Test device and method for a controllable commutation valve

Abstract

The application relates to a testing device and method of a controllable commutation converter valve. The device comprises: a current source circuit for providing a conduction state current for the controllable commutation converter valve when the controllable commutation converter valve is in a conduction state; a voltage source circuit for providing a commutation voltage for the controllable commutation converter valve when the controllable commutation converter valve is in an off state; an active off circuit for providing an off test current for the controllable commutation converter valve; and a processing module for controlling the working states of the current source circuit, the voltage source circuit and the active off circuit respectively, simulating a target test working condition for the controllable commutation converter valve, and collecting electrical parameters of the controllable commutation converter valve under the target test working condition. The device of the application can simulate a single working condition or a mixed working condition for the controllable commutation converter valve, and perform a mixed operation test.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric power, in particular to a testing device and method of controllable commutation converter valve. BACKGROUND

[0002] With the development of power transmission technology, high-voltage direct current transmission technology appears, which has the advantages of high voltage level, long transmission distance and large transmission capacity.

[0003] At present, high-voltage direct current transmission adopts grid commutation converter based on thyristor devices. When the AC line fails, the commutation failure problem exists in the inverter side of the converter, which seriously affects the reliability of high-voltage direct current transmission. Therefore, with the continuous development of power semiconductor devices, active commutation converter valve appears. Compared with the grid commutation converter based on thyristor devices, it has the function of active turn-off, so that it can actively turn off and realize the controllability of commutation in the case of AC fault, greatly improving the reliability of high-voltage direct current transmission system. However, in order to ensure the reliable and stable operation of the active commutation converter valve in actual engineering application, the active commutation converter valve needs to be tested first. SUMMARY

[0004] Therefore, it is necessary to provide a testing device and method of controllable commutation converter valve which can test the performance and reliability of active commutation converter valve in view of the above technical problems.

[0005] A testing device of controllable commutation converter valve, the device comprises:

[0006] A current source circuit connected with the controllable commutation converter valve, used to provide on-state current for the controllable commutation converter valve when the controllable commutation converter valve is in the on-state;

[0007] A voltage source circuit connected with the controllable commutation converter valve, used to provide commutation voltage for the controllable commutation converter valve when the controllable commutation converter valve is in the off-state;

[0008] An active turn-off circuit connected with the controllable commutation converter valve, used to provide turn-off test current for the controllable commutation converter valve when the controllable commutation converter valve is in the on-state;

[0009] The processing module is connected with the current source circuit, the voltage source circuit, the active turn-off circuit and the controllable commutation thyristor respectively, and is configured to control working states of the current source circuit, the voltage source circuit and the active turn-off circuit respectively, simulate a target test working condition for the controllable commutation thyristor, and collect electrical parameters of the controllable commutation thyristor under the target test working condition, wherein the electrical parameters are used to determine a test result of the controllable commutation thyristor, and the target test working condition comprises at least one of an active turn-off test working condition and a commutation turn-off test working condition.

[0010] In one of the embodiments, the active turn-off circuit comprises a first DC power supply, a first energy storage unit, a first switch unit and a first discharge output unit, wherein the first DC power supply is connected with the first energy storage unit in parallel, and is configured to charge the first energy storage unit; the first energy storage unit is configured to store electrical energy; the first switch unit is arranged in series between a positive electrode of the controllable commutation thyristor and the first energy storage unit, and is configured to control a conduction or turn-off of a path between the positive electrode of the controllable commutation thyristor and the first energy storage unit; and the first discharge output unit is arranged in series between the positive electrode of the controllable commutation thyristor and the first energy storage unit, so that the first energy storage unit provides a stable turn-off test current for the controllable commutation thyristor.

[0011] In one of the embodiments, the first energy storage unit comprises a first capacitor, the first switch unit comprises a first controllable valve, the first discharge output unit comprises a first inductor, a second inductor and a freewheeling diode, the first capacitor is connected with the first DC power supply in parallel, a positive electrode of the first controllable valve is connected with a first end of the first capacitor, a negative electrode of the first controllable valve is connected with a first end of the first inductor, a second end of the first inductor is connected with the positive electrode of the controllable commutation thyristor, a second end of the first capacitor is connected with a negative electrode of the controllable commutation thyristor, the second inductor is arranged in series between the positive electrode of the first controllable valve and the first end of the first capacitor, a positive electrode of the freewheeling diode is connected with the positive electrode of the first controllable valve, and a negative electrode of the freewheeling diode is connected with the first end of the first capacitor, wherein the first controllable valve is configured to be turned on during testing of the active turn-off performance of the controllable commutation thyristor, so that the first capacitor discharges to the controllable commutation thyristor through the first inductor to provide the turn-off test current; and the controllable commutation thyristor is configured to actively turn off when an amplitude of the turn-off test current reaches a first set value.

[0012] In one of the embodiments, the active turn-off test working condition comprises a first conduction phase, an active turn-off phase, and a first commutation phase; the processing module controls the current source circuit to provide a conduction current for the controllable commutated thyristor, and controls the active turn-off circuit to provide a turn-off test current for the controllable commutated thyristor, so as to simulate the first conduction phase; the controllable commutated thyristor is actively turned off, and the active turn-off circuit provides a support voltage for the controllable commutated thyristor, so as to simulate the active turn-off phase; and the processing module controls the voltage source circuit to provide a commutation voltage for the controllable commutated thyristor, so as to simulate the first commutation phase.

[0013] In one of the embodiments, the voltage source circuit comprises a second DC power supply, a second switch unit, a voltage polarity reversal unit, a second energy storage unit, a commutation unit, a second discharge output unit, and a third energy storage unit; a positive electrode of the second DC power supply is connected with a first end of the second switch unit; a second end of the second switch unit is connected with a first end of the voltage polarity reversal unit; a negative electrode of the second DC power supply is connected with a second end of the voltage polarity reversal unit and a negative electrode of the controllable commutated thyristor respectively; the second energy storage unit is connected with the voltage polarity reversal unit in parallel; the commutation unit is connected in series between the second energy storage unit and a positive electrode of the controllable commutated thyristor; the second discharge output unit is connected in series between the second energy storage unit and the positive electrode of the controllable commutated thyristor; and the third energy storage unit is connected with the controllable commutated thyristor in parallel; wherein the voltage polarity reversal unit is configured to adjust the polarity of the voltage on the second energy storage unit; and the commutation unit is configured to adjust the polarity of the voltage applied to the controllable commutated thyristor.

[0014] In one of the embodiments, the second switch unit comprises a second controllable valve; the second energy storage unit comprises a second capacitor; the third energy storage unit comprises a third capacitor; and the second discharge output unit comprises a third inductor; a positive electrode of the second DC power supply is connected with a positive electrode of the second controllable valve; a negative electrode of the second controllable valve is connected with a first end of the voltage polarity reversal unit; a negative electrode of the second DC power supply is connected with a second end of the voltage polarity reversal unit and a negative electrode of the controllable commutated thyristor respectively; the second capacitor is connected with the voltage polarity reversal unit in parallel; a first end of the commutation unit is connected with a first end of the second capacitor; a second end of the commutation unit is connected with a first end of the third inductor; a second end of the third inductor is connected with a positive electrode of the controllable commutated thyristor; and the third capacitor is connected with the controllable commutated thyristor in parallel.

[0015] In one of the embodiments, the voltage polarity reversing unit comprises: a fourth inductor, a third controllable valve, and a fourth controllable valve, a first end of the fourth inductor is connected with a negative electrode of the second controllable valve, a second end of the fourth inductor is connected with a first end of the commutation unit and a first end of the second capacitor respectively, a second end of the second capacitor is connected with a negative electrode of the second DC power supply, a positive electrode of the third controllable valve is connected with a negative electrode of the fourth controllable valve and a negative electrode of the second DC power supply respectively, and a negative electrode of the third controllable valve is connected with a positive electrode of the fourth controllable valve and a first end of the fourth inductor respectively; wherein, the third controllable valve and the fourth controllable valve are used for time-sharing conduction to adjust the polarity of the voltage on the second capacitor.

[0016] In one of the embodiments, the commutation unit comprises: a fifth controllable valve and a sixth controllable valve, a positive electrode of the fifth controllable valve is connected with a negative electrode of the sixth controllable valve and a first end of the second capacitor respectively, and a negative electrode of the fifth controllable valve is connected with a positive electrode of the sixth controllable valve and a first end of the third inductor respectively; wherein, the fifth controllable valve and the sixth controllable valve are used for time-sharing conduction to adjust the polarity of the voltage applied to the controllable commutation thyristor.

