Flexible direct current converter valve destructive test method, device, equipment and medium

Abstract

The invention discloses a destructive test method, device, equipment and medium for a flexible direct-current converter valve, and the method comprises the steps: firstly constructing an IGBT test submodule according to the long-term through-current capability of an IGBT device in a flexible direct-current converter valve submodule; the device comprises a test object sub-module of which the IGBT has long-term through-current capability and a test object sub-module of which the IGBT does not have long-term through-current capability. Secondly, respectively carrying out upper and lower IGBT direct connection destructive tests on the two test object sub-modules, carrying out bypass switch false connection destructive tests on the test object sub-modules with IGBT long-term through-current capability, and respectively carrying out bypass switch refusal destructive tests on the two test object sub-modules; and finally, judging the explosion-proof performance of the flexible direct-current converter valve according to the test phenomenon of the test to obtain a test result. According to the invention, the requirement of the destructive test of the flexible direct-current converter valve can be better met, and the reliability of the test result is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible direct current power transmission, and in particular to a destructive test method, device, equipment and medium for a flexible direct current converter valve. Background Art

[0002] Flexible direct current transmission VSC-HVDC (Voltage Source Converter based High Voltage Direct Current, high voltage direct current transmission based on voltage source converter) is a direct current transmission technology with fully controlled devices such as IGBT (insulated gate bipolar transistor) as core power devices. Compared with conventional direct current transmission LCC-HVDC (Line Commutated Converter High Voltage Direct Current, high voltage direct current transmission based on grid commutated converter), it has advantages in reactive power compensation capability, no need for supporting power supply, no commutation failure and flexible power control. In the future, application scenarios such as distributed energy grid connection, AC grid back-to-back engineering, island system power supply, and deep sea wind power transmission will mainly use flexible direct current transmission as the external transmission channel. However, due to the current capacity of IGBT devices, the maximum DC current of flexible direct current projects built at home and abroad is only 3kA. With the gradual advancement of energy development, the demand for ultra-high voltage and large-capacity flexible direct current and its core converter valve equipment is becoming more and more urgent.

[0003] However, as the capacity of a single module increases, in addition to the improvement of the current flow performance of the IGBT device, the capacitance of the submodule increases, and the amplitude of the through-circuit current that may be caused by the breakdown of the power device under extreme fault conditions increases significantly. High voltage and high current may cause overvoltage breakdown and tube shell rupture of semiconductor devices, which may damage the power module and adjacent modules, making it impossible to reliably bypass the faulty module of the flexible DC valve. Therefore, it is very important to verify the protection performance of the flexible DC converter valve submodule under extreme fault conditions through experiments. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a destructive test method, device, equipment and medium for a flexible DC converter valve, so as to improve the rationality and accuracy of the protection performance detection of the flexible DC converter valve submodule and improve the reliability of flexible DC power transmission.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides a destructive test method for a flexible DC converter valve, comprising:

[0006] According to the long-term flow capacity of the IGBT device in the flexible DC converter valve submodule, an IGBT test submodule is constructed; wherein the IGBT test submodule includes a test submodule in which the IGBT has a long-term flow capacity and a test submodule in which the IGBT does not have a long-term flow capacity;

[0007] Performing upper and lower IGBT direct destructive tests on the test submodule with long-term current-carrying capacity of the IGBT and the test submodule without long-term current-carrying capacity of the IGBT respectively;

[0008] Conducting a bypass switch mis-closing destructive test on the test submodule of the IGBT with long-term current-carrying capacity;

[0009] Conducting a bypass switch refusal to operate destructive test on the test submodule of the IGBT with long-term current-carrying capacity and the test submodule of the IGBT without long-term current-carrying capacity respectively;

[0010] The explosion-proof performance of the flexible DC converter valve is judged based on the test phenomena of the upper and lower IGBT direct-through destructive test, the bypass switch misclosing destructive test and the bypass switch refusal to operate destructive test to obtain the test results.

[0011] As an improvement of the above scheme, the upper and lower IGBT straight-through destructive test, bypass switch misclosing destructive test and bypass switch refusal to operate destructive test all include overall assessment level destructive test and device assessment level destructive test.

[0012] Preferably, the overall assessment-level destructive test is conducted using a complete IGBT test submodule with long-term current-carrying capability / an IGBT test submodule without long-term current-carrying capability;

[0013] The device assessment level destructive test uses insulating gaskets or metal blocks or failed IGBT devices to replace the IGBT devices in the test submodule with long-term current-carrying capacity / IGBT test submodule without long-term current-carrying capacity to construct an equivalent test circuit for testing.

[0014] As an improvement of the above scheme, a 168-hour long-term current conduction test is performed on the test sub-module with long-term current conduction capability of the IGBT and the test sub-module without long-term current conduction capability according to the maximum operating current values ​​of the test sub-module with long-term current conduction capability of the IGBT and the test sub-module without long-term current conduction capability, respectively.

