CN102591319A - Test device and test method for STATCOM (Static Synchronous Compensator) controller - Google Patents

Abstract

The invention provides a test device and a test method for an STATCOM (Static Synchronous Compensator) controller and belongs to the technical field of reactive compensation. The test device comprises a system power supply, a transformer, a voltage disturbing generation device, a switch circuit, a test main circuit and a control protection system, wherein the system power supply, the transformer, the switch circuit and the test main circuit are sequentially connected in series; and the voltage disturbing generation device is connected with the transformer in parallel. The test device has the advantages of dynamic continuous reactive compensation, high adjustment speed, wide adjustment range, strong undervoltage reactive adjusting capability, low harmonic content, no resonance for accessing a power system. The test method is simple and reliable; and according to the test method, various work conditions of faults of the power system can be constructed and the test verification requirement on an STATCOM control strategy is met.

Description

A test device and method for STATCOM controller

technical field

The invention belongs to the technical field of reactive power compensation, and in particular relates to a test device and method for a STATCOM controller.

Background technique

At present, most of the simulation technology is used to establish the model of the control system to verify the feasibility and correctness of the designed control strategy. Although it can provide a certain reference for the development of the control system, it cannot test the controller and cannot reflect the actual situation of the system. Working conditions, lack of experimental basis. There are also real-time digital simulation technology to establish a system model to verify the designed controller and control strategy. For example, the real-time digital simulator RTDS (Real Time Digital Simulator) developed by Canada, HYPERSIM developed by Canadian TEQSM company, and ARENE developed by Electric Power Company of France, etc. On the one hand, the cost of real-time digital simulation equipment is usually high; The static synchronous compensator usually has many series stages, the control signals of each chain link are different, and the interface circuit between the equipment, the controller and the static synchronous compensator is relatively complicated. All of these limit the application of real-time digital simulation technology in chain static synchronous compensator.

Static Synchronous Compensator STATCOM (Static Synchronous Compensator) is a new type of static var dynamic compensation device, which is composed of voltage source converters connected in parallel to the system, and its output capacitive or inductive reactive current is continuous, adjustable and Independent of the voltage at the point of connection to the system. It takes the voltage source converter VSC as the core, uses DC capacitors as energy storage components on the DC side, and uses turn-off devices to convert the DC side voltage into an AC voltage with the same frequency as the power grid, and connects the reactor in parallel to the power grid. , Properly adjusting the amplitude and phase of the output voltage on the AC side, or directly controlling the current on the AC side, can make the device absorb or send out reactive current that meets the requirements, and realize the purpose of dynamic reactive power compensation. When only the fundamental frequency is considered, STATCOM can be equivalently regarded as an AC voltage source with the same frequency as the power grid whose amplitude and phase can be controlled.

By configuring different control strategies, the STATCOM device can play an important role in maintaining or controlling the node voltage, improving the transmission capacity of the line, damping power oscillation, and improving the static and transient stability of the system; , the static and transient processes of the power system will affect the operation of STATCOM to varying degrees, especially in the case of system faults, the operating conditions of STATCOM will change suddenly. At this time, the safety of STATCOM itself should be considered first, followed by its function; therefore, it is necessary to consider not only the control of the device itself, but also the control of the system, and design different levels of control strategies to improve the safety of the STATCOM device. Survivability, and to avoid the disturbance caused by the exit of the device to the system, its control strategy is mainly divided into system level, device level and bottom layer control.

System-level control strategies are mainly divided into steady-state control mode and transient control mode. Steady-state control mode is divided into constant reactive power mode and constant voltage mode. Under the condition of constant reactive power operation, STATCOM will output constant reactive power, and the target value of reactive power output can be set between rated capacitive reactive power and rated inductive reactive power; The goal is to stabilize the system voltage, and automatically adjust the reactive power output by the device.

The transient control mode is to construct various faults inside STATCOM, swells, sags, single-phase, two-phase, and three-phase faults of the system side voltage under transient conditions to verify the controller and control strategy.

In order to ensure the feasibility and correctness of the designed control strategy, it is necessary to take corresponding means to test. At present, commonly used simulation software establishes the model of the control system to verify whether the designed control strategy is feasible. This method can provide a certain reference and guidance for the development of the control system, but it cannot reflect the actual working conditions of the system and lacks certain experimental basis.