[0017] In one of the embodiments, the current source circuit comprises: a power supply and a rectification-inversion counter-circuit, the rectification-inversion counter-circuit is connected with the power supply and the controllable commutation thyristor respectively, and the rectification-inversion counter-circuit is used for equivalent current stress of the controllable commutation thyristor under power supply of the power supply.

[0018] In one of the embodiments, the device further comprises an isolation valve, the isolation valve is connected with the rectification-inversion counter-circuit and the controllable commutation thyristor respectively, and the isolation valve is used for isolating the rectification-inversion counter-circuit and the controllable commutation thyristor.

[0019] In one of the embodiments, the isolation valve comprises an inverse resistance type integrated gate commutation thyristor.

[0020] In one of the embodiments, the test device of the controllable commutation thyristor further comprises:

[0021] An impulse voltage circuit is connected with the controllable commutation thyristor, and is used for providing impulse voltage for the controllable commutation thyristor.

[0022] In one of the embodiments, the impulse voltage circuit comprises: an impulse generator and a switch, a ball gap is arranged between a first end of the impulse generator and a first end of the switch, a second end of the impulse generator is connected with a negative electrode of the controllable commutation thyristor, and a second end of the switch is connected with a positive electrode of the controllable commutation thyristor.

[0023] In one of the embodiments, the test device of the controllable commutation thyristor further comprises a fault current circuit connected with the controllable commutation thyristor, for providing a fault current for the controllable commutation thyristor.

[0024] In one of the embodiments, the fault current circuit comprises a fault power supply, a fourth capacitor, a fifth inductor, and a seventh controllable valve, the fault power supply is connected with the fourth capacitor in parallel, the first end of the fifth inductor is connected with the first end of the fourth capacitor, the second end of the fifth inductor is connected with the positive electrode of the seventh controllable valve, the negative electrode of the seventh controllable valve is connected with the positive electrode of the controllable commutation thyristor, and the second end of the fourth capacitor is connected with the negative electrode of the controllable commutation thyristor.

[0025] A test method of a controllable commutation thyristor, the method is applied to the test device of the controllable commutation thyristor, and the method comprises:

[0026] Controlling the working states of the current source circuit and the voltage source circuit respectively, so as to simulate a commutation-related turn-off test working condition for the controllable commutation thyristor;

[0027] Controlling the working states of the current source circuit, the voltage source circuit, and the active turn-off circuit respectively, and controlling the controllable commutation thyristor to actively turn off when the amplitude of the turn-off test current reaches a first set value, so as to simulate an active turn-off test working condition for the controllable commutation thyristor;

[0028] Obtaining an electrical parameter of the controllable commutation thyristor under a target test working condition, wherein the target test working condition comprises at least one of the active turn-off test working condition and the commutation-related turn-off test working condition;

[0029] Determining a test result of the controllable commutation thyristor based on the electrical parameter.

[0030] In one of the embodiments, the active turn-off test working condition comprises a first conduction phase, an active turn-off phase, and a first commutation phase, and the controlling the working states of the current source circuit, the voltage source circuit, and the active turn-off circuit respectively, and controlling the controllable commutation thyristor to actively turn off when the amplitude of the turn-off test current reaches a first set value, so as to simulate an active turn-off test working condition for the controllable commutation thyristor, comprises:

[0031] Controlling the current source circuit to provide a conduction current for the controllable commutation thyristor, controlling the active turn-off circuit to provide a turn-off test current for the controllable commutation thyristor, and controlling the controllable commutation thyristor to actively turn off when the amplitude of the turn-off test current reaches a first set value, so as to simulate the first conduction phase;

[0032] The controllable commutation converter valve is actively turned off, the active turn-off circuit provides a support voltage for the controllable commutation converter valve to simulate the active turn-off stage.

[0033] The voltage source circuit controls the controllable commutation converter valve to provide a commutation voltage to simulate the first commutation stage.

[0034] The test device and method of the controllable commutation converter valve. By setting the current source circuit, the controllable commutation converter valve can be provided with a on-state current, thereby facilitating the simulation of the current received when the controllable commutation converter valve is normally turned on, thereby simulating the working condition of the controllable commutation converter valve when it is normally turned on. By setting the voltage source circuit, the controllable commutation converter valve can be provided with a commutation voltage, and the polarity of the commutation voltage can be reversed, thereby simulating the working condition of the controllable commutation converter valve during normal turn-off. Thus, by cooperating the current source circuit and the voltage source circuit, the controllable commutation converter valve is simulated to be turned on and turned off under normal working conditions. By setting the active turn-off circuit, the controllable commutation converter valve can be provided with a turn-off test current, which is the test current for the active turn-off of the controllable commutation converter valve, and can simulate the test conditions required for the active turn-off test working condition of the controllable commutation converter valve when it is normally working, thereby facilitating the test of the active turn-off performance of the controllable commutation converter valve. By setting the processing module, the working states of the current source circuit, the voltage source circuit and the active turn-off circuit are controlled respectively, and the target test working condition of the controllable commutation converter valve is simulated, that is, the controllable commutation converter valve can be simulated by cooperating the current source circuit and the voltage source circuit to simulate the commutation turn-off test working condition, and the electrical parameters of the controllable commutation converter valve under the commutation turn-off test working condition can be collected, and the controllable commutation converter valve can be simulated by cooperating the current source circuit, the voltage source circuit and the active turn-off circuit to simulate the active turn-off test working condition. In summary, the device of the present application can simulate single working condition or mixed working condition for the controllable commutation converter valve, perform mixed operation test, and collect electrical parameters of the controllable commutation converter valve under the active turn-off test working condition. The test results of the controllable commutation converter valve can be determined by the collected electrical parameters, and the performance and reliability of the controllable commutation converter valve can be judged, thereby realizing the test of the controllable commutation converter valve. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creating laborious work.

[0036] Figure 1Fig. 1 is a structural schematic diagram of a test device for a controllable commutation thyristor valve in an embodiment;

[0037] Figure 2 Fig. 2 is a structural schematic diagram of a test device for a controllable commutation thyristor valve in an embodiment;

[0038] Figure 3 Fig. 3 is a structural schematic diagram of a test device for a controllable commutation thyristor valve in an embodiment;

[0039] Figure 4 Fig. 4 is a structural schematic diagram of a test device for a controllable commutation thyristor valve in an embodiment;

[0040] Figure 5 Fig. 5 is a current-voltage waveform diagram of a test device in an active turn-off test mode in an embodiment;

[0041] Figure 6 Fig. 6 is a current-voltage waveform diagram of a test device in a commutation-related turn-off test mode in an embodiment;

[0042] Figure 7 Fig. 7 is a structural schematic diagram of a test device for a controllable commutation thyristor valve in an embodiment;

[0043] Figure 8 Fig. 8 is a structural schematic diagram of a test device for a controllable commutation thyristor valve in an embodiment;

[0044] Figure 9 Fig. 9 is a flowchart of a test method for a controllable commutation thyristor valve in an embodiment;

[0045] Figure 10 Fig. 10 is a flowchart of an active turn-off test method for a controllable commutation thyristor valve in an embodiment.

[0046] BRIEF DESCRIPTION OF THE DRAWINGS

[0047] 10 - current source circuit, 20 - voltage source circuit, 30 - active turn-off circuit, 40 - processing module, 50 - controllable commutation thyristor valve, 31 - first DC power supply, 32 - first energy storage unit, 33 - first switching unit, 34 - first discharge output unit, 21 - second DC power supply, 22 - second switching unit, 23 - voltage polarity inversion unit, 24 - second energy storage unit, 25 - commutation unit, 26 - second discharge output unit, 27 - third energy storage unit, 11 - power supply, 12 - rectification and inversion counter-coupling circuit, 121 - first three-phase full-bridge rectification circuit, 122 - second three-phase full-bridge rectification circuit, 60 - impulse voltage circuit, 61 - impulse generator, 70 - fault current circuit, 71 - fault power supply. DETAILED DESCRIPTION

[0048] For the purpose of clarity, the present application will be described in greater detail below with reference to the accompanying drawings. The embodiments of the present application are shown in the drawings. However, the present application can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and fully convey the scope of the application to those skilled in the art.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0050] It should be understood that the terms "first", "second", etc. used herein can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element.

[0051] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through a central element. In addition, "connected" in the following embodiments should be understood as "electrically connected", "communicatively connected" and the like if there is transmission of electrical signals or data between the connected objects.

