A test circuit and a test method for a thyristor stage control circuit of a converter valve

Abstract

The application provides a test circuit and a test method for a thyristor stage control circuit of a converter valve, and the test circuit comprises: a power supply side circuit and a load side circuit, the power supply side circuit is connected with the load side circuit, and the power supply side circuit is used for reproducing voltages and currents under actual operation conditions for a measured thyristor stage in the load side circuit; and the power supply side circuit comprises: a plurality of parallel bridge arms, each bridge arm comprises a plurality of cascaded H-bridge circuits. By tracking a target voltage and current waveform, the number of cascaded H-bridge circuits in each bridge arm is controlled according to the target voltage waveform, and the voltage across the measured thyristor stage when the thyristor stage is turned off under the actual operation condition is reproduced. According to the target voltage and current waveform, the number of parallel bridge arms is controlled, and the on-state current of the measured thyristor stage when the thyristor stage is turned on under the actual operation condition is reproduced, and then the compatibility of the thyristor stage control circuit is tested according to the actual operation condition.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power system devices, in particular to a test circuit and a test method for a thyristor level control circuit of a converter valve. BACKGROUND

[0002] The core equipment of a high voltage direct current transmission based on a grid commutated converter is a converter valve, which is composed of key primary and secondary components such as thyristors and their control circuits, damping capacitors, etc. The thyristor level control circuit is equivalent to the "brain" of the converter valve, which is responsible for controlling the triggering of the thyristor and state monitoring. The thyristor level control circuit is adjacent to the high voltage primary circuit, and the high voltage primary circuit generates high voltage rate of change and current rate of change when operating, and the transient change of the space strong electromagnetic field will interfere with the normal operation of the thyristor level control circuit, so it is necessary to simulate the voltage and current changes during the operation of the converter valve to test the reliability of the thyristor level control circuit.

[0003] The prior art mainly simulates the voltage and current changes during the operation of the converter valve by synthesizing a test circuit, but the waveform is quite different from the actual operation, which only simply simulates the amplitude and effective value, and does not reproduce the actual change process. Therefore, the electromagnetic compatibility of the thyristor level control circuit is not fully tested according to the actual operating conditions. SUMMARY

[0004] Therefore, the technical problem to be solved by the present application is to overcome the defect that the electromagnetic compatibility of the thyristor level control circuit is not fully tested according to the actual operating conditions in the prior art, so as to provide a test circuit and a test method for a thyristor level control circuit of a converter valve.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0006] In a first aspect, the present application provides a test circuit for a thyristor level control circuit of a converter valve, comprising: a power supply side circuit and a load side circuit, the power supply side circuit being connected with the load side circuit, the power supply side circuit being used for reproducing the voltage and current under actual operating conditions for a measured thyristor level in the load side circuit;

[0007] The power supply side circuit comprises a plurality of parallel bridge arms, each bridge arm comprising a plurality of cascaded H-bridge circuits;

[0008] The power supply side circuit reproduces the on-state current of the measured thyristor level under actual operating conditions by controlling the number of parallel bridge arms, and reproduces the voltage across the measured thyristor level under actual operating conditions by controlling the number of cascaded H-bridge circuits in each bridge arm.

[0009] Optionally, the load side circuit comprises at least one measured thyristor stage, and the measured thyristor stage is connected in series.

[0010] Optionally, the measured thyristor stage comprises a thyristor, a damping circuit and a thyristor stage control unit, wherein,

[0011] a first end of the thyristor is connected to a first end of the damping circuit, a second end of the thyristor is connected to a second end of the damping circuit, and a control end of the thyristor is connected to the thyristor stage control unit.

[0012] Optionally, the damping circuit comprises a first inductor, a first resistor and a first capacitor, wherein,

[0013] a first end of the first inductor is connected to a first end of the power supply side circuit, and a second end of the first inductor is connected to a first end of the thyristor and a first end of the first resistor, respectively;

[0014] a second end of the first resistor is connected to a first end of the first capacitor, and a second end of the first capacitor is connected to a second end of the thyristor and a second end of the power supply side circuit.

[0015] Optionally, each bridge arm further comprises a bridge arm inductor, and the bridge arm inductor is connected in series to the plurality of cascaded H-bridge circuits.

[0016] Optionally, the H-bridge circuit is connected to a programmable control unit, and the programmable control unit sends on-off control instructions to all-controlling devices in the H-bridge circuit according to a preset control logic and timing.

[0017] In a second aspect, an embodiment of the present application provides a test method for a thyristor stage control circuit of a converter valve, based on the test circuit for the thyristor stage control circuit of the converter valve according to the first aspect of the present application, the test method for the thyristor stage control circuit of the converter valve comprises:

[0018] acquiring a target voltage and a target on-state current across the measured thyristor stage;

[0019] controlling a number of cascaded H-bridge circuits in each bridge arm according to the target voltage;

[0020] controlling a number of parallel bridge arms according to the target on-state current.

