 2.1.1 The LEDs assignment Run green LED is illuminated during the normal work (without errors) of electric drive with set electromagnetic torque direction. The state of electric drive can be displayed in the r000 parameter. Ready yellow LED is illuminated during the electric drive is in ready to run state. (o1 o7 parameter r000). Fault red LED is continuously illuminated whet the some error of electric drive is occurred during the work or parameterization process. The error number is indicated on the panel display. And LED is flashed during the alarm mode of electric drive and warns user about the invalid mode of thyristor convertor The buttons assignment The buttons assignment on the simple operator control panel is shown in the table 2. Table 2 The PMU buttons assignment Button Assignment Switches between parameter number, parameter values and index number of indexed parameters. Acknowledges the active fault messages (fault reset). Simultaneous pressing P and UP keys will lead to switch the active fault message to the background. Simultaneous pressing P and DOWN keys will lead to switch the active fault message to the foreground display on the PMU. Selects the higher parameter number in the parameterization mode. When the highest parameter number is reached, the pressing the key returns to the other end of parameters number range. Increases the selected and displayed parameter value in value mode. Increases the parameter index in index mode (for indexed parameters). Accelerates an adjustment process activated with the DOWN key (if both keys are pressed at the same time). Selects a lower parameter number in parameter mode. When the lowest number is displayed, the key can be pressed again to return to the other end of the number range (i.e. the lowest number is thus adjacent to the highest number). Decreases the selected and displayed parameter value in value mode. Decreases the parameter index in index mode (for indexed parameters). Accelerates an adjustment process activated with the UP key (if both keys are pressed at the same time). 10

11 2.1.3 Parameter types The main parameters of Simoreg convertor are displayed on the PMU as a P, r, U and n. Parameters for an optional supplementary board are called H, d, L or c parameters. The parameters list can be divided in to three main groups: Display parameters (r) are used to display the current values of controlled variables, such as speed setpoint, actual speed, actual voltage, armature current setpoint, armature current, etc. The values of display parameters are read-only values and cannot be changed. The most important display parameters are shown in the table 3. The display parameters description (selectively) Table 3 Parameter number Parameter description Value range Operating status display (selectively): o1.x o15.x r000 o1.x waiting for operating mode. o2.x wait for setpoint. o3.x test mode. o4.x waiting for armature voltage. o5.x waiting for field current. o6.x wait status before the line contactor is closed. o7.x wait for switch-on command (o7.0 waiting switchon from the terminal, o7.1 waiting switch-on via binector). o8.x waiting for acknowledgement of starting lockout. o9.x fast stop (OFF3). o10.x voltage disconnection (OFF2). o11.x fault. r001 Motor speed setpoint (terminals 4 and 5) from 200 to 199,99 % r002 Actual motor speed (terminals 103 and 104) from 200 to 199,99 % r019 Armature current value from 200 to 199,99 % [% from P100] r021 Electromagnetic torque setpoint after limitation from 200 to 199,99 % r023 Difference between the speed setpoint and actual speed from 200 to 199,99 % (speed error) r027 Display of ramp-function generator output from 200 to 199,99 % r037 Actual value of motor electro-motive force от 1500 до 1500 V r038 Armature voltage value от 1500 до 1500 V 11

12 Besides, by means of parameters P042, P044 and P046 in the parameters r041, r043 and r045 on the indication the values of different binectrors and connectors can be displayed. For example, the setting P042=K0142 (K0142 motor electromagnetic torque in percent) means that the in the parameter r041 the motor torque will be displayed. Setting parameters (P, U, n) are used to display and change converter parameters such as the rated motor current, thermal motor time constant, speed controller P gain, etc. These parameters are used to adjust the microprocessor control system in the thyristor convertor before the electric drive running. Indexed parameters (P, U, n) are used to both display and change several parameter values which are all assigned to the same parameter number. It means that some parameters of convertor have a number of different values, which are located in the different parameter indexes. The parameter index can be changed during the electric drive work. It allows users to change the control system setting depending of different working conditions of electric drive Parameterization example from simple operator control panel Let s consider the changing of starting time P303 from factory setting P303=10 sec to the value 5 sec: 1. To reach the parameter number from the operational display state (o7.0 see table 1), press the P key and then the Up or Down key to select parameter number P To reach the parameter index level from the parameter number level, press P and then the Up or Down key to select individual index in00. If you press P when a non-indexed parameter is displayed, you go directly to the parameter value. 3. To reach the parameter value P303 from the parameter index level press P button one more time. 4. By pressing the Up or Down keys, set the parameter value P303=5 sec and press P button to acknowledge the setting parameter value. 12

13 2.2 Parameterization via the serial interface with using the Drive Monitor Software The parameterization examples will be considered on the laboratory setup, which was described in detail in the methodological course book for laboratory work [4]. Before the laboratory setup will be powered it is necessary to connect the thyristor converter to the personal computer by means of special cable. Then, the power convertor is switched on, and after that the personal computer is switched on. The Drive Monitor Software allows users to adjust the parameterization of microprocessor control system in the converter and to plot the transients in the electric drive. At first it is necessary to choose the new parameter set with factory settings (fig.3). Fig. 3. New parameter set in the Drive monitor window Then, in the Drive properties windows it is necessary to select the Drive type Simoreg DC Master and point the software version 02.0 (fig. 4). The remainder parameters are selected according to the figure 4. Then it is necessary to replace the existing file SIMOREG DC MASTER_tmp.dnl with factory settings. After that, the parameters list with factory setting is appeared. Connection between the thyristor converter and PC is set by mean of key Online RAM on the control panel of Drive monitor software. In the case of successful connection, in the device status line the message Connection with device OK will be appeared. The main window of Drive monitor Software is shown on the fig

14 Fig. 4. The Drive Properties window If the connection PC with device is not set, it is necessary to check the Online Setting in the menu Tools. At first, it is recommended to select another COM port number (see fig. 6). Attention! The Online Setting parameters are changed only after the restarting of Drive monitor program. In the Drive Monitor Software the parameters are changed by means of dialog boxes, in which the parameter values are set or selected from the parameter list. In the left part of program, the parameter tree is situated, which is used to group the parameters of converter according to the functional destination (see fig. 5). 14