[0052] As used herein, the singular forms "a", "an" and "the" can include plural forms unless the context clearly indicates otherwise. It should also be understood that the terms "comprise / comprising" or "have / having" specify the presence of stated features, integers, steps, operations, components, parts or combinations thereof, but do not exclude the presence or addition of one or more other features, integers, steps, operations, components, parts or combinations thereof.

[0053] In one embodiment, as shown in Figure 1 A test device for a controllable commutation thyristor is provided, which comprises a current source circuit 10, a voltage source circuit 20, an active turn-off circuit 30, a processing module 40, wherein:

[0054] The current source circuit 10 is connected to the controllable commutation thyristor 50, and is used to provide a on-state current for the controllable commutation thyristor 50 when the controllable commutation thyristor 50 is in a on-state.

[0055] The current source circuit 10 can provide a steady-state direct current for the controllable commutation thyristor 50, so as to simulate the current flowing through the controllable commutation thyristor 50 when it is in a normal on-state, simulate the actual working condition, and facilitate the test of the controllable commutation thyristor 50.

[0056] Exemplarily, the controllable commutation thyristor 50 is turned on for at least one third of the time (6.67 ms) in one power frequency cycle (for example, 20 ms). The on-state current provided by the current source circuit 10 can be 1000 A~7000 A.

[0057] The controllable commutation thyristor 50 can include at least one reverse blocking integrated gate commutated thyristor (IGCT) and can also include a plurality of reverse blocking IGCTs in series. Commutation failure is one of the common faults of the inverter side of a DC power transmission system, which will cause the DC voltage of the DC power transmission system to decrease, the transmitted power to decrease, the current to increase, the equipment of the DC converter station to be damaged, and the overvoltage of the AC system of the inverter side and other adverse consequences. In a multi-infeed DC system, a single AC fault can cause commutation failure of multiple DCs in a large range, resulting in a power impact of tens of megawatts, which seriously threatens the safe operation of the power grid. The controllable commutation thyristor 50 can realize controllable active turn-off, has the characteristics of large capacity and low loss of a thyristor, and also has the ability of active turn-off, so that it can actively turn off under AC fault and realize controllable commutation, thereby essentially solving the problem of commutation failure.

[0058] The voltage source circuit 20 is connected with the controllable commutation thyristor 50 and is used to provide a commutation voltage for the controllable commutation thyristor 50 when the controllable commutation thyristor 50 is in the turn-off state.

[0059] The voltage source circuit 20 can provide a transient recovery voltage, i.e., a commutation voltage, when the controllable commutation thyristor 50 is turned off, so as to simulate the voltage condition that the controllable commutation thyristor 50 bears in actual use. The polarity of the commutation voltage provided by the voltage source circuit 20 can be actively reversed, so as to simulate various actual working conditions for the controllable commutation thyristor 50 according to actual needs.

[0060] The active turn-off circuit 30 is connected with the controllable commutation thyristor 50 and is used to provide a turn-off test current for the controllable commutation thyristor 50 when the controllable commutation thyristor 50 is in the on state.

[0061] When the controllable commutation thyristor 50 is in the turn-off state, the active turn-off circuit 30 can continue to provide a certain sustained current for the controllable commutation thyristor 50, the current charges the parasitic capacitor of the controllable commutation thyristor 50, and the parasitic capacitor provides a support voltage for the controllable commutation thyristor 50.

[0062] The turn-off test current is a large current, and the active turn-off circuit 30 needs to be powered by a high-voltage capacitor to output a sinusoidal current. The amplitude of the turn-off test current is generally 1 kA~10 kA, and the pulse width is about 1 ms.

[0063] The processing module 40 is connected with the current source circuit 10, the voltage source circuit 20, the active blocking circuit 30 and the controllable commutation thyristor 50 respectively, and is used for controlling the working states of the current source circuit 10, the voltage source circuit 20 and the active blocking circuit 30 respectively, simulating a target test working condition for the controllable commutation thyristor 50, and collecting electrical parameters of the controllable commutation thyristor 50 under the target test working condition.

[0064] The electrical parameters are used for determining a test result of the controllable commutation thyristor 50, and the target test working condition includes at least one of an active blocking test working condition and a commutation blocking test working condition.

[0065] The processing module 40 can control the working states of the current source circuit 10 and the voltage source circuit 20, thereby simulating the commutation blocking test working condition for the controllable commutation thyristor 50, that is, the current and voltage stress borne by the controllable commutation thyristor 50 in the whole process of normal commutation blocking, and then collecting the electrical parameters (such as voltage, current, breaking timing and the like) of the controllable commutation thyristor 50 in the whole process, to see whether the electrical parameters match or are consistent with preset electrical parameters in theory, thereby verifying the reliability and performance of the controllable commutation thyristor 50.

[0066] The processing module 40 can control the working states of the current source circuit 10, the voltage source circuit 20 and the active blocking circuit 30, thereby simulating the active blocking test working condition for the controllable commutation thyristor 50, that is, the current and voltage stress borne by the controllable commutation thyristor 50 in the whole process of normal commutation blocking combined with the process of active blocking, and then collecting the electrical parameters (such as voltage, current, breaking timing and the like) of the controllable commutation thyristor 50 in the whole process, to see whether the electrical parameters match or are consistent with preset electrical parameters in theory, thereby verifying the reliability and performance of the controllable commutation thyristor 50. Through the control of the processing module 40, the controllable commutation thyristor 50 can be simulated in a single working condition or a mixed working condition for mixed running test.

[0067] In the embodiment, by setting the current source circuit 10, the on-state current can be provided for the controllable commutation thyristor 50, so that the current received when the controllable commutation thyristor 50 is normally turned on can be simulated, and the working condition when the controllable commutation thyristor 50 is normally turned on can be simulated. By setting the voltage source circuit 20, the commutation voltage can be provided for the controllable commutation thyristor 50, and the polarity of the commutation voltage can be reversed, so that the working condition in the normal turn-off process of the controllable commutation thyristor 50 can be simulated. Therefore, by cooperating the current source circuit 10 and the voltage source circuit 20, the working conditions of turn-on and turn-off in the normal working process of the controllable commutation thyristor 50 can be simulated. By setting the active turn-off circuit 30, the turn-off test current can be provided for the controllable commutation thyristor 50, and the turn-off test current can be used as the test current for the active turn-off of the controllable commutation thyristor 50, so that the test condition required for the active turn-off test working condition of the controllable commutation thyristor 50 can be simulated when the controllable commutation thyristor 50 is normally working, and the active turn-off performance of the controllable commutation thyristor 50 can be tested. By setting the processing module 40, the working states of the current source circuit 10, the voltage source circuit 20 and the active turn-off circuit 30 can be controlled respectively, so that the target test working condition of the controllable commutation thyristor 50 can be simulated. That is, the working condition of the commutation turn-off test of the controllable commutation thyristor 50 can be simulated by cooperating the current source circuit 10 and the voltage source circuit 20, and the electrical parameters of the controllable commutation thyristor 50 under the working condition of the commutation turn-off test can be collected. In addition, the active turn-off test working condition of the controllable commutation thyristor 50 can be simulated by cooperating the current source circuit 10, the voltage source circuit 20 and the active turn-off circuit 30, and the electrical parameters of the controllable commutation thyristor 50 under the active turn-off test working condition can be collected. The test result of the controllable commutation thyristor 50 can be determined by the collected electrical parameters, and the performance and reliability of the controllable commutation thyristor 50 can be judged, so that the test of the controllable commutation thyristor 50 is realized.

[0068] In one embodiment, as shown in FIG. 1, the active turn-off test circuit comprises a first DC power supply 31, a first energy storage unit 32, a first switch unit 33 and a first discharge output unit 34. Figure 2 The first DC power supply 31 is connected in parallel with the first energy storage unit 32, and is used to charge the first energy storage unit 32.

[0069] The first energy storage unit 32 is used to store electrical energy.

[0070] The first switch unit 33 is connected in series between the positive electrode of the controllable commutation thyristor 50 and the first energy storage unit 32, and is used to control the conduction or turn-off of the path between the positive electrode of the controllable commutation thyristor 50 and the first energy storage unit 32.

[0071]

[0072] ​The first discharging output unit 34 is arranged in series between the positive electrode of the controllable commutation thyristor 50 and the first energy storage unit 32, so that the first energy storage unit 32 provides a stable turn-off test current for the controllable commutation thyristor 50.