[0015] Preferably, the IGBT test submodule with long-term current-carrying capacity comprises an upper tube IGBT device, a lower tube IGBT device, an upper tube anti-parallel diode, a lower tube anti-parallel diode, a DC capacitor, a resistor and a bypass switch; the upper tube anti-parallel diode is connected in parallel to the upper tube IGBT device, the lower tube anti-parallel diode is connected in parallel to the lower tube IGBT device, one end of the upper tube IGBT device is connected to one end of the DC capacitor, the other end of the upper tube IGBT device is connected to one end of the lower tube IGBT device, the other end of the lower tube IGBT device is connected to the other end of the DC capacitor, the resistor is connected in parallel to the DC capacitor, one end of the bypass switch is connected to one end of the lower tube IGBT device, and the other end of the bypass switch is connected to the other end of the lower tube IGBT; wherein the failure characteristics of the upper tube IGBT device and the lower tube IGBT device are short circuit;

[0016] The test submodule in which the IGBT does not have long-term current-carrying capacity comprises an upper tube IGBT device, a lower tube IGBT device, a turn-on thyristor connected in parallel with the lower tube IGBT device, an upper tube anti-parallel diode, a lower tube anti-parallel diode, a DC capacitor, a resistor and a bypass switch; the upper tube anti-parallel diode is connected in parallel to the upper tube IGBT device, the lower tube anti-parallel diode is connected in parallel to the lower tube IGBT device, one end of the upper tube IGBT device is connected to one end of the DC capacitor, the other end of the upper tube IGBT device is connected to one end of the lower tube IGBT device, the other end of the lower tube IGBT device is connected to the other end of the DC capacitor, the turn-on thyristor is connected in parallel to the lower tube IGBT device, the resistor is connected in parallel to the DC capacitor, one end of the bypass switch is connected to one end of the lower tube IGBT device, and the other end of the bypass switch is connected to the other end of the lower tube IGBT device; wherein the failure characteristics of the upper tube IGBT device and the lower tube IGBT device are open circuit.

[0017] Preferably, the upper and lower IGBT through-destructive tests are performed on the test submodule with long-term current-carrying capacity of the IGBT and the test submodule without long-term current-carrying capacity of the IGBT respectively, including:

[0018] The desaturation protection functions of the test submodules of the IGBT with long-term current-carrying capacity and the test submodules of the IGBT without long-term current-carrying capacity are respectively shielded, and charged to a first predetermined test voltage;

[0019] Actively triggering and turning on the upper IGBT device and the lower IGBT device in the test submodule with the IGBT having long-term current-carrying capability and the test submodule with the IGBT not having long-term current-carrying capability, so as to form an upper and lower tube direct short-circuit loop;

[0020] The first predetermined test voltage is respectively a latching overvoltage protection setting value of a test submodule of the IGBT with long-term current-carrying capability and a test submodule of the IGBT without long-term current-carrying capability.

[0021] Preferably, a bypass switch mis-closing destructive test is performed on the test submodule of the IGBT with long-term current-carrying capacity, including:

[0022] Increasing the operating voltage of the test submodule with long-term current-carrying capacity of the IGBT, and when the capacitance voltage of the DC capacitor in the test submodule with long-term current-carrying capacity of the IGBT reaches a second predetermined test voltage, issuing a command to close the bypass switch to form a short-circuit loop;

[0023] The second predetermined test voltage is a locked overvoltage protection setting of the test submodule of the IGBT with long-term current-carrying capability.

[0024] Preferably, a bypass switch refusal destructive test is performed on the test submodule of the IGBT with long-term current flow capability, including:

[0025] Shielding or removing the bypass switch in the test submodule of the IGBT with long-term current-carrying capacity to render the bypass switch ineffective;

[0026] Increasing the charging voltage of the test submodule with long-term current-carrying capacity of the IGBT, when the capacitance voltage of the DC capacitor in the test submodule with long-term current-carrying capacity of the IGBT reaches a third predetermined test voltage, so that the upper tube IGBT device and the lower tube IGBT device are over-voltage-broken and present a short-circuit state;

[0027] The third predetermined test voltage is an upper limit value of the active breakdown voltage of the upper IGBT device and the lower IGBT device of the test submodule in which the IGBT has long-term current-carrying capability.

[0028] Preferably, a bypass switch refusal destructive test is performed on the test submodule of the IGBT that does not have long-term current-carrying capacity, including:

[0029] Disconnect the bypass switch closing circuit of the test submodule whose IGBT does not have long-term current-carrying capacity to simulate switch refusal;

[0030] The charging voltage of the test submodule of the IGBT that does not have long-term current-carrying capacity is increased, and when the capacitance voltage of the DC capacitor in the test submodule of the IGBT that has long-term current-carrying capacity reaches a fourth predetermined test voltage, the transition thyristor, the upper IGBT device or the upper anti-parallel diode is over-voltage-broken and presents a short-circuit state;

[0031] The fourth predetermined test voltage is an upper limit value of a breakdown voltage of a thyristor of a test submodule in which the IGBT does not have a long-term current-carrying capability.