[0021] Optionally, the controlling the number of cascaded H-bridge circuits in each bridge arm according to the target voltage comprises:

[0022] generating a first conduction timing control logic according to the target voltage;

[0023] According to the first conduction timing control logic, a first control instruction of turning on or turning off the full-controlled device of the H-bridge circuit in each bridge arm is sent out;

[0024] According to the first control instruction, the number of cascaded H-bridge circuits in each bridge arm is controlled.

[0025] Optionally, the control of the number of parallel bridge arms according to the target on-state current comprises:

[0026] A second conduction timing control logic is generated according to the target on-state current;

[0027] According to the second conduction timing control logic, a second control instruction of turning on or turning off the full-controlled device of the H-bridge circuit in each bridge arm is sent out;

[0028] According to the second control instruction, the number of parallel bridge arms is controlled.

[0029] The technical scheme of the present application has the following advantages:

[0030] The test circuit for the thyristor stage control circuit of the converter valve provided by the present application comprises: a power supply side circuit and a load side circuit, the power supply side circuit is connected with the load side circuit, and the power supply side circuit is used for reproducing the voltage and current under the actual operation condition for the measured thyristor stage in the load side circuit; the power supply side circuit comprises: a plurality of parallel bridge arms, each bridge arm comprises a plurality of cascaded H-bridge circuits. Unlike the waveform approximation simulation of the synthetic test circuit, the present application tracks the target voltage and current waveform, controls the number of cascaded H-bridge circuits in each bridge arm according to the target voltage waveform, and reproduces the voltage at both ends of the measured thyristor stage when the thyristor stage is turned off under the actual operation condition. According to the target voltage and current waveform, the number of parallel bridge arms is controlled, and the on-state current of the measured thyristor stage when the thyristor stage is turned on under the actual operation condition is reproduced, and then the compatibility of the thyristor stage control circuit under the actual operation condition is examined.

[0031] The test method for the thyristor stage control circuit of the converter valve provided by the present application tracks the target voltage and current waveform, controls the number of cascaded H-bridge circuits in each bridge arm according to the target voltage waveform, and reproduces the voltage at both ends of the measured thyristor stage when the thyristor stage is turned off under the actual operation condition. According to the target voltage and current waveform, the number of parallel bridge arms is controlled, and the on-state current of the measured thyristor stage when the thyristor stage is turned on under the actual operation condition is reproduced, and then the compatibility of the thyristor stage control circuit under the actual operation condition is examined. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the specific embodiments or prior art description. Obviously, the drawings described below are only some embodiments of the present application, and the ordinary skilled in the art can obtain other drawings according to these drawings without any creative effort.

[0033] Figure 1 A test circuit diagram for a thyristor level control circuit of a converter valve in an embodiment of the present application;

[0034] Figure 2 A flow chart of one specific example of a test method for a thyristor level control circuit of a converter valve in an embodiment of the present application. DETAILED DESCRIPTION

[0035] The technical solutions of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the ordinary skilled in the art without any creative effort are within the scope of protection of the present application.

[0036] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0037] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication between two elements, it can be wireless connection, or it can be wired connection. For the ordinary skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as there is no conflict between them.

[0039] The existing technology does not fully examine the electromagnetic compatibility of the thyristor-level control circuit according to the actual operation condition, only simply simulates the amplitude and effective value, and does not reproduce the actual change process. Therefore, the embodiment of the present application provides a test circuit for a thyristor-level control circuit of a converter valve, which reproduces the voltage and current change under the operation condition of the converter valve to complete the examination of the compatibility of the thyristor-level control circuit.

[0040] In an embodiment, as shown in Figure 1 A test circuit for a thyristor-level control circuit of a converter valve includes: a power supply side circuit and a load side circuit, the power supply side circuit being connected with the load side circuit. The power supply side circuit is used to reproduce the voltage and current under the actual operation condition for the measured thyristor-level in the load side circuit.

[0041] In a specific embodiment, the power supply side circuit includes: a plurality of parallel bridge arms. The more the parallel bridge arms, the greater the current amplitude that can be provided. Each bridge arm includes a bridge arm inductance L and a plurality of cascaded H-bridge circuits, the bridge arm inductance L being connected in series with the plurality of cascaded H-bridge circuits. The more the cascaded H-bridge circuits, the greater the voltage amplitude that can be provided.