15 Fig. 5. Main window of Drive Monitor Software Fig. 6. Connection convertor with PC windows 15

16 Assignment of main buttons on the control panel of Drive Monitor (see fig. 5): Online-RAM is used to connect the PC with RAM (Random Access Memory) memory of thyristor converter. Online-EEPROM is used to connect the PC with EEPROM (Erasable Programmable Read-Only Memory) memory of thyristor converter. Parameter list complete is used to show the full parameter list. Free Parameterization is used to switch in the free parameterization mode. In this mode, at first, the parameter number is entered, and after that the parameter value is set. Parameterization guide launches the convertor parameterization wizard for quick taking into operation the thyristor converter. Online settings are used to set connection parameters between the convertor and PC. drive. Trace launches the transients building mode for direct current electric Download RAM downloads user parameter from file to RAM memory of thyristor converter. Download EEPROM downloads user parameter from file to EEPROM memory of thyristor converter. Upload base unit uploads the all parameters from the convertor to file. Upload base unit (only changes) uploads the parameters, which are different from factory setting, from the convertor to file. The other buttons assignment is intuitively obvious for users. In the lower part of the Drive monitor program, the start and stop buttons, speed setpoint field Setpoint [%] (when the electric drive is controlled from the program) and actual speed field Act. Val [%] are situated. 16

17 2.3 The parameterization sequence of Simoreg DC Master Converter For example, let s consider the parameterization of Simoreg DC Master Converter. The rated motor data and the laboratory setup description were considered in the first part of methodological course book for laboratory work [4]. After the convertor was powered, on the PMU display the current state of thyristor convertor will be displayed (for example o7.0). The state of Simoreg convertor is depicted in the r000 parameter (see table 2). The parameterization of microprocessor control system of thyristor convertor is carried out in the following sequence Access level setting to the converter parameters and factory reset 1. If the parameter setting is made in the first time or it is unknown the initial convertor state, it is recommended to reset the all parameters to factory setting. The setting of parameter P051 = 21 will leads to factory reset of converter parameters. After this setting, the restoring of parameter values to default and performing the initial converter offset adjustment will be executed. Then, parameter P051 is automatically set in the initial value P051= Set parameter P051 = 40 [Key parameters]. This value allow user to modify all parameters of thyristor converter. 3. Set parameter P052 = 2 [Selection of display parameters]. This setting allows to display all parameters on the simple operator panel (PMU) Setting the rated converter voltage and current 1. Set parameter Р = 33,3 % [Reduction of converter rated DC current (armature)] in the index 001. The value 33 % provides the decreasing of rated converter DC current according to the motor rated current. This parameter is used for the purpose of achieving a close match between the converter and motor, the converter rated DC current is reduced to the value entered here. 2. Set parameter value Р = 20 % [Reduction of converter rated DC current (field)] in the index 002. The rated current of field circuit is 20 % of rated convertor field current [4]. 17

18 Note: For thyristor convertors, which have a rated power higher that motor rated power, the following parameter values can be set in the P076: 10, 20, 33,3, 40, 50, 60, 66,6, 70, 80, 90 %. 3. Set the parameter Р = 400 V [Rated input voltage converter armature]. This is a rated voltage of on the input thyristor converter in the armature circuit. 4. Set the parameter Р = 400 V [Rated input voltage converter field]. This is a rated voltage of on the input thyristor converter in the field circuit. The rated voltage values of the power system actually used to supply the power section must be set in this parameters P (2) Setting the motor rated data 1. Set parameter Р081 = 0 [EMF-dependent field weakening]. This setting is used for control system without field-weakening mode. The rated field current is continuously applied to the field circuit. 2. Set parameter Р100 = 4,5 А [Rated motor armature current]. The rated armature current is set according to the motor rating plate. 3. Set parameter Р101 = 220 V [Rated motor armature voltage]. The rated armature voltage is set according to the motor rating plate. The one of the functions of this parameter is to determine the point at which the field-weakening mode is started. 4. Set parameter Р102 = 0,29 А [Rated motor field current]. The rated excitation current is set according to the motor rating plate. 5. Set parameter Р103 = 0,25 А [Minimum motor field current]. The parameter value P103 should be less than 0,5 Р102 to execute the optimization run for field weakening mode. In this example it is not supposed that we will work in the field weakening mode. 6. Set parameter Р109 = 0 [Control word for speed-dependent current limitation]. 0 Speed-dependent current limitation is deactivated. 1 Speeddependent current limitation is activated. The setting P109=1 is used in the two- 18

19 region speed control systems to reduce the maximal armature current in the field weakening mode. 7. Set parameter Р114 = 10 minutes [Thermal time constant of motor]. This parameter is used to protect motor from overload current in the steady-state mode. The value Р114 = 0 means that the I 2 t protection is deactivated. The motor parameters such as: P110 [Armature circuit resistance], P111 [Armature circuit inductance], P112 [Field circuit resistance], P115 [EMF at maximum speed in operation without tachometer], P118 [Rated EMF value] and P119 [Rated speed] are set automatically during the current controller optimization procedure P051= The setting of speed sensor parameters 1. Set parameter Р083 = 1 [Selection of actual speed value]. The value of this parameter is selected according to the following: 0 Actual speed value is not selected; 1 Actual speed value comes from the analog tachogenerator, which is connected to the terminals XT.103, XT.104); 2 Operation without tachogenerator (Closed EMF loop is used); 3 Actual speed value is wired up freely (selected in P609). Signal from the analog tachogenerator is displayed in the parameter r Set parameter Р741 = 30 V [Normalization for Main actual value ]. This value sets the rated voltage on the output of speed sensor under the rated motor speed. Maximum value is 270 V. 3. Set parameters P671= 1 [Source for control word 1, bit11] and P672= 1 [Source for control word 1, bit12]. The values 1 are set for bidirectional electric drive. 0 positive (P671) or negative (P672) direction of rotation is disabled. 4. Set the sign of speed signal P743= 0 [Mode of signal injection at Main actual value analog input]. The following values are used in parameter P743: 0 Injection of signal with sign; 1 Injection of absolute value of signal; 19

20 2 Injection of signal with sign, inverted; 3 Injection of absolute value of signal, inverted. The sitting P743=1 is used for non-bidirectional electric drives. The sign of actual speed can be changed by means of setting Р743= The setting of armature current ramp-function generator To limit the rate of armature current the ramp-function generator on the input of current closed loop is set by means of following parameters (see fig. 9): 1. Set parameter P157= 1 [Control word for current setpoint integrator]. Value 1 means that the ramp-function generator (RFG) acts in the current setpoint cannel. The 0 value means that the RFG is active only after the change of torque direction. 2. Set parameter P158= 0,01 sec. [Ramp-up time for current setpoint integrator]. The recommended value for older DC motors, which is not suitable for high current rates, is 0,04 sec. These two parameters allow to reduce the gearbox stressing and to protect DC motor from high armature current rates The limitation of armature current and electromagnetic torque The simplified functional diagram of torque limitation is shown on the figure 6 [5]. As can be seen from figure 7 the level of torque limitation (K0143, K0144) can be varied depending of different parameters. By means of P169 parameter the torque or current limitation is selected. The normalization of current limits (P170, P171) by means of P100 (Rated armature current) parameter is realized. From index parameters P605 and P606 comes the constant value 200 and -200 % correspondingly. Then, from current (P170, P171) and torque (P180, P181) limitations the minimal for positive torque direction or maximal for negative torque direction value is selected and comes to the nonlinear element with saturation characteristic. The binectors B0202 and B0203 set a unity value, when torque setpoint will reach positive or negative limits. 20