[0032] In order to solve the above technical problems, an embodiment of the present invention further provides a destructive test device for a flexible DC converter valve, comprising:

[0033] An IGBT test submodule construction module, used to construct an IGBT test submodule according to the long-term flow capacity of the IGBT device in the flexible DC converter valve submodule; wherein the IGBT test submodule includes a test submodule with an IGBT having a long-term flow capacity and a test submodule with an IGBT not having a long-term flow capacity;

[0034] The upper and lower IGBT direct destructive test modules are used to respectively perform the upper and lower IGBT direct destructive test on the test submodule with long-term current carrying capacity of the IGBT and the test submodule without long-term current carrying capacity of the IGBT;

[0035] A bypass switch mis-closing destructive test module, used to perform a bypass switch mis-closing destructive test on the test submodule of the IGBT with long-term current-carrying capacity;

[0036] A bypass switch refusal to operate destructive test module is used to perform a bypass switch refusal to operate destructive test on the test submodule with long-term current-carrying capacity of the IGBT and the test submodule with no long-term current-carrying capacity of the IGBT respectively;

[0037] The test judgment module is used to judge the explosion-proof performance of the flexible DC converter valve according to the test phenomena of the upper and lower IGBT direct-through destructive test, the bypass switch misclosing destructive test and the bypass switch refusal to operate destructive test to obtain the test results.

[0038] To solve the above technical problems, an embodiment of the present invention provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor implements the destructive test method for a flexible DC converter valve as described in any one of the above when executing the computer program.

[0039] In order to solve the above technical problems, an embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the destructive test method for the flexible DC converter valve as described in any one of the above.

[0040] Compared with the prior art, the embodiments of the present invention provide a destructive test method, device, equipment and medium for a flexible DC converter valve. First, according to the long-term flow capacity of the IGBT device in the flexible DC converter valve submodule, an IGBT test submodule is constructed; wherein the IGBT test submodule includes a test submodule with an IGBT having a long-term flow capacity and a test submodule with an IGBT not having a long-term flow capacity; secondly, the upper and lower IGBT direct-through destructive tests are respectively performed on the test submodule with the IGBT having a long-term flow capacity and the test submodule with the IGBT not having a long-term flow capacity, the bypass switch mis-closing destructive test is performed on the test submodule with the IGBT having a long-term flow capacity, and the bypass switch refusal to operate destructive test is respectively performed on the test submodule with the IGBT having a long-term flow capacity and the test submodule with the IGBT not having a long-term flow capacity; finally, the explosion-proof performance of the flexible DC converter valve is judged according to the test phenomena of the above three types of tests to obtain test results. The present invention divides the IGBT test submodules into the IGBT test submodules with long-term current-carrying capacity and the IGBT test submodules without long-term current-carrying capacity, and performs three types of tests, namely, upper and lower IGBT direct-through destructive test, bypass switch misclosing destructive test and bypass switch refusal to operate destructive test. The present invention can simulate the actual working environment of the flexible DC converter valve, better meet the needs of the flexible DC converter valve destructive test, improve the accuracy of the test results, and detect the performance reliability of the flexible DC converter valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solution of the present invention, the drawings used in the implementation mode will be briefly introduced below. Obviously, the drawings described below are only some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 It is a flow chart of a destructive test method of a flexible DC converter valve provided by an embodiment of the present invention;

[0043] Figure 2 It is an electrical schematic diagram of a test submodule of an IGBT with long-term current-carrying capability provided by an embodiment of the present invention;

[0044] Figure 3 It is an electrical schematic diagram of a test submodule of an IGBT provided in an embodiment of the present invention that does not have long-term current-carrying capability;

[0045] Figure 4 is another flow chart of a destructive test method for a flexible DC converter valve provided by an embodiment of the present invention;

[0046] Figure 5It is a schematic diagram of the overall assessment level upper and lower IGBT direct destructive test provided by an embodiment of the present invention;

[0047] Figure 6 This is a schematic diagram of a device assessment level upper and lower IGBT direct destructive test provided by an embodiment of the present invention;

[0048] Figure 7 It is a schematic diagram of a bypass switch misclosing destructive test for overall level assessment provided by an embodiment of the present invention;

[0049] Figure 8 It is a schematic diagram of a bypass switch mis-closing destructive test for a device-level assessment provided by an embodiment of the present invention;