[0073] wherein, Figure 2 The processing module 40 is not shown in the figure, and it can be understood that the working states of the power supplies and the conducting states of the valve devices in the present application can be controlled by the processing module 40, and the same understanding applies to all embodiments of the present application.

[0074] In the embodiment, by arranging the first DC power supply 31, the first energy storage unit 32, the first switch unit 33, and the first discharging output unit 34, a specific structure of the active turn-off test circuit is provided, which can provide a turn-off test current for the controllable commutation thyristor 50.

[0075] In one embodiment, please continue to refer to Figure 2 The first energy storage unit 32 includes a first capacitor C1, the first switch unit 33 includes a first controllable valve V1, the first discharging output unit 34 includes a first inductor L1, a second inductor L2, and a freewheeling diode D1, the first capacitor C1 is connected in parallel with the first DC power supply 31, the positive electrode of the first controllable valve V1 is connected with the first end of the first capacitor C1, the negative electrode of the first controllable valve V1 is connected with the first end of the first inductor L1, the second end of the first inductor L1 is connected with the positive electrode of the controllable commutation thyristor 50, the second end of the first capacitor C1 is connected with the negative electrode of the controllable commutation thyristor 50, the second inductor L2 is arranged in series between the positive electrode of the first controllable valve V1 and the first end of the first capacitor C1, the positive electrode of the freewheeling diode D1 is connected with the positive electrode of the first controllable valve V1, and the negative electrode of the freewheeling diode D1 is connected with the first end of the first capacitor C1.

[0076] The first controllable valve V1 is used to be turned on during the process of testing the active turn-off performance of the controllable commutation thyristor 50, so that the first capacitor C1 discharges to the controllable commutation thyristor 50 through the first inductor L1 to provide a turn-off test current.

[0077] The first inductor L1 is a controllable commutation inductance of the controllable commutation thyristor valve 50, and is a variable inductance. The inductance value of the first inductor L1 can be adjusted according to the number of series-connected reverse blocking IGCT devices included in the controllable commutation thyristor valve 50, so as to simulate a more real commutation inductance value of the controllable commutation thyristor valve 50 under actual operation conditions. The active turn-off test circuit is used to simulate the active turn-off condition of the controllable commutation thyristor valve 50 in operation, and needs to be equivalent to the actual condition of the controllable commutation thyristor valve 50 in terms of current, voltage waveform and turn-off energy. Therefore, for the controllable commutation thyristor valve 50 with different series numbers, in order to ensure the equivalence of the turn-off energy, the first inductor L1 needs to be adjustable, and can be adjusted based on the series number of the series-connected reverse blocking IGCT devices included in the controllable commutation thyristor valve 50.

[0078] The second inductor L2 is a discharge inductance, and the inductance value is fixed. This is because the pulse width is fixed (the resonant circuit composed of the second inductor L2 and the first capacitor C1, and the values of L2 and C1 determine the resonant period), and the safety of the test is also considered (it is safer when the inductance is large and the capacitance is small, so that the short-circuit current of the controllable commutation thyristor valve 50 in failure can be small). Therefore, the two inductors L1 and L2 are designed in series, the loop inductance is increased, and the freewheeling diode D1 is connected in anti-parallel with the second inductor L2. When the controllable commutation thyristor valve 50 actively turns off, the current of the second inductor L2 is freewheeling. The controllable commutation thyristor valve 50 only needs to consume the current of the first inductor L1, and the equivalence of the condition under the turn-off condition is high, and the simulated condition is more real.

[0079] The controllable commutation thyristor valve 50 is used to actively turn off when the amplitude of the test current reaches the first set value. The first set value can be a value set in advance according to the actual test requirement.

[0080] In the embodiment, the safety in the active turn-off test process is improved by designing the first inductor L1 and the second inductor L2, and the first inductor L1 can be adjusted according to the series number of the series-connected reverse blocking IGCT devices included in the controllable commutation thyristor valve 50, so as to improve the reality of the active turn-off test condition.

[0081] In one embodiment, as Figure 3As shown, the voltage source circuit 20 comprises: a second DC power supply 21, a second switch unit 22, a voltage polarity reversal unit 23, a second energy storage unit 24, a commutation unit 25, a second discharge output unit 26, and a third energy storage unit 27. The positive pole of the second DC power supply 21 is connected with the first end of the second switch unit 22. The second end of the second switch unit 22 is connected with the first end of the voltage polarity reversal unit 23. The negative pole of the second DC power supply 21 is connected with the second end of the voltage polarity reversal unit 23 and the negative pole of the controllable commutation thyristor 50 respectively. The second energy storage unit 24 is connected with the voltage polarity reversal unit 23 in parallel. The commutation unit 25 is connected in series between the second energy storage unit 24 and the positive pole of the controllable commutation thyristor 50. The second discharge output unit 26 is connected in series between the second energy storage unit 24 and the positive pole of the controllable commutation thyristor 50. The third energy storage unit 27 is connected with the controllable commutation thyristor 50 in parallel.

[0082] The voltage polarity reversal unit 23 is configured to adjust the polarity of the voltage on the second energy storage unit 24. The commutation unit 25 is configured to adjust the polarity of the voltage applied to the controllable commutation thyristor 50.

[0083] In the embodiment, a specific structure of the voltage source circuit 20 is provided, which can provide the controllable commutation thyristor 50 with commutation voltages of different polarities, so as to simulate the working condition of the controllable commutation thyristor 50 in the normal turn-off process. By designing the voltage polarity reversal unit 23, the polarity of the voltage on the second energy storage unit 24 can be actively adjusted, so as to make the polarity of the voltage on the second energy storage unit 24 consistent with that in the actual working condition, and improve the authenticity of the simulated working condition.

[0084] In one embodiment, please continue to refer to Figure 3 The second switch unit 22 comprises a second controllable valve V2. The second energy storage unit 24 comprises a second capacitor C2. The third energy storage unit 27 comprises a third capacitor C3. The second discharge output unit 26 comprises a third inductor L3. The positive pole of the second DC power supply 21 is connected with the positive pole of the second controllable valve V2. The negative pole of the second controllable valve V2 is connected with the first end of the voltage polarity reversal unit 23. The negative pole of the second DC power supply 21 is connected with the second end of the voltage polarity reversal unit 23 and the negative pole of the controllable commutation thyristor 50 respectively. The second capacitor C2 is connected with the voltage polarity reversal unit 23 in parallel. The first end of the commutation unit 25 is connected with the first end of the second capacitor C2. The second end of the commutation unit 25 is connected with the first end of the third inductor L3. The second end of the third inductor L3 is connected with the positive pole of the controllable commutation thyristor 50. The third capacitor C3 is connected with the controllable commutation thyristor 50 in parallel.

[0085] The third capacitor C3 is configured to simulate the parasitic capacitance caused by the devices around the controllable commutation thyristor 50 when the controllable commutation thyristor 50 is installed in the actual power system, so as to make the working condition of the controllable commutation thyristor 50 more authentic.

[0086] In the embodiment, the second switch unit 22 comprises a second controllable valve V2, the second energy storage unit 24 comprises a second capacitor C2, the third energy storage unit 27 comprises a third capacitor C3, and the second discharge output unit 26 comprises a third inductor L3, thereby providing a specific circuit structure and realizing the corresponding required functions.

[0087] In one embodiment, please continue to refer to Figure 3 , the voltage polarity reversing unit 23 comprises a fourth inductor L4, a third controllable valve V3, and a fourth controllable valve V4. The first end of the fourth inductor L4 is connected with the negative electrode of the second controllable valve V2. The second end of the fourth inductor L4 is connected with the first end of the commutation unit 25 and the first end of the second capacitor C2 respectively. The second end of the second capacitor C2 is connected with the negative electrode of the second DC power supply 21. The positive electrode of the third controllable valve V3 is connected with the negative electrode of the fourth controllable valve V4 and the negative electrode of the second DC power supply 21 respectively. The negative electrode of the third controllable valve V3 is connected with the positive electrode of the fourth controllable valve V4 and the first end of the fourth inductor L4 respectively.