21 Fig. 7. Torque limitation in the Simoreg DC Master converter 1. Set parameter P169 = 1 [Select closed-loop torque / current control]. In this case the closed-loop current control with torque limitation is used. The torque limitation is a function of motor magnetic flux. In the one-region speed control system the torque limitation will corresponds to armature current limitation. 2. Set parameter P170 = 0 [Select closed-loop torque / current control]. The combination of P169 and P170 parameters set the torque or current limitation. In this case the motor torque limitation is used. The combination P169= 0 and P170= 0 set the armature current limitation and combination P169= 0 and P170= 1 set closed-loop torque control with torque limitation. 21

22 3. Set parameter P171= 150 % [System current limit in torque direction I]. The parameter value sets the armature current limitation in the positive torque direction. This value is selected according to the rated motor and thyristor convertor data. The 150 % means that the maximal armature current will not exceed the value 1,5 P100 A. Where, P100 parameter is the rated motor current. 4. Set parameter P172= -150 % [System current limit in torque direction II]. The parameter value sets the armature current limitation in the negative torque direction. 5. Set parameter P180= 150 % [Positive torque limit 1]. This parameter is used to limit the motor torque value in the positive torque direction. The value is selected according to the motor and thyristor convertor rated overload current. The 150 % means that the maximal electromagnetic torque will not exceed the value 1,5 M n. Where, M n is the rated motor torque. 6. Set parameter P181= -150 % [Negative torque limit 1]. This parameter is used to limit the motor torque value in the negative torque direction. One should add, that these parameters can be used to implement the nonreversible electric drive. For example, if we sets the parameter value P171= 0 % we don t allow electric drive to rotate in the positive direction Parameterization of ramp-function generator The simplified functional diagram of ramp-function generator (RFG) in the Simoreg DC Master is shown on the figure 8. The main parameters of first order ramp function generator are P303 Rampup time 1 and P304 Ramp-down time 1. The second order RFG is realized by setting the not zero values for parameters P305 Lower transition rounding 1 and P306 Upper transition rounding 1. The parameter P330 is used to set time of RFG in seconds (0) or in minutes (1). The parameters P307 P314 are used in some cases, where is it necessary to switch the rete of RFG during the work of electric drive. Index parameter P636 can be used to vary the rate of RFG depending on some connecter value. The default values in all indexes of P636 parameters are 100 %. 22

23 Fig. 8. Ramp function generator in the Simoreg DC Master converter 1. Set parameter P303= 10 sec [Ramp-up time 1]. The value 10 means, that electric drive will accelerate from zero to rated motor speed at 10 seconds. 2. Set parameter P304= 10 sec [Ramp-down time 1]. The value 10 means, that electric drive will decelerate from rated to zero motor speed at 10 seconds. 3. Set parameters P305= P306= 0 sec [Lower and Upper transition rounding 1]. The first order ramp-function generator is used. The ramp-up and ramp-down time of RFG is selected from the maximum acceptable value of dynamic torque during the transients Automatic parameterization of armature current closed loop The simplified functional diagram of armature current controller in the Simoreg DC Master is shown on the figure 9. 23

24 Fig. 9. Armature current controller in the Simoreg DC Master converter On the figure 9, the armature current precontrol is used to improve the performance of current closed loop in the interrupted current mode of thyristor converter. The gain k cc and time constant T cc of armature current controller are set in the parameters P155 and P156. The parameters P176 and P175 are used to vary the gain and time constant of current controller depending on some external conditions. Parameters P164 and P154 deactivate the Proportional (P) and Integral (I) components of current controller. The main parameters of armature current closed loop such as gain and time constant of current controller are adjusted during the current loop optimization procedure (P051=25). In order to make the current controller optimization it is necessary: 1. To make sure the thyristor convertor is in the ready to run operating state o7.0 or o7.1, and there are no any errors and alarms on the display on PMU. 2. Set parameter P051=25 [Key parameters Optimization run for precontrol and current controller (armature and field)]. After that, the converter switches to operating state o7.4 for several seconds and then to o7.0 or o7.1 and waits for the 24

25 input of switch-on and operating enable. The flashing of the decimal point in the operational status display on the PMU indicates that an optimization run will be performed after the switch-on command. 3. By means of switches SA6 and SA5 give commands for operation enable and switch-on. As soon as the converter reaches operating status o1.0, the optimization run is executed. The current controller optimization procedure will lasts approximately 40 seconds. The following parameters are set automatically during the optimization procedure: P110 [Armature circuit resistance], P111 [Armature circuit inductance], P112 [Field circuit resistance], P155 [Armature current controller P gain], P156 [Armature current controller reset time], P255 [Field current controller P gain], P256 [Field current controller reset time], P826 [Correction of natural commutation timing]. Attention! One must note, that if the switch-on command is not given within 30 s, this waiting status is terminated and fault message F052 displayed. After the optimization procedure the parameter P051 will be returned in the initial state P051=40 and the field current will be decreased to zero. Then, switch-off the SA5 and SA6 tumblers to the initial position Automatic parameterization of speed closed loop The simplified functional diagram of speed controller in the Simoreg DC Master is shown on the figure 10. The speed controller gain k sc and time constant T sc are set in parameters P225 and P226. The time constants of speed setpoint and feedback filters are set in parameters P228 and P