[0050] Fig. 9 It is a schematic diagram of a destructive test of an overall assessment-level bypass switch refusal to operate of a test submodule of an IGBT with long-term current-carrying capacity provided by an embodiment of the present invention;

[0051] Fig.10 It is a schematic diagram of a destructive test of a bypass switch refusal to operate at a device assessment level for a test submodule of an IGBT with long-term current-carrying capacity provided by an embodiment of the present invention;

[0052] Fig.11 It is a schematic diagram of a destructive test of the overall assessment-level bypass switch refusal to operate provided by an embodiment of the present invention for a test submodule of an IGBT that does not have a long-term current-carrying capacity;

[0053] Fig.12 It is a schematic diagram of a device assessment-level bypass switch refusal to operate destructive test for a test submodule of an IGBT without long-term current-carrying capability provided by an embodiment of the present invention;

[0054] Fig.13 It is a structural block diagram of a destructive test device for a flexible DC converter valve provided by an embodiment of the present invention;

[0055] Fig.14 It is a structural block diagram of a terminal device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] See also Figure 1, a flowchart of a destructive test method for a flexible DC converter valve provided in an embodiment of the present invention, the destructive test method for a flexible DC converter valve comprises steps S1 to S5:

[0058] S1. According to the long-term flow capacity of the IGBT device in the flexible DC converter valve submodule, an IGBT test submodule is constructed; wherein the IGBT test submodule includes a test submodule in which the IGBT has a long-term flow capacity and a test submodule in which the IGBT does not have a long-term flow capacity;

[0059] Specifically, the IGBT test submodule with long-term current-carrying capacity includes an upper tube IGBT device, a lower tube IGBT device, an upper tube anti-parallel diode, a lower tube anti-parallel diode, a DC capacitor, a resistor and a bypass switch; the upper tube anti-parallel diode is connected in parallel to the upper tube IGBT device, the lower tube anti-parallel diode is connected in parallel to the lower tube IGBT device, one end of the upper tube IGBT device is connected to one end of the DC capacitor, the other end of the upper tube IGBT device is connected to one end of the lower tube IGBT device, the other end of the lower tube IGBT device is connected to the other end of the DC capacitor, the resistor is connected in parallel to the DC capacitor, one end of the bypass switch is connected to one end of the lower tube IGBT device, and the other end of the bypass switch is connected to the other end of the lower tube IGBT; wherein the failure characteristics of the upper tube IGBT device and the lower tube IGBT device are short circuit;

[0060] The test submodule in which the IGBT does not have long-term current-carrying capacity comprises an upper tube IGBT device, a lower tube IGBT device, a turn-on thyristor connected in parallel with the lower tube IGBT device, an upper tube anti-parallel diode, a lower tube anti-parallel diode, a DC capacitor, a resistor and a bypass switch; the upper tube anti-parallel diode is connected in parallel to the upper tube IGBT device, the lower tube anti-parallel diode is connected in parallel to the lower tube IGBT device, one end of the upper tube IGBT device is connected to one end of the DC capacitor, the other end of the upper tube IGBT device is connected to one end of the lower tube IGBT device, the other end of the lower tube IGBT device is connected to the other end of the DC capacitor, the turn-on thyristor is connected in parallel to the lower tube IGBT device, the resistor is connected in parallel to the DC capacitor, one end of the bypass switch is connected to one end of the lower tube IGBT device, and the other end of the bypass switch is connected to the other end of the lower tube IGBT device; wherein the failure characteristics of the upper tube IGBT device and the lower tube IGBT device are open circuit.

[0061] For example, see Figure 2 , Figure 2 : is an electrical schematic diagram of a test submodule of an IGBT with long-term current-carrying capability provided by an embodiment of the present invention, such as Figure 2 As shown, VT1 and VT2 are upper and lower IGBT devices respectively; D1 and D2 are upper and lower anti-parallel diodes respectively; C is a DC capacitor for the flexible DC converter valve submodule; R is a voltage-equalizing resistor; and K is a bypass switch. The upper anti-parallel diode D1 is connected in parallel to the upper IGBT device VT1, the lower anti-parallel diode D2 is connected in parallel to the lower IGBT device VT2, one end of the upper IGBT device VT1 is connected to one end of the DC capacitor C, the other end of the upper IGBT device VT1 is connected to one end of the lower IGBT device VT2, the other end of the lower IGBT device VT2 is connected to the other end of the DC capacitor C, the resistor R is connected in parallel to the DC capacitor C, one end of the bypass switch K is connected to one end of the lower IGBT device VT2, and the other end of the bypass switch K is connected to the other end of the lower IGBT device VT2.

[0062] See also Figure 3 , Figure 3 It is an electrical schematic diagram of a test submodule of an IGBT without long-term current-carrying capability provided in an embodiment of the present invention. Compared with the test submodule of an IGBT with long-term current-carrying capability, the failure characteristic of the configured power device IGBT is short circuit, and the circuit is provided with a turning thyristor T in parallel with the lower tube IGBT.