[0088] The third controllable valve V3 and the fourth controllable valve V4 are used for time-sharing conduction to adjust the polarity of the voltage on the second capacitor C2. When the third controllable valve V3 is turned on, the second capacitor C2 discharges to the fourth inductor L4 through the third controllable valve V3. When the second capacitor C2 discharges, the positive current passes through the third controllable valve V3, and the negative current is cut off by the third controllable valve V3. Then, the electric energy generated by the passing current is stored on the fourth inductor L4. Then, the fourth inductor L4 charges the second capacitor C2 again. The second capacitor C2 and the fourth inductor L4 constitute a resonant circuit, and the voltage polarity on the second capacitor C2 is positive. When the fourth controllable valve V4 is turned on, the second capacitor C2 discharges to the fourth inductor L4 through the fourth controllable valve V4. When the second capacitor C2 discharges, the negative current passes through the fourth controllable valve V4, and the positive current is cut off by the fourth controllable valve V4. Then, the electric energy generated by the passing current is stored on the fourth inductor L4. Then, the fourth inductor L4 charges the second capacitor C2 again. The second capacitor C2 and the fourth inductor L4 constitute a resonant circuit, and the voltage polarity on the second capacitor C2 is negative.

[0089] In the embodiment, by setting the voltage polarity reversing unit 23, the active reversal adjustment of the voltage polarity on the second capacitor C2 can be realized. The voltage polarity of the second capacitor C2 can be actively adjusted according to the requirements of the actual working condition to be simulated, and a more realistic working condition can be simulated.

[0090] In one embodiment, please continue to refer to Figure 3The commutation unit 25 includes a fifth controllable valve V5 and a sixth controllable valve V6. The positive terminal of the fifth controllable valve V5 is connected to the negative terminal of the sixth controllable valve V6 and the first terminal of the second capacitor C2, respectively. The negative terminal of the fifth controllable valve V5 is connected to the positive terminal of the sixth controllable valve V6 and the first terminal of the third inductor L3, respectively.

[0091] The fifth controllable valve V5 and the sixth controllable valve V6 are used for time-sharing conduction to adjust the polarity of the voltage applied to the controllable commutator valve 50. When the fifth controllable valve V5 is on, the second capacitor C2 discharges through the fifth controllable valve V5 to the third inductor L3. When the second capacitor C2 discharges, a positive current flows through the fifth controllable valve V5, while a negative current is cut off by the fifth controllable valve V5. The electrical energy generated by the current is stored in the third inductor L3, and then the third inductor L3 discharges to the controllable commutator valve 50, resulting in a positive voltage polarity on the controllable commutator valve 50. When the sixth controllable valve V6 is on, the second capacitor C2 discharges through the sixth controllable valve V6 to the controllable commutator valve 50. When the second capacitor C2 discharges, a negative current flows through the sixth controllable valve V6, while a positive current is cut off by the sixth controllable valve V6, resulting in a negative voltage polarity on the controllable commutator valve 50.

[0092] In this embodiment, by setting the commutation unit 25, the voltage polarity of the controllable commutation valve 50 can be adjusted. According to the actual working conditions to be simulated, the voltage polarity applied to the controllable commutation valve 50 can be actively adjusted to simulate a more realistic working condition.

[0093] In one embodiment, such as Figure 4 As shown, the current source circuit 10 includes a power supply 11 and a rectifier-inverter circuit 12. The rectifier-inverter circuit 12 is connected to both the power supply 11 and the controllable commutator valve 50. For example, the power supply 11 is a generator. The rectifier-inverter circuit 12, powered by the power supply 11, is used to output a current waveform according to the power frequency cycle, equivalent to the current stress of the controllable commutator valve 50, for testing the controllable commutator valve 50.

[0094] For example, the rectifier-inverter coupled circuit 12 includes a first three-phase full-bridge rectifier circuit 121, a second three-phase full-bridge rectifier circuit 122, and a smoothing reactor L0. For example, the first three-phase full-bridge rectifier circuit 121 includes six switching valves (K7~K12) forming a three-phase full-bridge arm; the second three-phase full-bridge rectifier circuit 122 includes six switching valves (K1~K6) forming another three-phase full-bridge arm. In this system, the positive terminals of switching valves K1, K3, and K5 are connected to the first terminal of the smoothing reactor L0. The negative terminals of switching valves K1, K3, and K5, and the positive terminals of switching valves K2, K4, and K6, are connected to the first terminal of the power supply 11 via a converter transformer. The negative terminals of switching valves K2, K4, and K6, and the positive terminals of switching valves K7, K9, and K11, are grounded. The negative terminals of switching valves K7, K9, and K11, and the positive terminals of switching valves K8, K10, and K12, are connected to the second terminal of the power supply 11 via a converter transformer. The negative terminals of switching valves K8, K10, and K12 are connected to the second terminal of the smoothing reactor L0. The smoothing reactor L0 is used to stabilize the DC current flowing through it.

[0095] The controllable commutation valve 50 can be connected in parallel with any lower bridge arm of either phase in the first three-phase full-bridge rectifier circuit 121 or the second three-phase full-bridge rectifier circuit 122. For example, Figure 4 In this circuit, the controllable commutator valve 50 is connected in parallel with the lower arm of the third phase of the second three-phase full-bridge rectifier circuit 122. That is, the positive terminal of the controllable commutator valve 50 is connected to the negative terminal of switching valve K5 and the positive terminal of switching valve K6, respectively, while the negative terminal of the controllable commutator valve 50 is grounded. The controllable commutator valve 50 is connected in parallel with the switching valve K6. For ease of description, the arm to which the controllable commutator valve 50 is connected is referred to as the test arm.

[0096] It should be noted that the current source circuit 10 can operate independently, meaning it can function normally without the controllable commutation valve 50 connected. During testing with the controllable commutation valve 50 connected, the test bridge arm (e.g., Figure 4 The switching valves K5 and K6 in the circuit trigger the controllable commutator valve 50 on the test branch. The rectifier-inverter circuit 12 can simulate the current stress of the controllable commutator valve 50 under the power supply of the power supply 11. That is, it simulates the controllable commutator valve 50 under normal conduction state and outputs the current waveform according to the power frequency cycle to test the controllable commutator valve 50.

[0097] In one embodiment, please see [link to previous article]. Figure 4 The test device for the controllable commutation valve also includes an isolation valve Vs. The isolation valve Vs is connected to the rectifier-inverter circuit 12 and the controllable commutation valve 50 respectively. The isolation valve Vs is used to isolate the rectifier-inverter circuit 12 and the controllable commutation valve 50.

[0098] For example, in Figure 4 , the positive pole of the isolation valve Vs is connected with the negative pole of the switching valve K5 and the positive pole of the switching valve K6 in the rectifier-inverter pair circuit 12 respectively, and the negative pole of the isolation valve Vs is connected with the positive pole of the controllable commutation valve 50. In this way, by setting the isolation valve Vs, not only the conduction or shutdown of the path between the rectifier-inverter pair circuit 12 and the controllable commutation valve 50 can be controlled, but also the high voltage in the testing device can be isolated from the low voltage, thereby improving the controllability, stability and safety of the testing device.

[0099] The isolation valve Vs includes an inverse blocking type integrated gate commutated thyristor (IGCT) device.

[0100] The isolation valve Vs can include a plurality of inverse blocking type IGCT devices connected in series, so that the reverse recovery time of the isolation valve Vs can be controlled within 50μs, and the circuit can achieve a minimum 1-2° shutdown angle. More accurate control of the on-state current flowing through the controllable commutation valve 50 can be achieved.

[0101] When the isolation valve Vs is turned on, the test bridge arm of the rectifier-inverter pair circuit 12 is turned on, and the rectifier-inverter pair circuit 12 provides an on-state current (for example, 1000A-7000A) to the controllable commutation valve 50, so that the controllable commutation valve 50 is turned on, which can be turned on according to a preset conduction rule (for example, in one power frequency cycle (20ms), at least one-third of the time (6.67ms) is turned on), thereby simulating the normal conduction of the controllable commutation valve 50. When the isolation valve Vs is turned off, the current source circuit 10 and the voltage source circuit 20 can be isolated, and the current source circuit 10 and the active shutdown circuit 30 can be isolated, thereby preventing the voltage on the voltage source circuit 20 and the active shutdown circuit 30 from damaging the current source circuit 10.

[0102] In the embodiment, by setting the isolation valve Vs, the on-state current on the controllable commutation valve 50 can be accurately controlled, and the current source circuit 10 can be protected, thereby improving the accuracy and safety of the test.

[0103] In one embodiment, please continue to refer to Figure 4 , in combination with Figure 4 to describe the active shutdown test working condition of the present application.

[0104] The active shutdown test working condition includes a first conduction phase, an active shutdown phase, and a first commutation phase.