26 26 Fig. 10. Speed controller in the Simoreg DC Master converter

27 The nonlinear element with inputs P553 and P554 are used to adapt the speed controller gain and time constant to changed external conditions. The speed feedback signal can be selected from five different sources by means the P083 parameter. Also in the speed closed loop there are parameters which are responsible to stop or set the I-component of speed controller in some cases (P696, P695). The parameter P224 can be used to switch-off the integral component of speed controller and build the singleintegration automatic speed control system (P224= 0). The parameter P236 sets the performance of speed control closed loop. The main parameters of speed closed loop such as gain and time constant of speed controller are adjusted during the speed loop optimization procedure (P051= 26). To run the speed controller optimization it is necessary: 1. Set parameter P051= 26 [Key parameters - Optimization run for speed controller]. Then, by means of switches SA6 and SA5 give commands for operation enable and switch-on as in the privies chapter. The optimization process will display on the PMU by means of flashing the different numbers. During the speed controller optimization, the motor is accelerated at a maximum of 45 % of its rated armature current. The motor may reach speeds of up to approximately 20 % of maximum speed. The following parameters are set automatically during the optimization procedure: P225 [Speed controller P gain], P226 [Speed controller reset time] and P228 [Filter time for speed setpoint]. After the optimization procedure the parameter P051 will be returned in the initial state P051=40 and the field current will be decreased to zero. 2. Then, switch-off the SA5 and SA6 tumblers to the initial position. Note: The speed controller optimization run takes into account the filter of the actual speed controller value parameterized in P200. To achieve the optimum response of speed closed loop the parameter P228 is equal to P Check the value of motor maximum speed. If the maximum speed was changed during the optimization procedure more than 10 %, it is necessary to correct the speed sensor gain in the parameter P741 (for analog tachogenerator). Then, the speed loop optimization procedure should be repeated. 27

28 Note: The automatic parameterization of speed and current closed loop provides the acceptable but often not optimal transients in the speed and current control system. To adjust the optimal responses in the speed and current closed loops, the manual correction the of speed and current controller parameters with using oscilloscope is necessary. 4. Then, it is necessary to check the work of electric drive. Set the switches SA6 and SA5 to upper position and set the speed setpoint 1000 rpm be means of RP2 potentiometer. Then, to reverse the electric drive it is necessary to set the switch SA7 to upper position. To stop direct current electric drive the SA5 switch is used. The starting of electric drive and setting of speed setpoint value can be also realized by means of Drive Monitor Software. In order to start drive from the program, it is necessary to set the parameters P433= K2002 [Source for standard setpoint] and P654= K2100 [Source for control word 1, bit0]. During the work from software, the switches SA6 and SA5 must be continuously in the upper position. 3. The parameterization of thyristor converter for working in the PROFIBUS-DP network 3.1. Brief information about the PROFIBUS-DP PROFIBUS (PROcess FIeld BUS) is an open international standard of field buses with wide range of application area in the automation of technological process. Independence for different manufactures and openness of standard is guaranteed by means of international EN and IEC norms. The PROFIBUS-DP (Distributed Peripherals) is a one of communication profiles of this standard. It is optimal solution for fast and low-cost data transmission on the field level. PROFIBUS-DP predominantly utilizes the master-slave method and data is exchanged cyclically with the drives in most cases. PROFIBUS is a multi-master system and allow to work simultaneously of few automation systems, humanmachine interface systems and decentralized execution units on the one bus. 28

29 The shielded twisted pair is widely used on practice (fig. 11) and it is allow to transmit data with rates from 9,6 Kbit/sec (12 km) to 12 Mbit/sec (100 m). The transition rate depends from the distance between the two units on the bus. Fig. 11. Standard PROFIBUS-DP cable: 1 conductor А; 2 conductor В; 3 shield; 4 insolation The PROFIBUS cables have a many different implementations for specific applications. For example, there are a PROFIBUS cables for different movable units, for underground setup also there are optical cable for high data transmission rates etc. For PROFIBUS the RS485 data transmission method is used, which is based on the half-duplex, asynchronous synchronization. As a rule, the 9- pin connector is used on practice to connect the different units each other. This connector is shown on the figure 12. Fig. 12. Connector Sub-D On the Sub-D connector there is a Switch, which closes the unusable parts of the bus on the resistance. On the both ends on the bus this Switch mast be set in On position. For fail-safe operation in the network and to eliminate the hardware conflicts, it is necessary that each of all devices in the bus will have the bus access at the 29

30 appointed time. Logic bus topology in the PROFIBUS can be built on master/slave principles: master slave; master master (ring topology with marker); combination of these two principles (hybrid method). The master slave communication is a centralized one. That is, the only one master controls the access to the network and interrogates the slave devices on the bus. In this variant, the slave units cannot to transfer the data without master request and cannot by oneself to obtain admittance to the bus with some exceptions. The master master communication is a decentralized one. In this variant, there are a few master units, which are connected to the bus by means of token ring. And then, each master interrogates the specified slave units in the network. Figure 13 shows the combination of these two methods for bus access. On the figure 3 there are three master and five slave units. The master devices are serially connected to the bus by means of token ring and receive the data from slave units. Fig. 13. Hybrid method for bus access All devices in on the PROFIBUS have its own addresses in the range from 0 to 127, which allow definitely to identify the devices. The addresses are set intentionally and are independent from the physical location on the bus. The Master units are divided in the two classes: 30

31 Master (class 1) it is devices in the bus, which are usually exchanged data cyclically. Master (class 2) programmers, diagnostic devices, human-machine interface (HMI) units, etc. As a rule, they use acyclic data exchange. In some cases, they can use the cyclic data exchange. Examples of Masters (class 1) are the logical controllers Simatic S7-300, S7-400 with embedded PROFIBUS interface, or communication processors, for example CP The Masters (class 2) units are HMI panels, programs for network setting (for example STEP 7) and convertor parameterization (for example STARTER, Drive Monitor). As slave units the following devices can be used: logical controllers Simatic S7-200 and controllers S7-300 in the slave mode; communication processors, for example CP 342-5, CP 248-2; decentralized periphery ET-200; semodrive sensors; numerical program control systems Sinumeric; frequency convertors Sinamics, Micromaster etc.; the communication board CBP2 for Simoreg DC Master Converters The Simoreg DC Master convertor as a slave unit on the PROFIBUS The Simoreg DC Master acts only as a slave unit in the PROFIBUS network. To connect the Simoreg to the bus the external communication board CBP2 is used. The CBP2 communication board is mounted in the body of thyristor convertor. The optional board features three LEDs (green, yellow, red) for displaying the current operational status in the bus. The board is supplied with power via the basic unit. The optional CBP2 board features a 9-pin Sub D connector (see fig. 12) for connection to the PROFIBUS-DP system. 31