[0063] S2, respectively performing upper and lower IGBT direct destructive tests on the test submodule with long-term current-carrying capacity of the IGBT and the test submodule without long-term current-carrying capacity of the IGBT;

[0064] In one embodiment, the performing upper and lower IGBT through-destructive tests on the test submodule with long-term current-carrying capability of the IGBT and the test submodule without long-term current-carrying capability of the IGBT respectively includes:

[0065] The desaturation protection functions of the test submodules of the IGBT with long-term current-carrying capacity and the test submodules of the IGBT without long-term current-carrying capacity are respectively shielded, and charged to a first predetermined test voltage;

[0066] Actively triggering and turning on the upper IGBT device and the lower IGBT device in the test submodule with the IGBT having long-term current-carrying capability and the test submodule with the IGBT not having long-term current-carrying capability, so as to form an upper and lower tube direct short-circuit loop;

[0067] The first predetermined test voltage is respectively a latching overvoltage protection setting value of a test submodule of the IGBT with long-term current-carrying capability and a test submodule of the IGBT without long-term current-carrying capability.

[0068] Preferably, the upper and lower IGBT through-destructive test includes an overall assessment level destructive test and a device assessment level destructive test.

[0069] In one embodiment, the IGBT test submodule is subjected to an overall assessment level upper and lower IGBT through-destructive test, including:

[0070] Desaturate the IGBT test submodule to drive the protection shield and charge it to a predetermined voltage;

[0071] Actively trigger and turn on the lower IGBT device, and establish current in the lower IGBT device through the inductor loop;

[0072] The upper IGBT device is triggered after a predetermined time, and when the upper and lower IGBT devices are turned on at the same time, a direct short-circuit loop is formed.

[0073] In one embodiment, the IGBT test submodule is subjected to a device assessment level upper and lower IGBT direct destructive test, including:

[0074] A metal block is used to replace the upper IGBT device in the IGBT test submodule to construct a first equivalent test circuit;

[0075] The capacitor in the first equivalent test circuit is charged to reach a preset voltage;

[0076] The lower IGBT device is actively triggered to turn on, and the upper metal block and the lower IGBT device form a direct short-circuit loop.

[0077] It should be noted that, since the upper and lower tube direct short-circuit loops need to test the IGBT test sub-module with long-term current-carrying capability and the IGBT test sub-module without long-term current-carrying capability respectively, the "IGBT test sub-module" mentioned above includes two test sub-modules, namely, the IGBT test sub-module with long-term current-carrying capability and the IGBT test sub-module without long-term current-carrying capability, for simplified expression.

[0078] S3, performing a bypass switch mis-closing destructive test on the test submodule of the IGBT with long-term current-carrying capacity;

[0079] In one embodiment, a bypass switch mis-closing destructive test is performed on the IGBT test submodule with long-term current-carrying capability, including:

[0080] Increasing the operating voltage of the test submodule with long-term current-carrying capacity of the IGBT, and when the capacitance voltage of the DC capacitor in the test submodule with long-term current-carrying capacity of the IGBT reaches a second predetermined test voltage, issuing a command to close the bypass switch to form a short-circuit loop;

[0081] The second predetermined test voltage is a locked overvoltage protection setting of the test submodule of the IGBT with long-term current-carrying capability.

[0082] Preferably, the bypass switch misclosing destructive test includes an overall assessment level destructive test and a device assessment level destructive test.

[0083] In one embodiment, the test submodule of the IGBT with long-term current-carrying capacity is used to perform an overall assessment-level bypass switch mis-closing destructive test, including:

[0084] Improving the operating voltage of the test submodule of the IGBT with long-term current-carrying capacity;

[0085] When the charging voltage of the test submodule with long-term current-carrying capacity of the IGBT is not lower than the locking voltage, when the upper IGBT device is on, a command is issued to close the bypass switch, and the upper IGBT device and the bypass switch form a short-circuit loop.

[0086] In one embodiment, a destructive test of a bypass switch mis-closing at a device assessment level is performed using the test submodule of the IGBT with long-term current-carrying capability, including:

[0087] A failed IGBT device or a metal block is used to replace the upper IGBT device in the test submodule with the IGBT having long-term current-carrying capacity, to construct a second equivalent test circuit;

[0088] Increasing the operating voltage of the second equivalent test circuit;

[0089] When the charging voltage of the second equivalent test circuit is not lower than the locking voltage, when the upper tube IGBT device is in the on state, a command is issued to close the bypass switch, and the upper tube failed IGBT device or metal block and the bypass switch form a short circuit.