[0042] In the embodiment of the present application, since the current amplitude is related to the number of parallel bridge arms, the power supply side circuit reproduces the on-state current of the measured thyristor-level under the actual operation condition by controlling the number of parallel bridge arms. Since the voltage amplitude is related to the number of cascaded H-bridge circuits, the power supply side circuit reproduces the voltage across the measured thyristor-level under the actual operation condition by controlling the number of cascaded H-bridge circuits in each bridge arm.

[0043] The present application provides a test circuit for a thyristor-level control circuit of a converter valve, which includes: a power supply side circuit and a load side circuit, the power supply side circuit being connected with the load side circuit, the power supply side circuit being used to reproduce the voltage and current under the actual operation condition for the measured thyristor-level in the load side circuit; the power supply side circuit includes: a plurality of parallel bridge arms, each bridge arm including a plurality of cascaded H-bridge circuits. Unlike the approximate simulation of the waveform of the synthetic test circuit, the present application reproduces the voltage across the measured thyristor-level under the actual operation condition by tracking the target voltage and current waveform, controlling the number of cascaded H-bridge circuits in each bridge arm according to the target voltage waveform. The present application reproduces the on-state current of the measured thyristor-level under the actual operation condition by controlling the number of parallel bridge arms according to the target voltage and current waveform, and further completes the examination of the compatibility of the thyristor-level control circuit according to the actual operation condition.

[0044] In an embodiment, the H-bridge circuit is composed of four fully controlled devices and diodes and DC capacitors connected in anti-parallel with the fully controlled devices.

[0045] In one specific embodiment, in order to control all the controlled devices in the H-bridge circuit, the H-bridge circuit is connected to a programmable control unit, which issues on / off control commands to the all controlled devices in the H-bridge circuit according to preset control logic and timing.

[0046] In one embodiment, the load-side circuit includes at least one thyristor stage under test, wherein the thyristor stages under test are connected in series.

[0047] In one specific embodiment, the load-side circuit consists of several thyristor stages under test connected in series. The number of stages connected in series depends on the requirements and the maximum voltage that the power supply-side circuit can provide, and is not limited here. Figure 1 The medium-load side circuit is illustrated using only one thyristor stage under test as an example.

[0048] In one embodiment, such as Figure 1 As shown, the thyristor T stage under test includes: thyristor T, damping circuit and thyristor stage control unit, wherein the first end of thyristor T is connected to the first end of damping circuit, the second end of thyristor T is connected to the second end of damping circuit, and the control end of thyristor T is connected to thyristor T stage control unit.

[0049] In one specific embodiment, the damping circuit includes: a first inductor L1, a first resistor R1, and a first capacitor C1, wherein the first end of the first inductor L1 is connected to the first end of the power supply side circuit, the second end of the first inductor L1 is connected to the first end of the thyristor T and the first end of the first resistor R1 respectively; the second end of the first resistor R1 is connected to the first end of the first capacitor C1, and the second end of the first capacitor C1 is connected to the second end of the thyristor T and then connected to the second end of the power supply side circuit.

[0050] This invention also provides a test method for a thyristor-level control circuit of a converter valve, based on the above-described test circuit for a thyristor-level control circuit of a converter valve, such as... Figure 2 The test method for the thyristor stage control circuit of the converter valve, as shown, includes the following steps:

[0051] Step S1: Obtain the target voltage and target on-state current across the thyristor stage under test.

[0052] Step S2: Control the number of cascaded H-bridge circuits in each bridge arm according to the target voltage at both ends.

[0053] Step S3: Control the number of parallel bridge arms according to the target on-state current.

[0054] In a specific embodiment, since the voltage amplitude is related to the number of cascaded H-bridge circuits, to realize the reproduction of the voltage waveform across the thyristor stage to be tested at the time of turn-off. First, according to the target voltage waveform, the number of H-bridge circuits to be turned on at each time for each bridge arm is calculated, which is equivalent to controlling the input voltage. According to the parameter configuration circuit, the steady state will be reached soon, and the voltage across the thyristor stage to be tested will reach the input voltage of the bridge arm soon. Therefore, through the switching control of the H-bridge circuit, the voltage across the thyristor stage to be tested can well track the target waveform, and the waveform reproduction is realized. It can be seen that each bridge arm of the thyristor stage to be tested at the time of turn-off is equivalent to a programmable voltage source. Specifically, the number of parallel bridges is accurately controlled in the following way: generate a first conduction timing control logic according to the target voltage; issue a first control instruction of turning on or off to the fully controlled devices of the H-bridge circuit in each bridge arm according to the first conduction timing control logic; and control the number of cascaded H-bridge circuits in each bridge arm according to the first control instruction.