32 The bus system allows data to be exchanged very rapidly between the drives and higher-level systems (for example Simatic). The drives are accessed in the bus system according to the master/slave principle. The drives are always slaves. Each slave is uniquely identified by a slave address, which can be set by means of parameter. Data are exchanged in message frames. Each message frame contains useful data which are divided into two groups: 1. Parameters (parameter identifier value, PKW). 2. Process data (PZD). The PKW area contains all transfer data which are needed to read or write parameter values or read parameter properties. The PZD area contains all the information needed to control a variable-speed drive. Control information (control words) and setpoints are passed to the slaves by the PROFIBUS-DP master. Information about the status of slaves (status words) as well as actual values are transferred in the opposite direction. The length of the PKW and PZD components in the message frame are determined by the master. Only the bus address and, if necessary, the message frame are set on the slaves. The simplified structure of PKW and PZD areas is shown on the fig 14. Fig. 14. Structure of data transmission telegram Let s consider the communication between the Simoreg DC Master Converter and PLC. The communication between the thyristor converter and PLC is realized by means of PROFIdrive profile in the electric drive. The drive profile selection is made in the STEP 7 program during the hardware configuration. 32

33 The PROFIdrive profile (PRO), which is used in the Simoreg converter is shown on the figure 15. Fig. 15. Telegram types in the Simoreg DC Master Converter In the second version of PROFIdrive protocol there are a five telegram types (PRO), which are depicted on the figure. 15. As can be seen from the figure, the most simple is a PRO3 profile, which is able to start, stop and reverse electric drive and regulate the motor speed by means of Control word 1 (STW1) and Speed setpoint signal (Main setpoint) (HSW). Control word 1 and the Speed setpoint signals are the 16-bit signals, which are receiver from master unit. In response to master request, the Simoreg DC Master sends the Status word (ZSW1) and actual speed signal (HIM). This signal can be used in the PLC to control the electric drive operation. There are no the parameter changing mechanism in the PRO3 telegram. If there is a need to change converter parameters via PROFIBUS, it is necessary to select PRO1 or PRO2 profile. In the PRO2 profile also it is possible to send and receive different variables from or to PLC. The variable choosing is made by means of some parameters, which will describe below. For example, it is possible to send to the PLC the faults codes, actual armature current or motor electromagnetic torque etc. Also it 33

34 is possible to receive from PLC the Control word 2 (STW2) and use this word for controlling of electric drive. The PRO5 telegram allow to fully free adjusting of sanded and received data between the Simoreg converter and PL, but one should add that without Control word 1 and Speed setpoint signals. 3.3 Control and Status words and speed setpoint signal The PRO3 profile in the Simoreg converter is the most simple for controlling the electric drive via PROFIBUS-DP. Control word 1 is a 16-bit signal, where each bit has some specific function, such as: start, stop or reverse of electric drive. Let s consider how we can to control of electric drive via Control word 1, which is shown in the table 4. Control word 1 for Simoreg DC Master Converter Table 4 Bit Value Function Description ON. Turn electric drive into the ready to run state. 0 OFF 1 Off 1 stopping by means of ramp-function generator. 1 Operating 1 condition 0 OFF2 Off 2 Instantaneous pulse disable, drive coasts to a standstill. 1 Operating 2 condition 0 OFF3 Off 3 Rapid stop: Shutdown with the fastest possible acceleration rate. 1 Enable Closed-loop control and pulses are enabled. 3 operation 0 Disable Closed-loop control and pulses are disabled. operation 1 Operating 4 condition 0 Disable RFG Output of RFG is set to 0 (the fastest possible braking operation), converter remains in the ON state. 34

35 Table 4. Continuation Enable RFG Ramp-function generator start. 0 Stop RFG Setpoint currently supplied by the RFG is frozen. 6 1 Enable setpoint Value selected at the RFG input is activated. 0 Disable setpoint Value selected at the RFG input is set to 0. 1 Fault Fault is acknowledged by a positive edge, Simoreg then 7 acknowledge switches to starting lockout state CW inching Clockwise rotation of electric drive CCW inching Counterclockwise rotation of electric drive Control by PLC No control by Master transfers valid setpoint. There is no setpoint from master. PLC 11 1 Enable positive direction of rotation The positive direction of rotation is allowed. 0 Positive The positive direction of rotation is not allowed. direction of rotation disable 12 1 Enable negative direction of rotation The negative direction of rotation is allowed. 0 Negative direction of rotation disable The negative direction of rotation is not allowed MOP UP Motor potentiometer UP MOP DOWN Motor potentiometer DOWN External fault No external fault Fault signal from PLC (F021). No fault signal. Let s consider some examples of Control word 1 for the most common command, which is shown in the table 5. To simplify the Control word 1 recording format it is useful to use the hexadecimal format (Hex). 35

36 Command Examples of Control word 1 Control word in the binary format (bit numbers) Table 5 Control word in the hexadecimal format Ready to run (Stop) C7E Start forward C7F Start backward (reverse) F Fault reset CFE Before the starting of electric drive, it is necessary to prepare the Simoreg convertor to operation. For this you need to send the 1C7E (hex) value from the PLC to the Control word 1 area into converter. Then, the starting command 1C7F should be sent in the Control word 1 area. If the speed setpoint is not equal to zero, the electric drive will starts rotation. The Speed setpoint signal (Main setpoint) also consists of 16 bits as and Control word. The 100 % of speed setpoint corresponds to the 4000 (hex) value by default. This value is a 2 14, that is the rated motor speed (100 %) uses the 14 bits of the word. So, the maximum speed setpoint value is a 200 % taking into account that the high bit of word is used for speed setpoint sign. To convert of speed setpoint from percent to the hex value it is useful to use the intermediate values in the decimal format. The some examples of speed setpoint values in the percent, hex and decimal formats are shown in the table 6. Speed setpoint examples Speed setpoint value, % Speed setpoint value, (dec) Speed setpoint value, (hex) CCC Table 6 The using of Control word 1 and Speed setpoint signal are enough to control the DC electric drive via PROFIBUS. 36

37 But for reliable operation of electric drive it is necessary to receive from convertor the signals: Ready to run, Faults, Alarms, Operation mode etc. This is done by means of Status word, which is shown in detail in the table 7. Status word 1 of Simoreg DC Master Converter 37 Table 7 Bit Value Function Description Ready for switch ON Power supply switched on, electronics initialized, pulses disabled. 0 Not ready for switch ON 1 Ready to run Converter is switched on (ON command is applied), no fault is active, inverter can start when Enable 1 operation command is issued. 0 Not ready to run Causes: No ON command, fault, OFF2 or OFF3 command, starting lockout. 1 Operation Drive is ruining (See control word, bit 3). 2 enabled 0 Operation Pulses disabled. disabled 1 Fault is active Fault, see fault parameter r0947. Drive is faulty and thus 3 inoperative. It switches to starting lockout state after 0 successful correction and acknowledgement of fault OFF2 command applied OFF3 command applied Switch on inhibit No switch on inhibit Alarm is active No setpoint /act.val. deviation Setpoint/act.val. deviation PZD control - See control word, bit 1 (table 4). See control word, bit 2 (table 4). Drive can be restarted only by OFF1 followed by ON. Alarm, see alarm parameter r2110. Drive still in operation. Setpoint/actual value deviation within tolerance range. PZD control requested (always 1)