[0105] The processing module 40 controls the current source circuit 10 to provide a conduction current for the controllable commutation thyristor 50, and controls the active turn-off circuit 30 to provide a turn-off test current for the controllable commutation thyristor 50 to simulate the first conduction stage.

[0106] The controllable commutation thyristor 50 is actively turned off, and the active turn-off circuit 30 provides a support voltage for the controllable commutation thyristor 50 to simulate the active turn-off stage.

[0107] The processing module 40 controls the voltage source circuit 20 to provide a commutation voltage for the controllable commutation thyristor 50 to simulate the first commutation stage.

[0108] Specifically, the whole process of the active turn-off test working condition is described, and the waveform diagram shown in FIG. 4 can be referred to. Figure 5

[0109] In the first conduction stage, the isolation valve Vs is opened, the current source circuit 10 provides a conduction current for the controllable commutation thyristor 50, and the controllable commutation thyristor 50 is turned on. Then the conduction current decreases, and when the conduction current decreases but has not yet decreased to 0, the first controllable valve V1 in the active turn-off circuit 30 is turned on, the first capacitor C1 discharges to the controllable commutation thyristor 50 through the first inductor L1 and the second inductor L2 (wherein the first capacitor C1 has been pre-charged before the first controllable valve V1 is turned on, and the first DC power supply 31 pre-charges the first capacitor C1), to provide a turn-off test current, the current flowing through the controllable commutation thyristor 50 gradually increases, until the amplitude of the turn-off test current reaches a first set value, at which time the controllable commutation thyristor 50 is actively turned off, the first controllable valve V1 is turned off, and the first stage ends.

[0110] In the active turn-off stage, after the controllable commutation thyristor 50 is actively turned off, due to the presence of the first inductor L1, the turn-off test current is not immediately 0, but gradually decreases. In this process, the overcharge current provided by the first inductor L1 charges the third capacitor C3, and the third capacitor C3 provides a positive support voltage for the controllable commutation thyristor 50, so that the controllable commutation thyristor 50 is reversely recovered. Until the current provided by the first inductor L1 is consumed, the controllable commutation thyristor 50 reversely recovers and ends. Then, due to the presence of the support voltage on the third capacitor C3, the controllable commutation thyristor 50 bears a forward voltage, and there is no current flowing through the controllable commutation thyristor 50, and the second stage ends.

[0111] ​In the first commutation stage, the sixth controllable valve V6 is turned on, the support voltage stored on the third capacitor C3 is discharged to the second capacitor C2 through the sixth controllable valve V6, the voltage on the controllable commutation valve 50 gradually decreases until the voltage on the controllable commutation valve 50 decreases to 0, then the fourth controllable valve V4 is controlled to be turned on and the third controllable valve V3 is controlled to be turned off, the second capacitor C2 and the fourth inductor L4 form a resonant circuit, resonance occurs, the second capacitor C2 is charged by the resonant circuit, so that the polarity of the second capacitor C2 is reversed (from positive to negative), the voltage on the second capacitor C2 is a negative voltage, and the voltage on the controllable commutation valve 50 is a gradually increasing negative voltage. Then the third controllable valve V3 is turned on and the fourth controllable valve V4 is turned off to charge the second capacitor C2, so that the polarity of the second capacitor C2 is reversed again (from negative to positive). Then the second controllable valve V2 is controlled to be turned on, the second DC power supply 21 pre-charges the second capacitor C2, and after the second capacitor C2 is fully charged, the third stage ends. At the end of the third stage, the fifth controllable valve V5 is turned off, and the connection between the voltage source circuit 20 and the controllable commutation valve 50 is cut off. The first stage workflow can be repeated next to enter the next cycle.

[0112] As can be seen from the above first commutation stage, by designing the fourth controllable valve V4, the active reversal of the voltage polarity on the second capacitor C2 can be achieved, which can make the voltage polarity on the second capacitor C2 consistent with the actual working condition. Since there is no active turn-off stage in the actual operation of the controllable commutation valve 50, and in the active turn-off stage, the third capacitor C3 provides a positive support voltage for the controllable commutation valve 50, so that the second capacitor C2 which should be discharged does not discharge, which is not consistent with the actual working condition. Therefore, the active reversal of the voltage polarity on the second capacitor C2 is needed by designing the fourth controllable valve V4, so that the voltage polarity on the second capacitor C2 is consistent with the actual working condition, and a more realistic actual working condition is simulated for the controllable commutation valve 50.

[0113] The process of the commutation-related test working condition can be described with reference to the waveform diagram of Figure 6 In the process of the commutation-related test working condition:

[0114] In the second conduction stage, the isolation valve Vs is opened, the current source circuit 10 provides a conduction current for the controllable commutation thyristor 50, and the controllable commutation thyristor 50 is in conduction. Then the conduction current decreases, and when the conduction current decreases but has not yet decreased to 0, the fifth controllable valve V5 in the voltage source circuit 20 is in conduction, the second capacitor C2 discharges to the controllable commutation thyristor 50 through the third inductor L3 (wherein the second capacitor C2 has been pre-charged before the fifth controllable valve V5 is in conduction, specifically, the second controllable valve V2 is in conduction, and the second DC power supply 21 pre-charges the second capacitor C2) (the voltage on the second capacitor C2 at this time is defined as a positive voltage), and a sinusoidal current is generated on the controllable commutation thyristor 50. When the sinusoidal current passes 0, the sixth controllable valve V6 is in conduction, at this time the current direction changes, the controllable commutation thyristor 50 commutates, and the first stage ends. In the first stage, since the controllable commutation thyristor 50 is in conduction, the voltage on the controllable commutation thyristor 50 is very small.

[0115] In the commutation stage, after the sinusoidal current passes 0, the polarity of the second capacitor C2 is reversed (from positive to negative), at this time the sixth controllable valve V6 is in conduction, the second capacitor C2 continues to provide a reverse sinusoidal current for the controllable commutation thyristor 50, and there is a reverse recovery voltage on the controllable commutation thyristor 50, so that the controllable commutation thyristor 50 reversely recovers, and when the reverse sinusoidal current is 0, the reverse recovery of the controllable commutation thyristor 50 ends, the controllable commutation thyristor 50 bears a reverse voltage, and there is no current on the controllable commutation thyristor 50, and the second stage ends.

[0116] In the second commutation stage, the third controllable valve V3 is in conduction, the second capacitor C2 and the fourth inductor L4 form a resonance circuit, resonance occurs, the second capacitor C2 is charged by the resonance circuit, the polarity of the second capacitor C2 is reversed again (from negative to positive), and then the second capacitor C2 provides a positive voltage for the controllable commutation thyristor 50, so that the voltage on the controllable commutation thyristor 50 is reversed from negative to positive. The voltage on the controllable commutation thyristor 50 is reversed, then the second controllable valve V2 is controlled to be in conduction, the second DC power supply 21 pre-charges and supplements the energy of the second capacitor C2, and after the second capacitor C2 is fully supplemented with energy, the third stage ends. At the end of the third stage, the fifth controllable valve V5 is turned off, and the connection between the voltage source circuit 20 and the controllable commutation thyristor 50 is cut off. Next, the workflow of the first stage can be repeated to enter the next cycle.

[0117] In the present embodiment, a complete test process of the active turn-off test working condition and a complete test process of the commutation turn-off test working condition are provided. By using the test device of the present application, the active turn-off test working condition and the commutation turn-off test working condition can be simulated for the controllable commutation thyristor 50, and the test experiment of the controllable commutation thyristor 50 is realized.

[0118] In one embodiment, as shown in Figure 7 The test device of the commutation thyristor further comprises an impulse voltage circuit 60, which is connected with the controllable commutation thyristor 50 and used to provide an impulse voltage for the controllable commutation thyristor 50.

[0119] The impulse voltage circuit 60 comprises an impulse generator 61 and an impulse test switch S. The first end of the impulse generator 61 is provided with a ball gap with the first end of the impulse test switch S, the second end of the impulse generator 61 is connected with the negative electrode of the controllable commutation thyristor 50, and the second end of the impulse test switch S is connected with the positive electrode of the controllable commutation thyristor 50.

[0120] The impulse generator 61 can provide an impulse voltage for the controllable commutation thyristor 50 in the recovery period transient forward voltage test of the controllable commutation thyristor 50.

[0121] For example, the impulse generator 61 can also be used for lightning impulse voltage full-wave, lightning impulse voltage chopped-wave and operating impulse voltage wave impulse voltage test of a test object such as a power device to test the insulation performance thereof.