[0090] S4, respectively performing a bypass switch refusal to operate destructive test on the test submodule with long-term current-carrying capacity of the IGBT and the test submodule with no long-term current-carrying capacity of the IGBT;

[0091] In one embodiment, a bypass switch refusal destructive test is performed on the IGBT test submodule with long-term current flow capability, including:

[0092] Shielding or removing the bypass switch in the test submodule of the IGBT with long-term current-carrying capacity to render the bypass switch ineffective;

[0093] Increasing the charging voltage of the test submodule with long-term current-carrying capacity of the IGBT, when the capacitance voltage of the DC capacitor in the test submodule with long-term current-carrying capacity of the IGBT reaches a third predetermined test voltage, so that the upper tube IGBT device and the lower tube IGBT device are over-voltage-broken and present a short-circuit state;

[0094] The third predetermined test voltage is an upper limit value of the active breakdown voltage of the upper IGBT device and the lower IGBT device of the test submodule in which the IGBT has long-term current-carrying capability.

[0095] In one embodiment, a bypass switch refusal destructive test is performed on the test submodule of the IGBT that does not have long-term current flow capability, including:

[0096] Disconnect the bypass switch closing circuit of the test submodule whose IGBT does not have long-term current-carrying capacity to simulate switch refusal;

[0097] The charging voltage of the test submodule of the IGBT that does not have long-term current-carrying capacity is increased, and when the capacitance voltage of the DC capacitor in the test submodule of the IGBT that has long-term current-carrying capacity reaches a fourth predetermined test voltage, the transition thyristor, the upper IGBT device or the upper anti-parallel diode is over-voltage-broken and presents a short-circuit state;

[0098] The fourth predetermined test voltage is an upper limit value of a breakdown voltage of a thyristor of a test submodule in which the IGBT does not have a long-term current-carrying capability.

[0099] Preferably, the bypass switch refusal to operate destructive test includes an overall assessment level destructive test and a device assessment level destructive test.

[0100] Specifically, the IGBT test sample submodule is used to perform a bypass switch refusal destructive test, including:

[0101] Conducting an overall assessment-level bypass switch refusal to operate destructive test on the test submodule of the IGBT with long-term current-carrying capacity;

[0102] Conducting a device assessment-level bypass switch refusal to operate destructive test on the test submodule of the IGBT with long-term current-carrying capacity;

[0103] Conducting an overall assessment-level bypass switch refusal to operate destructive test on the test submodule of the IGBT that does not have long-term current-carrying capacity;

[0104] A device assessment-level bypass switch refusal to operate destructive test is performed on the test submodule of the IGBT that does not have long-term current-carrying capacity.

[0105] In one embodiment, the overall assessment-level bypass switch refusal to operate destructive test is performed on the test submodule of the IGBT with long-term current-carrying capability, including:

[0106] Shield or remove the bypass switch of the test submodule of the IGBT with long-term current-carrying capacity, so that the bypass switch fails;

[0107] The power module is continuously pressurized so that the capacitor voltage of the test submodule with long-term current-carrying capacity of the IGBT is charged to a preset voltage until the upper and lower IGBT devices are over-voltage-broken and present a short-circuit state.

[0108] In one embodiment, the device assessment level bypass switch refusal to operate destructive test is performed on the test submodule of the IGBT with long-term current flow capability, including:

[0109] Shield or remove the bypass switch of the test submodule of the IGBT with long-term current-carrying capacity, so that the bypass switch fails;

[0110] An insulating block is used to replace the upper tube IGBT device of the test submodule with the IGBT having long-term current flow capability, so as to construct a third equivalent test circuit;

[0111] The power module is continuously pressurized to charge the capacitor voltage of the third equivalent test circuit to a preset voltage until the upper and lower IGBT devices are over-voltage-broken and present a short-circuit state.

[0112] In one embodiment, the overall assessment-level bypass switch refusal to operate destructive test is performed on the test submodule of the IGBT that does not have long-term current-carrying capacity, including:

[0113] The bypass switch closing circuit of the test submodule whose IGBT does not have long-term current-carrying capacity is disconnected to simulate the switch refusal to operate;

[0114] The power module is continuously pressurized until the turning thyristor, the upper IGBT device or the upper anti-parallel diode is over-voltage-broken, resulting in a short-circuit state.

[0115] In one embodiment, the overall assessment-level bypass switch refusal to operate destructive test is performed on the test submodule of the IGBT that does not have long-term current-carrying capacity, including:

[0116] Shield or remove the bypass switch of the test submodule whose IGBT does not have long-term current-carrying capacity, so that the bypass switch fails;

[0117] An insulating block is used to replace the upper and lower IGBT devices in the test submodule of the IGBT that does not have long-term current-carrying capacity, to construct a fourth equivalent test circuit;

[0118] The power module is continuously pressurized until the turning thyristor and the upper tube anti-parallel diode of the fourth equivalent test circuit are over-voltage-broken and present a short-circuit state.