38 Table 7. Continuation Max. speed Motor actual speed is higher or equal to the maximum 10 reached speed P373 0 Max. speed not reached 11 1 Undervoltage Undervoltage fault (F006) is active. 0 No undervoltage No undervoltage fault is active 1 Main contactor Request to energize main contactor. 12 request 0 No contactor No request to energize main contactor. request 13 1 RFG active Ramp-function generator is active. 0 RFG not active Ramp-function generator is not active. 1 Positive speed Clockwise rotation of electric drive. 14 setpoint 0 Negative speed Counterclockwise rotation of electric drive. setpoint 15 1 Spare Not used 0 The Actual speed signal uses the same format as a Speed setpoint and also can be sanded to the PLC via the PROFIBUS. Some examples of Status word 1 in the Simoreg DC Master converter are shown in the table 8. State Status word 1 examples Status word in the decimal format (bit numbers) Table 8 Status word in the hexadecimal format (hex) Ready to run (Stop) Run forward Run backward Fault signal One should add, that to control the frequency convertors such as Micromaster and Sinamics via PROFIBUS-DP same principles are used. 38

39 3.4. The using of PKW mechanism for processing parameters The PKW mechanism is used to read and write parameters of Simoreg converter via the PROFIBUS network. This mechanism can use both acyclic and cyclic data transfer. To access the reading or writing of converter parameters it is necessary to select the profile PRO1 or PRO2 (see figure 15) during the hardware configuration in the STEP 7 program [2]. The parameter area for PKW mechanism always consists of 4 words. Structure of this area is shown on the figure 16. Fig. 16. Parameter area of PKW mechanism Let s consider the all three part of parameters area separately. First word consists of 16 bits and is used for parameter identifier (PKE). The parameter identifier (PKE) contains the number of the relevant parameter and an identifier which determines the action to be taken. Structure of parameter identifier is depicted on the figure 17. Рис. 17. The word structure of parameter identifier area The parameter identifier (PKE) consists of following areas: Bits from 0 to 10 are used for parameter number (PNU parameter number). The maximum parameter number is 2048 (2 11 ), therefore to access to parameter numbers more than 2000 the additional offset displacement in the index area (IND) is set; 39

40 Bit 11 (SPM) is reserved and its value always equal to zero; Bits 12 to 15 (AK) contain the request or the response identifier. The meaning of the request identifier for request telegrams (master converter) is shown in table 9. Table 9 Request identifier Request identifier (master converter) Functions No request Request parameter value Modify parameter value (word) Modify parameter value (double word) Request descriptive element 1 Request parameter value (array) Modify parameter value (array, word) Modify parameter value (array, double word) Request number of array elements Response identifier positive negative 0 7 or 8 1 or 2 7 or or or or 8 4 or 5 7 or or or or 8 For example, to change parameter P303 [Ramp-up time] we should set the parameter number ( ) in the PNU area and send request (10 2) to the AK area. If the parameter changing passed without any errors that the in response we will have the number 2 response identifier. If there is some error during the parameter changing, in response we will have the numbers 7 or 8 response identifiers. The meaning of response identifiers is shown in the table 10. Table 10 Response identifier (inverter master) Response identifier Functions No response Transfer parameter value (word) Transfer parameter value (double word) Transfer descriptive element 1 Transfer parameter value (array word) 2 Transfer parameter value (array double word) 2 Transfer number of array elements Cannot process request (with error number) No master control status for PKW interface Positive responses Negative responses

41 If the response identifier is 7 (cannot process request), then one of the fault numbers will be stored in parameter value 2 (PWE2) [2]. The second word in the parameter area (PKW) is a parameter index. The structure of this word depends of data transferring types (cyclic or acyclic). On the figure 18 the structure of parameter index for these two data transfer types is shown. a) Cyclic data transferb) Acyclic data transfer Fig. 18. Structure of parameter index (IND) As can be seen from the figure 18, that main different is that the subindex and parameter page selection is interchanged. Let s consider the cyclic data transfer between the PLC and Simoreg converter. The convertor has index parameters. The index can be switched by means of bits 16 and 17 of Control word 2 [5]. The master can request to the different parameter index (subindex) by means of PROFIBUS network. Parameter subindex occupies a high 8 bits of IND and can take values from 0 to 255 (2 8 ). The page parameter selection is used for the accessing to the parameters, which number are higher than In the Simoreg DC Master there are no parameters numbers higher than 2000, so the page parameter selection mechanism is not considered here. 41

42 The parameter value is set in the PWE area, which consists of two words. The 32-bit value is transferred through the high word PWE1 and the lower word PWE2. As to the 16-bit values, they are transferred by means of PWE2 word, the PWE1 word is not used in this case. The parameter values area is shown on the figure 19. Fig. 19. Parameter values area During the work with convertor parameters via PROFIBUS it is necessary to observe the following conditions: A request or a response can only ever refer to one parameter. The master must repeat a request continuously until it has received the appropriate response. The complete request must be sent in one telegram. Request telegrams cannot be split. The same rule applies to responses. In the case of response telegrams which contain parameter values, the drive always returns the momentary parameter value when repeating response telegrams. If no information needs to be fetched from the PKW interface in cyclical operation (only PZD data are relevant), then the "No request" request telegram must be issued. Let consider some examples of parameter requesting, which are shown in the table