[0122] The ball gap is an air gap of slightly uneven electric field composed of a pair of metal ball electrodes with the same diameter. It is mainly used to measure the peak value of high voltage and can also be used as a protection gap.

[0123] In the embodiment, the impulse voltage circuit 60 is provided to provide an impulse voltage to both ends of the controllable commutation thyristor 50, so as to test the controllable commutation thyristor 50 and test whether the reliability of the controllable commutation thyristor 50 under the impulse voltage meets the standard.

[0124] In one embodiment, as shown in Figure 8 The test device of the commutation thyristor further comprises a fault current circuit 70, which is connected with the controllable commutation thyristor 50 and used to provide a fault current for the controllable commutation thyristor 50.

[0125] The fault current circuit 70 comprises a fault power supply 71, a fourth capacitor C4, a fifth inductor L5 and a seventh controllable valve V7. The fault power supply 71 is connected in parallel with the fourth capacitor C4. The first end of the fifth inductor L5 is connected with the first end of the fourth capacitor C4. The second end of the fifth inductor L5 is connected with the positive electrode of the seventh controllable valve V7. The negative electrode of the seventh controllable valve V7 is connected with the positive electrode of the controllable commutation thyristor 50. The second end of the fourth capacitor C4 is connected with the negative electrode of the controllable commutation thyristor 50.

[0126] The fault power supply 71 is used to simulate output of various fault currents. The fault current circuit 70 is powered by a low-voltage large-capacity capacitor and outputs a sine half-wave current with an amplitude of 30kA~60kA and a pulse width of 16~20ms.

[0127] Wherein, the fault current can be any abnormal current. For example, a short circuit is a fault in which a live wire contacts a neutral or ground wire, and an open circuit fault occurs if the circuit is interrupted due to a fault in the current carrying wire (phase or neutral) or a blown fuse or circuit breaker. In a three-phase system, the fault can involve one or more phases and ground, or can occur only between phases, in a "ground fault" or "earth fault", current flows into the ground, and a fault current is generated in the circuit.

[0128] In this embodiment, by setting the fault current circuit 70, the controllable commutation thyristor 50 can be provided with a fault current, so as to test the controllable commutation thyristor 50 and verify whether the reliability of the controllable commutation thyristor 50 meets the standard in the case of a fault current.

[0129] In one embodiment, as shown in Figure 9 A testing method of a controllable commutation thyristor is provided, the method is applied to the testing device of the controllable commutation thyristor in the above embodiment, and the method comprises steps S900-S930.

[0130] Step S900, the working states of the current source circuit and the voltage source circuit are controlled respectively, and the controllable commutation thyristor is simulated in a commutation off test working condition.

[0131] Step S910, the working states of the current source circuit, the voltage source circuit and the active off test circuit are controlled respectively, and the controllable commutation thyristor is simulated in an active off test working condition in the case that the amplitude of the off test current reaches a first set value.

[0132] Step S920, the electrical parameters of the controllable commutation thyristor in the target test working condition are obtained.

[0133] Wherein, the target test working condition comprises at least one of the active off test working condition and the commutation off test working condition.

[0134] Step S930, the test result of the controllable commutation thyristor is determined based on the electrical parameters.

[0135] In the embodiment, the working states of the current source circuit, the voltage source circuit and the active blocking circuit are controlled respectively, so as to simulate the target test working condition for the controllable phase-changing converter valve, that is, the current source circuit and the voltage source circuit can be used to simulate the phase-changing blocking test working condition for the controllable phase-changing converter valve, and then the electrical parameters of the controllable phase-changing converter valve in the phase-changing blocking test working condition can be collected, and the current source circuit, the voltage source circuit and the active blocking circuit can be used to simulate the active blocking test working condition for the controllable phase-changing converter valve, so that the electrical parameters of the controllable phase-changing converter valve in the active blocking test working condition can be collected. The test result of the controllable phase-changing converter valve can be determined through the collected electrical parameters, and then the performance and reliability of the controllable phase-changing converter valve can be judged, and the test on the controllable phase-changing converter valve is realized.

[0136] In one embodiment, as shown in FIG. 10, step S910, the working states of the current source circuit, the voltage source circuit and the active blocking test circuit are controlled respectively, and the active blocking of the controllable phase-changing converter valve is controlled in the case that the amplitude of the blocking test current reaches the first set value, so as to simulate the active blocking test working condition for the controllable phase-changing converter valve. This includes steps S1000-S1020. Figure 10

[0137] Step S1000, the current source circuit is controlled to provide the on-state current for the controllable phase-changing converter valve, the active blocking circuit is controlled to provide the blocking test current for the controllable phase-changing converter valve, and the active blocking of the controllable phase-changing converter valve is controlled in the case that the amplitude of the blocking test current reaches the first set value, so as to simulate the first conduction phase.

[0138] Step S1010, the active blocking circuit is controlled to provide the support voltage for the controllable phase-changing converter valve, so as to simulate the active blocking phase.

[0139] Step S1020, the voltage source circuit is controlled to provide the phase-changing voltage for the controllable phase-changing converter valve, so as to simulate the first phase-changing phase.

[0140] In the embodiment, a test method in the active blocking test working condition is provided, which can simulate the active blocking test working condition for the controllable phase-changing converter valve, and verify the performance and reliability of the controllable phase-changing converter valve in the active blocking test working condition.

[0141] It should be understood that, although Figure 9 , 10 the steps in the flowcharts are displayed in sequence according to the arrows, these steps are not necessarily executed in sequence according to the arrows. Unless otherwise specified in this article, the execution of these steps has no strict sequence limitation, and these steps can be executed in other sequences. Moreover, Figure 9 , 10 ​At least one of the steps in the above-mentioned embodiments can include a plurality of steps or a plurality of stages, which are not necessarily performed at the same time, but can be performed at different times, and the order of the steps or stages is not necessarily sequential, but can be performed alternately or alternately with at least one of the other steps or steps in the other steps.

[0142] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing related hardware through a computer program, and the computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments of each method. Wherein, any reference to memory, storage, database or other medium used in each embodiment provided by the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (Read-Only Memory, ROM), magnetic tape, floppy disk, flash memory or optical memory, etc. Volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (Static Random Access Memory, SRAM) or dynamic random access memory (Dynamic Random Access Memory, DRAM), etc.

[0143] In the description of the present specification, the description of the terms "some embodiments", "other embodiments", "ideal embodiments" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above-mentioned terms does not necessarily refer to the same embodiment or example.

[0144] The technical features of the above embodiments can be combined in any way. In order to make the description simple, not all possible combinations of the technical features in the above embodiments are described, but as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present specification.

[0145] The above-mentioned embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of the patent of the present application should be subject to the appended claims.

Claims

1. A testing device for a controllable commutation valve, characterized in that, The device includes: The current source circuit, voltage source circuit, and active shutdown circuit are respectively connected to the controllable commutation valve. A processing module, connected to the current source circuit, the voltage source circuit, the active shutdown circuit, and the controllable commutator valve, respectively, is used to control the operating states of the current source circuit, the voltage source circuit, and the active shutdown circuit, simulate a target test condition for the controllable commutator valve, and collect the electrical parameters of the controllable commutator valve under the target test condition. These electrical parameters are used to determine the test results of the controllable commutator valve. The target test condition includes at least one of an active shutdown test condition and a commutator shutdown test condition. The test operation includes a first conduction stage, an active turn-off stage, and a first commutation stage. The processing module controls the current source circuit to provide on-state current to the controllable commutation valve and controls the active turn-off circuit to provide turn-off test current to the controllable commutation valve to simulate the first conduction stage. The controllable commutation valve is actively turned off, and the active turn-off circuit provides a supporting voltage to the controllable commutation valve to simulate the active turn-off stage. The processing module controls the voltage source circuit to provide commutation voltage to the controllable commutation valve to simulate the first commutation stage. The active shutdown circuit includes a first DC power supply, a first energy storage unit, a first switching unit, and a first discharge output unit, wherein: the first DC power supply is connected in parallel with the first energy storage unit to charge the first energy storage unit; the first energy storage unit is used to store electrical energy; the first switching unit is connected in series between the positive terminal of the controllable commutation valve and the first energy storage unit to control the opening or closing of the path between the positive terminal of the controllable commutation valve and the first energy storage unit; the first discharge output unit is connected in series between the positive terminal of the controllable commutation valve and the first energy storage unit so that the first energy storage unit provides a stable shutdown test current to the controllable commutation valve.