Contents of the invention

In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a test device and method for STATCOM controller; the test device has dynamic continuous reactive power compensation, fast adjustment speed, wide adjustment range, and strong reactive power adjustment ability under undervoltage , Low harmonic content, no resonance when connected to the power system, simple and reliable test method, can construct various power system fault conditions, and meet the test verification requirements for STATCOM control strategies.

In order to realize the foregoing invention object, the present invention adopts following technical scheme:

A kind of test device for STATCOM controller, described test device comprises system power supply, comprises power supply, system impedance and contactor, is used to supply power to described test device; The device voltage is matched; the voltage disturbance generating device is used to construct the voltage of the test main circuit access point; the switch circuit is used to realize the test main circuit access and exit; the control protection system is used to control and protect the entire device operation and operation; and test main circuit for testing the operation logic of STATCOM.

The system power supply, transformer, switch circuit and test main circuit are connected in series in sequence, the input side of the voltage disturbance generating device is connected in parallel with the output terminal of the system power supply, and the output side is connected in series between the transformer and the switch circuit.

The voltage disturbance generator includes a start switch QF2, a soft start circuit, a three-phase rectifier transformer, a three-phase back-to-back converter and a three-phase filter circuit.

The soft-start circuit includes a soft-start resistor R4 and a bypass switch QF4 connected in parallel thereto.

The three-phase rectifier transformer is a multi-winding transformer, and the multi-winding transformer is a three-phase independent transformer or a three-phase integrated transformer; the input end of each phase back-to-back converter is connected to the output end of each phase rectifier transformer, and its output end is connected to the output end of each phase rectifier transformer. Each phase filter circuit is connected.

The filter circuit for each phase includes an inductor, a resistor and a capacitor. The resistor and capacitor are connected in series and parallel to the output end of the voltage disturbance generating device, and the inductor is connected in series with the output end of the voltage disturbance generating device.

The switching circuit includes a lightning arrester F, a fuse FU2, a voltage transformer and a switch QF1; the lightning arrester F is used for overvoltage protection of the test main circuit.

The test main circuit includes current transformers, reactors, soft starting circuits and cascaded H-type chain links connected in series in sequence;

The current transformer is used to detect current;

The reactor is used to suppress the high-order harmonic current generated by the H-type chain link;

The DC capacitance of the H-shaped chain link plays a role of voltage support.

The soft-start circuit includes a soft-start resistor and a bypass switch connected in parallel therewith.

The control and protection system includes a background workstation, a communication management machine, an on-site monitoring system, a controller, a three-phase commutation chain phase control unit and a three-phase commutation chain unit controller.

The test device realizes that the voltage disturbance generating device exits the test device by connecting a bypass switch in parallel at the output end of the voltage disturbance generating device or through the zero voltage output of each phase back-to-back converter.

A test method for a STATCOM controller, said test method comprising the steps of:

(1) closing the circuit breaker QZ of the system power supply;

(2) closing the start switch QF2;

(3) the soft starting resistor charges the DC capacitor in the three-phase back-to-back converter;

(4) After the DC capacitor reaches a steady state, close the bypass switch QF4 of the soft starting circuit;

(5) Closing the switch QF1, the main circuit of the test charges the DC bus of each link through the soft starting resistor;

(6) After the charging is stable, close the bypass switch of the test main circuit to bypass the soft starting resistor, and control each chain link to output PWM pulse;

(7) Control the output voltage of the test main circuit to be in phase with the voltage at the access point of the test main circuit, and put the test main circuit into normal operation;

(8) Controlling the three-phase back-to-back converter to output an inverter voltage whose amplitude and phase change are superimposed in the test main circuit;

(9) Simulate various faults of the power system;

(10) Verify the transient control strategy of the STATCOM controller.

Compared with the prior art, the beneficial effects of the present invention are:

1. The test device has dynamic continuous reactive power compensation, fast adjustment speed, wide adjustment range, strong reactive power adjustment ability under undervoltage, low harmonic content, and no resonance when connected to the power system;

2. The test method is simple and reliable, and can construct various power system fault conditions to meet the test verification requirements for STATCOM control;

3. The test method solves the difficult problem of control test and provides the basis and reference for the development of STATCOM controller.

Description of drawings

Figure 1 is the overall frame diagram of the control and protection system;

Figure 2 is a circuit diagram of the test main circuit and switch circuit;

Figure 3 is the overall structure diagram of the test device.