43 Description Reading Р0303 Reading Р0304 Writing Р0303 Evaluating an error response The examples of using PKW mechanism PKW (hex format) PKE IND PWE Comments Request 112F Р0303 rump-up time (10 sec Response 112F bit IEEE float point). Table 11 Request Р0304 rump-down time (10 sec Response bit IEEE float point). Request 212F Р0303 rump-up time (2 sec 4000 Response 212F bit IEEE float point). Request 212F Fault drive is in operation mode. Response 712F Parameter changing is not allowed. One should add, that the program in STEP7 for parameter changing is not describer here. For more detail information see [2] The parameterization of Simoreg convertor for working from PROFIBUS-DP Let s consider the most important communication parameters of Simoreg DC master converter: 1. Parameter U712 [PRO type] defines of the number of words in the parameter and process data section of the telegram (required only if the PPO type cannot be set via PROFIBUSDP master). So it is not necessary to set this value. 2. Parameter U722 [Telegram failure time for process data (0 = deactivated)]. If this monitoring function is activated, the DP master passes a time value (watchdog time) to the slave when the link is set up. If no data are exchanged within this period, the slave terminates the process data exchange with the SIMOREG converter. The latter can monitor the process data as a function of U722 and activate fault message F P918 [Bus address]. It is necessary to set this value from 0 to 127 according to the STEP7 hardware configuration. 4. P927 [Parameterization enable]. Parameter should be set if parameters are to be assigned via PROFIBUS with using PKW mechanism. 43

44 The data exchange between the Simoreg DC Master and communication board CBP2 is shown on the figure 20. As can be seen from the figure, the control word 1 and speed setpoint receive from the board to the connectors K3001 and K3002. The connector K3001 (Control word 1) can be divided into the individual bits, which are used to send commands start, stop, fault acknowledge and reverse to electric drive. By means of parameter U734 the variables, which should be sent from the electric drive to PLC is selected. By default the Status word 1 and Actual speed is sent. Fig. 20. Data exchange between Simoreg and technological board CBP2 So, to control electric drive from PROFIBUS it is necessary to set the following parameters: 5. Set parameter P433=K3002 [Source for standard setpoint]. This parameter applies the Speed setpoint signal to the thyristor converter. 44

45 6. Set parameter P648=K3001 [Source for control word 1]. This setting allow to setup commands (start, stop, fault acknowledge and reverse etc.) from the PROFIBUS network (see tables 4, 5). One should add, during the work from PROFIBUS-DP, the switches SA6 and SA5 must be continuously in the upper position. 3. THE PLOTTING OF TRANSIENTS OSCILLOGRAMS WITH USING THE DRIVE MONITOR SOFTWARE For Simoreg DC Master Convertor in the Drive Monitor Software there is a function of transients building. To turn program in the transient building mode, it is necessary to press the button or - Trace in the program window. After that, the Drive Monitor windows will looks like in the figure 21. Fig. 21. Drive Monitor window in the transients building mode 45

46 The buttons assignment of the Drive Monitor in the transients building mode (see fig.21): variable. variable. Y axis: gain up increases the scale of the 0Y axis for selected Y axis: gain down decreases the scale of the 0Y axis for selected Y axis: automatic scaling sets the automatic scale of the 0Y axis for selected variable. Min- And Max- marker On/Off shows the markers for maximum and minimum values for selected variable. General Settings shows the setting window of main setting for external view of transients building. Open trace file opens the file with saved transients. Save trace file saves the transients oscillogram in the files with the following extensions: *.trс, *.txt, *.wmt. Show Record info shows the information about the oscillogram recording settings. Copy traces to clipboard copies the oscillogram to the clipboard in the graphic format with white background. The information about markers is not saved. Show ASCII list of waveform data shows the oscillogram points in the text format. Print all visable traces prints the visable transients graphics. Help; about trace shows information about the transients recording in the Drive Monitor program. In the field dt the time difference between the two cursors is displaed, in the fied dv the amplitude difference beetwin the two cursors for selected variable is displaed. And the show the 46

47 current time position for selected cursor with respect to trigger time and amplitude of slected varible. Immidiate starts of transients recording. Starts transients recording acording to the trigger settings. Read recorded data fron convertot to PC. recording (see fig. 22). Shows the windows with main settings of transients Fig. 22. The windows of transients recording settings In the lift part of setting windows (fig. 22) the displayed variables is selected. The most important connectors for different variables are shown in the table

48 Table 12 Connector number К0117 К0142 К0167 К0170 К0287 К0290 The connector for displaying different variables Connector description Motor armature current Motor electromagnetic torque Speed actual value Speed setpoint value Motor EMF value Motor magnetic flux One should add, that the all connector from functional diagram mentioned below (fig. 7-10) can be displayed on the trace by selecting the appropriate connectors in the trace setting window. In the right part of setting window in the fields of recording settings the recording interval and pretrigger values are set. Recording interval sets the time for transients recording. Default value is 1 66,7/50=1,33 sec. After that time will be exceed, the transient recording will be stopped. Pretrigger sets the value on the 0X axis when the trigger condition is executed. To put in other words, it is a time in percent of Recording interval, which is recorded before the trigger conditions occurred. The using of trigger allows users to start recording of transients according with different external condition. In the channel field the some variable is selected. This value is compared to the value in the field Trigger value. And if value of this variable will exceed (Trigger conditions - >) the trigger value the run of transients recording will be started. The trigger mode of transients recording is switched-on by means of Start button. The Go button is used for immediate starts of transients recording and trigger setting in this case is not work. To stop the transients recording, it is necessary to press the Stop button. The using of Start button is more preferable on practice because off in this case the transients recording are realized automatically by means of some external 48

49 conditions. The binectors values can be also displayed on the trace window by means of BiCo conversion button. It is also possible to start transients recording when the fault of thyristor convertor is occurred. The selected variable and recording settings can be saved in special file be means of save file button. To load this file the load file button is used. Attention! During the transients recording it is necessary to watch that the scales of all variables in the trace window are the same. In this case there are no problems with different scales for different variables. In conclusion, one should add, that the Trace function in the Drive Monitor Software is a powerful instrument for recording the different transients in the DC electric drives. 49

50 GLOSSARY 1. Automatic Control System (Автоматическая система управления) is the system that can control a plant (such as a direct current motor or some technological process) by using the different controllers without human. Automation control systems allow to reduce the need for human work in the technological complexes. 2. Block Diagram (Functional diagram) (Функциональная схема) is a schematic representation of control system, on which the transition or transfer functions are represented by blocks connected by lines, which show the relationships of the different blocks. 3. Closed Loop Control System (Замкнутая система автоматического управления) a closed system with feedback or feedforward. 4. Closed Loop Transfer Function (Передаточная функция замкнутого контура) is a mathematical expression of transfer function describing the closed loop control system. 5. Current Controller (Регулятор тока) is a device or program algorithm to control the motor armature current in closed loop control system with current negative feedback. 6. Digital Control System (Цифровая система управления) is a control system implemented on special microcontroller which acts as system controllers. Digital controller is a discrete unit thus the Laplace transform is replaced with the Z-transform. Digital microcontroller also needs some additional device such as analog-to-digital and digital-to-analog convertors. 7. Direct Current Motor (Двигатель постоянного тока) is an electrical machine designed to be run from a direct current power source. 8. Disturbance action (Возмущающее воздействие) is a temporary change in average environmental conditions that causes a pronounced change in the 50