[0055] Since the current amplitude is related to the number of parallel bridges, to realize the reproduction of the on-state current at the time of turn-on of the thyristor stage to be tested. According to the target on-state current waveform, the number of parallel bridges to be turned on at each time is calculated, and the number of parallel bridges to be turned on is accurately controlled through the switching control of the H-bridge circuit in each bridge arm. The target current waveform of the main circuit is realized by using the LC oscillation of each bridge arm and the current superposition of each bridge arm. It can be seen that each bridge arm of the thyristor at the time of turn-on is equivalent to a programmable current source. Specifically, the number of cascaded H-bridge circuits in each bridge arm is accurately controlled in the following way: generate a second conduction timing control logic according to the target on-state current; issue a second control instruction of turning on or off to the fully controlled devices of the H-bridge circuit in each bridge arm according to the second conduction timing control logic; and control the number of parallel bridges according to the second control instruction.

[0056] The present application provides a test method for a thyristor stage control circuit of a converter valve, which tracks the target voltage and current waveform, controls the number of cascaded H-bridge circuits in each bridge arm according to the target voltage waveform, and reproduces the voltage across the thyristor stage to be tested at the time of turn-off under actual operating conditions. According to the target voltage and current waveform, the number of parallel bridges is controlled, and the on-state current of the thyristor stage to be tested at the time of turn-on under actual operating conditions is reproduced, and then the compatibility of the thyristor stage control circuit is evaluated according to the actual operating conditions.

[0057] Obviously, the above embodiments are only examples for clear illustration, and are not limitations on the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments cannot be exhausted, and the obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A test circuit for a thyristor-stage control circuit of a converter valve, characterized in that, include: The power supply side circuit and the load side circuit are connected. The power supply side circuit is used to reproduce the voltage and current under actual operating conditions for the thyristor stage under test in the load side circuit. The power supply side circuit includes: multiple parallel bridge arms, each of the bridge arms including multiple cascaded H-bridge circuits; The power supply side circuit reproduces the on-state current of the tested thyristor stage when it is turned on under actual operating conditions by controlling the number of parallel connections of the bridge arms, and reproduces the voltage across the tested thyristor stage when it is turned off under actual operating conditions by controlling the number of cascaded H-bridge circuits in each bridge arm. Each of the bridge arms further includes: a bridge arm inductor, which is connected in series with multiple cascaded H-bridge circuits; The load-side circuit includes at least one thyristor stage under test, wherein the thyristor stages under test are connected in series.

2. The test circuit for the thyristor stage control circuit of the converter valve according to claim 1, characterized in that, The tested thyristor stage includes: a thyristor, a damping circuit, and a thyristor stage control unit, wherein... The first end of the thyristor is connected to the first end of the damping circuit, the second end of the thyristor is connected to the second end of the damping circuit, and the control end of the thyristor is connected to the thyristor-level control unit.

3. The test circuit for the thyristor stage control circuit of the converter valve according to claim 2, characterized in that, The damping circuit includes: a first inductor, a first resistor, and a first capacitor, wherein, The first end of the first inductor is connected to the first end of the power supply side circuit, and the second end of the first inductor is connected to the first end of the thyristor and the first end of the first resistor, respectively. The second end of the first resistor is connected to the first end of the first capacitor, and the second end of the first capacitor is connected to the second end of the thyristor and then to the second end of the power supply side circuit.

4. The test circuit for the thyristor stage control circuit of the converter valve according to claim 1, characterized in that, The H-bridge circuit is connected to a programmable control unit, which issues on / off control commands to all controlled devices in the H-bridge circuit according to preset control logic and timing.

5. A test method for a thyristor-stage control circuit of a converter valve, characterized in that, Based on the test circuit for the thyristor-level control circuit of the converter valve according to any one of claims 1-4, the test method for the thyristor-level control circuit of the converter valve includes: Obtain the target voltage and target on-state current across the thyristor stage under test; Based on the target voltages at both ends, control the number of cascaded H-bridge circuits in each bridge arm; The number of parallel bridge arms is controlled based on the target on-state current.

6. The test method for the thyristor stage control circuit of the converter valve according to claim 5, characterized in that, The step of controlling the number of cascaded H-bridge circuits in each bridge arm based on the target voltages at both ends includes: The first conduction timing control logic is generated based on the target voltages at both ends; According to the first conduction timing control logic, a first control command is issued to turn on or off the fully controlled device of the H-bridge circuit in each bridge arm. The number of H-bridge circuits cascaded in each bridge arm is controlled according to the first control command.

7. The test method for the thyristor stage control circuit of the converter valve according to claim 5, characterized in that, The step of controlling the number of parallel bridge arms based on the target on-state current includes: A second conduction timing control logic is generated based on the target on-state current; According to the second conduction timing control logic, a second control command is issued to turn on or off the fully controlled device of the H-bridge circuit in each bridge arm. The number of parallel bridge arms is controlled according to the second control command.

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