[0119] S5. Determine the explosion-proof performance of the flexible DC converter valve according to the test phenomenon to obtain test results.

[0120] Specifically, determine whether the IGBT test submodule with long-term current-carrying capacity / IGBT test submodule without long-term current-carrying capacity has exploded, whether there is water leakage in the cooling system after the explosion, whether there are objects flying, and whether the busbar components inside the IGBT test submodule are deformed;

[0121] If so, it is determined that the destructive test of the flexible DC converter valve is unsuccessful.

[0122] As an improvement of the above solution, the above-mentioned destructive test method for the flexible DC converter valve further includes:

[0123] A 168-hour long-term current conduction test is performed on the test submodule with long-term current conduction capability of the IGBT and the test submodule with no long-term current conduction capability according to the maximum operating current values ​​of the test submodule with long-term current conduction capability of the IGBT and the test submodule with no long-term current conduction capability, respectively.

[0124] It is worth noting that, in the embodiment of the present invention, the upper and lower IGBT direct destructive test, the bypass switch mis-closing destructive test and the bypass switch refusal destructive test all include an overall assessment level destructive test and a device assessment level destructive test. Among them, the upper and lower IGBT direct destructive test can simulate the extreme situation of the upper and lower IGBTs being turned on at the same time, and verify whether the system can work normally or safely enter the protection state in this case; the bypass switch mis-closing destructive test can simulate the extreme situation of the bypass switch mis-closing, and verify whether the system can detect the mis-closing in time and take protective measures in this case; the bypass switch refusal destructive test can simulate the extreme situation of the bypass switch refusal to verify whether the system can detect the refusal to move in time and take protective measures in this case. Among them, the overall assessment level destructive test is intended to verify the overall reliability of the flexible DC converter valve under extreme conditions, and the device assessment level destructive test is intended to verify the reliability of key components in the system. By conducting overall assessment level and device assessment level destructive tests, the reliability of the flexible DC converter valve and key components can be comprehensively evaluated to ensure that the flexible DC converter valve can operate safely and reliably in actual applications.

[0125] It should be noted that the overall assessment level destructive test is conducted on the complete IGBT test submodule; the device assessment level destructive test uses insulating pads or metal blocks or failed IGBT devices to replace the IGBT devices in the IGBT test submodule, and constructs an equivalent test circuit for testing. Among them, the device assessment level destructive test is aimed at assessing the most demanding fault impact current of various devices, and uses insulating pads, metal blocks, failed IGBT devices and other objects to design equivalent test circuits.

[0126] In order to make the technical scheme of the present invention more clearly understood by those skilled in the art, the test method provided by the present invention is further described below in conjunction with specific test implementation steps.

[0127] The embodiment of the present invention aims at the problem that the submodules of the ultra-high voltage flexible direct current converter are over-voltage due to partial faults in the converter station, which causes the submodules to bypass on a large scale. A destructive test method for flexible direct current converter valves is proposed, especially for ultra-high voltage flexible direct current converter valves, to verify the explosion-proof performance of the converter valve submodules. The following is a detailed description of the test scheme.

[0128] Reference Figure 4 , is a destructive test flow chart of the flexible DC converter valve provided in an embodiment of the present invention. In specific implementation, the flexible DC converter valve is 5kA class. During the test, the DC capacitor is discharged through the short-circuit loop, and the stored energy is released instantly through the power device and the connecting busbar, which may cause the power device shell to rupture due to electrothermal stress, objects to splash, the busbar to break due to electric force shedding, water pipes to leak due to airflow and splashing impact, and the power device that fails after the explosion does not have normal flow capacity. After the test, the explosion-proof performance of the converter valve submodule can be evaluated in detail according to the above standards. If the above situation exists, the test is judged to be unsuccessful. Figure 4 As shown, the test method includes three destructive tests: upper and lower IGBT direct-on, bypass switch mis-closing, and bypass switch refusal to operate.

[0129] 1. Upper and lower IGBT direct destructive test:

[0130] 1) Conduct a destructive test of the upper and lower IGBTs for overall assessment. The test principle diagram is as follows: Figure 5 As shown:

[0131] Step 1: Desaturate the test submodule and drive the protection shield, charge the test submodule to a predetermined voltage, actively trigger the lower tube IGBT-VT2 to turn on, and establish current in the lower tube IGBT-VT2 through the inductor loop;

[0132] Step 2: Then the upper IGBT is triggered, and the upper and lower IGBTs are turned on at the same time, forming a direct short-circuit loop. At this time, the capacitor C is discharged, and the short-circuit large current passes through the upper IGBT-VT1 and the lower IGBT-VT2 in turn. The short-circuit energy release may cause the upper and lower power devices to explode;

[0133] Step 3: After the test, a detailed analysis is conducted on the results of the upper and lower IGBT direct destructive test based on whether the module exploded, whether there was water leakage in the cooling system after the explosion, whether there were objects splashing, deformation of components such as the busbar inside the test submodule, and a 168-hour current-carrying test of the failed power device IGBT-VT2 of the test submodule with long-term current-carrying capacity at the maximum operating current of the module.