51 control system output. Outside disturbance for control system often is a load torque on the electric motor shaft. 9. Electric Drive (Электропривод) is electro mechanical system that converts electrical to mechanical energy. 10. Electromagnetic Torque (Электромагнитный момент) also called electromagnetic moment or moment of force, is the tendency of a force to rotate an electric motor rotor about a shaft axis. 11. Feedback (Обратная связь) the output signal of the plant sensor (speed, current, position) is closed into control system as an input usually with negative sign. 12. Filter (Фильтр) hardware or software device in control system intends to reject different perturbation like noise and oscillations. 13. Frequency Response (Частотная характеристика) the control system or plant response to sinusoidal signals of different frequencies. Frequency response is the measure of any system's output spectrum in response to an input signal. 14. Integrator (I-controller) (Интегратор, И-регулятор) hardware or software device in control system that has the effect of integrating the input signal. 15. Magnetic Flux (Магнитный поток) is a measure of the amount of magnetic field passing through a given surface. 16. Modular Optimum (Модульный оптимум) optimal method for controller adjustment which provides a non-oscillatory closed-loop response with small overshoot for different closed loops. 17. MATLAB commercial software having a Simulink toolbox which used for simulation study of plant and control systems. 18. Microprocessor control system (Микропроцессорная система управления) The automatic control system which is implemented on the microprocessor. 51

52 19. Negative Feedback (Отрицательная обратная связь) a feedback system where the plant output signal is subtracted from the input signal and the difference is input to the control system. 20. Open Loop Control System (Разомкнутая система управления) when the system is not closed, its behavior has a control error under different disturbance in spite of using controllers. 21. Optimal Control (Оптимальное управление) a branch of control engineering that deals with the minimization of different criterions, or maximization of system performance. 22. Order (Порядок) the order of a polynomial is the highest exponent degree of the variable in the characteristic equation. The order of a control system is the order of the denominator polynomial of transfer function. 23. Oscillations (Колебания) is the variation of different physical variables, typically in time, about a mean value. Oscillations often occur in control systems during sensors scanning (for example: current or speed sensors). 24. Overshoot (Перерегулирование) is when an output signal of loop or control system exceeds its steady-state value of several per cent. It appears especially in the step response of bandlimited control systems. 25. Proportional-integral-derivative Controller (PID controller) (ПИДрегулятор) is a fundamental control loop feedback controller widely used in industrial control systems. The PID controller is the most commonly used algorithm in electric drive control system. A PID controller calculates an error as the difference between a measured process variable and a desired setpoint. The controller tends to minimize the error by adjusting the controller output variable. The P- and PI-controller are the special cases of PID-controller. 26. PROFIBUS (PROcess FIeld BUS) is an open international standard of field buses with wide range of application area in the automation of technological process. 52

53 27. Positive Feedback (Положительная обратная связь) a feedback system where the plant output signal is added to the system input, and the sum is input into the control system. 28. Ramp-function generator (Задатчик интенсивности) is the nonlinear device that is mounted in the setpoint cannel of controlled variables and its aim is to limit the rate of setpoint signal in input of automatic control system. 29. Symmetric Optimum (Симметричный оптимум) optimal method for controller adjustment, which provides a symmetric logarithmical frequency response with respect to cutoff frequency. Closed loop control response in such systems has overshoot value about 50 percent. 30. Speed Controller (Регулятор скорости) is a device or program algorithm to control the motor angular speed in closed loop control system with speed negative feedback. 31. Stability (Устойчивость) is a feature of control system to return to initial condition after applying of different disturbances. 32. Step Response (Реакция на ступенчатое воздействие) describes the reaction of a system as a function of time in response to unit-step input signal. 33. Steady State Error (Установившаяся ошибка) at steady state, the amount by which the system output value differs from the reference value (examples: speed error, armature current error). 34. Subsequent coordinate control (Подчиненное регулирование координат) is fundamental prince of automatic control theory and is widely used in automatic control system of electric drives. According to this principle the control systems are engineered in view of multiloop control systems in which each inner loop is subordinated to output loop. 35. Thyristor Power Converter (Силовой тиристорный преобразователь) is used in direct current electric drives to create a DC variable voltage from AC power supply. 53

54 36. Transfer Function (Передаточная функция) the ratio of the system output to its input, in the P-domain. The Laplace Transform of the function's impulse response. 37. Transient (Переходный процесс) is the response of a system to a change from equilibrium. 38. Unity Feedback (Единичная обратная связь) a feedback system where the feedback loop element has a transfer function equal to 1. 54

55 REFERENCES 1. Шрейнер Р. Т. Системы подчиненного регулирования электроприводов [Текст]: учеб. пособие / Р. Т. Шрейнер. Екатеринбург: Изд-во ГОУ ВПО «Рос. гос. проф.-пед. ун-т», с. 2. Системы управления электроприводами переменного тока. Управление электроприводами по сети PROFIBUS [Текст]: учебнометодическое пособие / Ю. В. Плотников, В. Н. Поляков. Екатеринбург: УрФУ, с. 3. Терехов В. М. Системы управления электроприводов [Текст]: учебник для студ. высш. учеб. заведений/ В.М. Терехов, О.И. Осипов; под ред. В.М. Терехова. - 2-е изд., стер. - М.: Издательский центр Академия, с. 4. ELECTRIC DRIVE CONTROL SYSTEM (SIMOREG DC MASTER) [Text]: Methodological course book for laboratory work of «Electric Drive Control System» discipline. / author Y.V. Plotnikov. Ekaterinburg: Ural Federal University, p. 5. SIMOREG DC-MASTER. Operating Instructions for Microprocessor- Based Converters from 6kW to 2500kW for Variable-Speed DC Drives [Text]. Siemens p. 6. SIMOREG DC Master 6RA70. Series Tips on Configuration, Hardware, Software, and Closed-Loop Control [Text]. Converters with microprocessor from 6kW to 1900kW for variable-speed DC drives. Siemens p. 55

56 Electronic textbook Plotnikov Yuriy Valerievich ELECTRIC DRIVE CONTROL SYSTEMS (Parameterization of Thyristor Converters SIMOREG DC MASTER) Preparing for publication Computer make-up N.V. Lutova Y. V. Plotnikov Recommended by Methodic union Allow to publication Date of publication Electronic format pdf Size 2,95 p , Yekaterinburg, Mira street, 19 Data portal YrFU 56