2. The testing device for the controllable commutation valve according to claim 1, characterized in that, The first energy storage unit includes a first capacitor; the first switching unit includes a first controllable valve; and the first discharge output unit includes a first inductor, a second inductor, and a freewheeling diode. The first capacitor is connected in parallel with the first DC power supply. The positive terminal of the first controllable valve is connected to the first terminal of the first capacitor, and the negative terminal of the first controllable valve is connected to the first terminal of the first inductor. The second terminal of the first inductor is connected to the positive terminal of the controllable commutation valve, and the second terminal of the first capacitor is connected to the negative terminal of the controllable commutation valve. The second inductor is connected in series between the positive terminal of the first controllable valve and the first terminal of the first capacitor. The positive terminal of the freewheeling diode is connected to the positive terminal of the first controllable valve, and the negative terminal of the freewheeling diode is connected to the first terminal of the first capacitor. The first controllable valve is used to turn on during the test of the active turn-off performance of the controllable commutation valve, so that the first capacitor discharges to the controllable commutation valve through the first inductor to provide the turn-off test current. The controllable commutation valve is used to actively shut off when the amplitude of the shutdown test current reaches a first set value.

3. The testing device for the controllable commutation valve according to claim 1, characterized in that, The voltage source circuit includes: a second DC power supply, a second switching unit, a voltage polarity reversal unit, a second energy storage unit, a commutation unit, a second discharge output unit, and a third energy storage unit. The positive terminal of the second DC power supply is connected to the first terminal of the second switching unit, the second terminal of the second switching unit is connected to the first terminal of the voltage polarity reversal unit, the negative terminal of the second DC power supply is connected to the second terminal of the voltage polarity reversal unit and the negative terminal of the controllable commutation valve, the second energy storage unit is connected in parallel with the voltage polarity reversal unit, the commutation unit is connected in series between the second energy storage unit and the positive terminal of the controllable commutation valve, the second discharge output unit is connected in series between the second energy storage unit and the positive terminal of the controllable commutation valve, and the third energy storage unit is connected in parallel with the controllable commutation valve. The voltage polarity reversal unit is used to adjust the polarity of the voltage on the second energy storage unit; The commutation unit is used to adjust the polarity of the voltage applied to the controllable commutation valve.

4. The testing device for the controllable commutation valve according to claim 3, characterized in that, The second switching unit includes a second controllable valve, the second energy storage unit includes a second capacitor, the third energy storage unit includes a third capacitor, and the second discharge output unit includes a third inductor. The positive terminal of the second DC power supply is connected to the positive terminal of the second controllable valve, the negative terminal of the second controllable valve is connected to the first terminal of the voltage polarity reversal unit, the negative terminal of the second DC power supply is connected to the second terminal of the voltage polarity reversal unit and the negative terminal of the controllable commutation valve, the second capacitor is connected in parallel with the voltage polarity reversal unit, the first terminal of the commutation unit is connected to the first terminal of the second capacitor, the second terminal of the commutation unit is connected to the first terminal of the third inductor, the second terminal of the third inductor is connected to the positive terminal of the controllable commutation valve, and the third capacitor is connected in parallel with the controllable commutation valve.

5. The testing device for the controllable commutation valve according to claim 4, characterized in that, The voltage polarity reversal unit includes: a fourth inductor, a third controllable valve, and a fourth controllable valve. The first end of the fourth inductor is connected to the negative terminal of the second controllable valve. The second end of the fourth inductor is connected to the first end of the commutation unit and the first end of the second capacitor. The second end of the second capacitor is connected to the negative terminal of the second DC power supply. The positive terminal of the third controllable valve is connected to the negative terminal of the fourth controllable valve and the negative terminal of the second DC power supply. The negative terminal of the third controllable valve is connected to the positive terminal of the fourth controllable valve and the first end of the fourth inductor. The third and fourth controllable valves are used for time-division multiplexing to adjust the polarity of the voltage on the second capacitor.

6. The testing apparatus for the controllable commutation valve according to claim 4, characterized in that, The commutation unit includes: a fifth controllable valve and a sixth controllable valve, wherein the positive terminal of the fifth controllable valve is connected to the negative terminal of the sixth controllable valve and the first terminal of the second capacitor, and the negative terminal of the fifth controllable valve is connected to the positive terminal of the sixth controllable valve and the first terminal of the third inductor. The fifth and sixth controllable valves are used for time-division multiplexing to adjust the polarity of the voltage applied to the controllable commutation valve.

7. The testing apparatus for the controllable commutation valve according to claim 1, characterized in that, The current source circuit includes a power supply and a rectifier-inverter coupled circuit. The rectifier-inverter coupled circuit is connected to the power supply and the controllable commutation valve, respectively. The rectifier-inverter coupled circuit is used to apply the equivalent current stress of the controllable commutation valve under the power supply of the power supply.

8. The testing apparatus for the controllable commutation valve according to claim 7, characterized in that, The device further includes an isolation valve, which is connected to the rectifier-inverter circuit and the controllable commutation valve respectively. The isolation valve is used to isolate the rectifier-inverter circuit from the controllable commutation valve.

9. The testing apparatus for the controllable commutation valve according to claim 8, characterized in that, The isolation valve includes a reverse-resistance integrated gate commutator thyristor.

10. The testing apparatus for the controllable commutation valve according to any one of claims 1-9, characterized in that, The testing device for the controllable commutation valve also includes: An impulse voltage circuit, connected to a controllable commutation valve, is used to provide an impulse voltage to the controllable commutation valve.

11. The testing apparatus for the controllable commutation valve according to claim 10, characterized in that, The impulse voltage circuit includes: an impulse generator and an impulse test switch. A ball gap is provided between the first end of the impulse generator and the first end of the impulse test switch. The second end of the impulse generator is connected to the negative terminal of the controllable commutation valve, and the second end of the impulse test switch is connected to the positive terminal of the controllable commutation valve.

12. The testing apparatus for the controllable commutation valve according to any one of claims 1-9, characterized in that, The testing device for the controllable commutation valve also includes: A fault current circuit, connected to the controllable commutation valve, is used to provide fault current to the controllable commutation valve.

13. The testing apparatus for the controllable commutation valve according to claim 12, characterized in that, The fault current circuit includes: a fault power supply, a fourth capacitor, a fifth inductor, and a seventh controllable valve. The fault power supply is connected in parallel with the fourth capacitor. The first terminal of the fifth inductor is connected to the first terminal of the fourth capacitor. The second terminal of the fifth inductor is connected to the positive terminal of the seventh controllable valve. The negative terminal of the seventh controllable valve is connected to the positive terminal of the controllable commutation valve. The second terminal of the fourth capacitor is connected to the negative terminal of the controllable commutation valve.

14. A test method for a controllable commutation valve, characterized in that, The method is applied to the test apparatus for the controllable commutation valve as described in any one of claims 1-13, and the method includes: The operating states of the current source circuit and the voltage source circuit are controlled respectively to simulate the commutation disconnection test conditions for the controllable commutation valve. The operating states of the current source circuit, the voltage source circuit, and the active shutdown circuit are controlled respectively, and the controllable commutation valve is actively shut off when the amplitude of the shutdown test current reaches a first set value, thereby simulating the active shutdown test condition for the controllable commutation valve. Obtain the electrical parameters of the controllable commutation valve under the target test conditions, wherein the target test conditions include at least one of the active shutdown test conditions and the commutation shutdown test conditions; The test results of the controllable commutation valve are determined based on the electrical parameters.

15. The test method for the controllable commutation valve according to claim 14, characterized in that, The active shutdown test condition includes a first conduction phase, an active shutdown phase, and a first commutation phase; the control of the operating states of the current source circuit, the voltage source circuit, and the active shutdown circuit, and the controllable commutation valve being actively shut off when the amplitude of the shutdown test current reaches a first set value, simulates the active shutdown test condition for the controllable commutation valve, including: The current source circuit is controlled to provide on-state current to the controllable commutator valve, the active shutdown circuit is controlled to provide shutdown test current to the controllable commutator valve, and the controllable commutator valve is controlled to actively shut down when the amplitude of the shutdown test current reaches a first set value, so as to simulate the first conduction stage. The controllable commutation valve is actively shut off, and the active shutdown circuit provides a supporting voltage to the controllable commutation valve to simulate the active shutdown stage. The voltage source circuit is controlled to provide commutation voltage to the controllable commutation valve to simulate the first commutation stage.

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