Detailed ways

Static var compensator STATCOM has various advantages such as fast reactive power adjustment speed, wide adjustment range, strong reactive power adjustment ability under undervoltage conditions, low harmonic content, small footprint, and no resonance in the access system. It can play an important role in maintaining or controlling node voltage, improving line transmission capacity, damping power oscillation, and improving the static and transient stability of the system.

In order to realize the function of the static var compensator STATCOM, it is necessary to configure a fully functional, stable and reliable control and protection system, as shown in Figure 1. The control and protection system includes a background workstation, a communication management machine, an on-site monitoring system, a controller, and a three-phase Converter chain phase control unit and three-phase converter chain unit controller; the controller has the functions of sampling, control and protection, wave recording, timing, input and output, and communication. The phase control unit of the three-phase commutation chain has a communication function, and completes the STATCOM adjustment and protection function of each phase and the data transmission with all unit controllers of the phase. The communication network is used for the communication between the man-machine interface and each control unit, to complete the SOE transmission, the fixed value parameter and the operation mode distribution, the transmission of the recorded wave data, etc. The communication management machine is used for protocol conversion to realize communication with the background. There are hard blockade and hard interrupt request optical fibers between the controller and the phase control unit and between the phase control units, which are used to quickly block the three phases after a fault.

As shown in Fig. 2, the switch circuit includes a lightning arrester F, a fuse FU2, a voltage transformer and a switch QF1; the lightning arrester F is used for overvoltage protection of the test main circuit.

The test main circuit includes current transformers, reactors, soft starting circuits and cascaded H-type chain links connected in series in sequence;

The current transformer is used to detect current;

The reactor is used to suppress the high-order harmonic current generated by the H-type chain link;

The DC capacitance of the H-shaped chain link plays a role of voltage support.

The soft-start circuit includes a soft-start resistor and a bypass switch connected in parallel therewith.

As shown in Fig. 3, a kind of test device for STATCOM controller, described test device comprises system power supply, comprises power supply, system impedance and contactor, is used to supply power to described test device; The system voltage matches the test device voltage; the voltage disturbance generating device is used to construct the voltage of the test main circuit access point; the switch circuit is used to realize the test main circuit access and exit; the control protection system is used to control and To protect the operation and operation of the whole device; and to test the main circuit for testing the operation logic of the STATCOM.

The system power supply, transformer, switch circuit and test main circuit are connected in series in sequence, the input side of the voltage disturbance generating device is connected in parallel with the output terminal of the system power supply, and the output side is connected in series between the transformer and the switch circuit.

The voltage disturbance generator includes a start switch QF2, a soft start circuit, a three-phase rectifier transformer, a three-phase back-to-back converter and a three-phase filter circuit.

The soft-start circuit includes a soft-start resistor R4 and a bypass switch QF4 connected in parallel thereto.

The three-phase rectifier transformer is a multi-winding transformer, and the multi-winding transformer is a three-phase independent transformer or a three-phase integrated transformer; the input end of each phase back-to-back converter is connected to the output end of each phase rectifier transformer, and its output end is connected to the output end of each phase rectifier transformer. Each phase filter circuit is connected.

The filter circuit for each phase includes an inductor, a resistor and a capacitor. The resistor and capacitor are connected in series and parallel to the output end of the voltage disturbance generating device, and the inductor is connected in series with the output end of the voltage disturbance generating device.

Closing the bypass switches A, B and C connected in parallel with the output terminal of the voltage disturbance generating device or passing through the zero voltage output of each phase back-to-back converter realizes that the voltage disturbance generating device exits the test device.

A test method for a STATCOM controller, said test method comprising the steps of:

(1) closing the circuit breaker QZ of the system power supply;

(2) closing the start switch QF2;

(3) the soft starting resistor charges the DC capacitor in the three-phase back-to-back converter;

(4) After the DC capacitor reaches a steady state, close the bypass switch QF4 of the soft starting circuit;

(5) Closing the switch QF1, the main circuit of the test charges the DC bus of each link through the soft starting resistor;

(6) After the charging is stable, close the bypass switch of the test main circuit to bypass the soft starting resistor, and control each chain link to output PWM pulse;

(7) Control the output voltage of the test main circuit to be in phase with the voltage at the access point of the test main circuit, and put the test main circuit into normal operation;

(8) Controlling the three-phase back-to-back converter to output an inverter voltage whose amplitude and phase change are superimposed in the test main circuit;

(9) Simulate various faults of the power system;

(10) Verify the transient control strategy of the STATCOM controller.

Claims (13)

1. A test device for STATCOM controller, characterized in that: said test device comprises system power supply, including power supply, system impedance and contactors, for powering the test device; Transformer, used to change the voltage, so that the voltage of the grid system matches the voltage of the test device; Voltage disturbance generating device, used to construct the voltage at the access point of the test main circuit; A switch circuit is used to realize the connection and exit of the test main circuit; Control and protection systems to control and protect the operation and operation of the entire installation; and Test the main circuit, used to test the action logic of STATCOM. 2. A kind of test device for STATCOM controller according to claim 1, it is characterized in that: described system power supply, transformer, switch loop and test main circuit are connected in series successively, and described voltage disturbance generating device input side is connected with the The output ends of the system power supply are connected in parallel, and the output side is connected in series between the transformer and the switch circuit. 3. A kind of test device for STATCOM controller according to any one of claims 1-2, characterized in that: the voltage disturbance generating device includes a start switch QF2, a soft starting circuit, a three-phase rectifier transformer, a three-phase Back-to-back converters and three-phase filter circuits. 4. A test device for a STATCOM controller according to claim 3, characterized in that: the soft-start circuit comprises a soft-start resistor R4 and a bypass switch QF4 connected in parallel thereto. 5. A kind of test device for STATCOM controller according to claim 3, is characterized in that: described three-phase rectifier transformer is multi-winding transformer, and described multi-winding transformer is three-phase independent transformer or three-phase integrated transformer . 6. A kind of test device for STATCOM controller according to claim 5, it is characterized in that: the input end of each phase back-to-back converter is connected with the output end of each phase rectifier transformer, and its output end is connected with each phase filter circuit connection. 7. A kind of test device for STATCOM controller according to claim 6, it is characterized in that: described each phase filter circuit comprises inductance, resistance and capacitance, described resistance and capacitance are connected in series and occur with described voltage disturbance The output terminal of the device is connected in parallel, and the inductance is connected in series with the output terminal of the voltage disturbance generating device. 8. A kind of test device for STATCOM controller according to claim 1, is characterized in that: described switch circuit comprises arrester F, fuse FU2, potential transformer and switch QF1; Described arrester F is used for all Overvoltage protection of the test main circuit. 9. A kind of test device for STATCOM controller according to any one of claims 1-2, characterized in that: said test main circuit comprises current transformers, reactors, soft starting circuits and cascade series connected in series successively. H-type chain link; The current transformer is used to detect current; The reactor is used to suppress the high-order harmonic current generated by the H-type chain link; The DC capacitance of the H-shaped chain link plays a role of voltage support. 10. A test device for a STATCOM controller according to claim 9, characterized in that: said soft start circuit comprises a soft start resistor and a bypass switch connected in parallel therewith. 11. A test device for STATCOM controllers according to claim 1, characterized in that: the control and protection system includes a background workstation, a communication management machine, an on-site monitoring system, a controller, and a three-phase commutation chain Phase control unit and three-phase commutation chain unit controller. 12. A test device for a STATCOM controller according to claim 1, characterized in that: the test device is connected in parallel with a bypass switch at the output end of the voltage disturbance generating device or through the back-to-back transformer of each phase. The zero-voltage output of the rectifier realizes that the voltage disturbance generating device exits the test device. 13. A test method for STATCOM controller, characterized in that: said test method comprises the following steps: (1) closing the circuit breaker QZ of the system power supply; (2) closing the start switch QF2; (3) the soft starting resistor charges the DC capacitor in the three-phase back-to-back converter; (4) After the DC capacitor reaches a steady state, close the bypass switch QF4 of the soft starting circuit; (5) Closing the switch QF1, the main circuit of the test charges the DC bus of each link through the soft starting resistor; (6) After the charging is stable, close the bypass switch of the test main circuit to bypass the soft starting resistor, and control each chain link to output PWM pulse; (7) Control the output voltage of the test main circuit to be in phase with the voltage at the access point of the test main circuit, and put the test main circuit into normal operation; (8) Controlling the three-phase back-to-back converter to output an inverter voltage whose amplitude and phase change are superimposed in the test main circuit; (9) Simulate various faults of the power system; (10) Verify the transient control strategy of the STATCOM controller.

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