[0134] 2) Conduct a device-level destructive test of the upper and lower IGBTs. The test principle diagram is as follows: Figure 6 As shown:

[0135] Step 1: Replace the upper IGBT device in the test submodule with a metal block;

[0136] Step 2: Use a DC power supply to charge the submodule capacitor C and reach a preset voltage;

[0137] Step 3: By actively triggering and turning on the lower tube IGBT-VT2 device, the upper tube metal block and the lower tube IGBT-VT2 form a direct short-circuit loop. At this time, the capacitor C is discharged, and the short-circuit large current passes through the upper tube metal block and the lower tube IGBT-VT2 in turn. The short-circuit energy release may cause the IGBT-VT2 to explode;

[0138] Step 4: After the test, a detailed analysis is conducted based on whether the module exploded, whether there was water leakage in the cooling system after the explosion, whether there were any objects splashing, deformation of components such as the busbar inside the submodule, and the results of the direct destructive test of the upper and lower tubes under the 168-hour current-through test of the failed power device IGBT-VT2 at the maximum operating current of the module.

[0139] 2. Destructive test of bypass switch mis-closing:

[0140] 1) Conduct the bypass switch mis-closing destructive test for overall level assessment. The test principle diagram is as follows: Figure 7 As shown:

[0141] Step 1: Configure bypass switch K in the test submodule to increase the operating voltage of a single submodule to the maximum continuous operating load condition;

[0142] Step 2: When the charging voltage of the test submodule is not lower than the blocking voltage of the submodule, when the upper tube IGBT-VT1 of the converter valve is in the on state, a command is issued to close the submodule bypass switch K. The upper tube IGBT-VT1 and the bypass switch K form a short-circuit loop. At this time, the capacitor C is discharged, and the short-circuit large current passes through the upper tube IGBT-VT1 and the bypass switch K in turn. The short-circuit energy release may cause the upper tube IGBT-VT1 to explode;

[0143] Step 3: After the test, a detailed analysis is conducted based on whether the module exploded, whether there was water leakage in the cooling system after the explosion, whether there were any objects splashing, deformation of components such as the busbar inside the submodule, and the destructive test results of the bypass switch misclosing under the maximum operating current of the module for 168 hours of current flow test on the failed power device IGBT-VT1.

[0144] 2) Conduct a bypass switch mis-closing destructive test for device-level assessment. The test schematic is shown in the figure below: Figure 8 As shown:

[0145] Step 1: Replace the upper tube IGBT-VT1 device in the test submodule with a failed IGBT or metal block;

[0146] Step 2: The test submodule is equipped with a bypass switch K to increase the operating voltage of a single submodule to the maximum continuous operating load condition;

[0147] Step 3: When the charging voltage of the test submodule is not lower than the blocking voltage of the submodule, when the upper tube IGBT-VT1 of the converter valve is in the on state, a command is issued to close the submodule bypass switch K. The upper tube failed IGBT and the bypass switch K form a short-circuit loop. At this time, the capacitor C is discharged, and the short-circuit large current passes through the failed IGBT and the bypass switch K in turn. The short-circuit energy release may cause the failed IGBT to explode;

[0148] Step 4: After the test, a detailed analysis is conducted based on whether the module exploded, whether there was water leakage in the cooling system after the explosion, whether there were any objects splashing, deformation of components such as the busbar inside the submodule, and the destructive test results of the bypass switch misclosing under the maximum operating current of the module for 168 hours of current flow test on the failed power device IGBT.

[0149] 3. Destructive test of bypass switch refusal to operate:

[0150] 1) For the IGBT with long-term failure current-carrying capacity, that is, the test submodule without the switching thyristor is tested for overall bypass switch refusal to operate. The test principle diagram is as follows: Fig. 9 As shown:

[0151] Step 1: Shield or remove the bypass switch K to render it ineffective;

[0152] Step 2: Continuously apply pressure to the power module to charge the submodule capacitor voltage to the preset voltage until the upper and lower power devices are over-voltage and breakdown, presenting a short-circuit state. At this time, the capacitor C is discharged, and the short-circuit large current passes through the broken-down IGBT or anti-parallel diode of the upper and lower tubes in turn. The short-circuit energy release may cause the failed power device to explode;

[0153] Step 3: After the test, a detailed analysis is conducted based on whether the module exploded, whether there was water leakage in the cooling system after the explosion, whether there were objects splashing, deformation of components such as the busbar inside the submodule, and the destructive test results of the bypass switch mis-closing during the 168-hour current flow test of the failed power device IGBT at the maximum operating current of the module;

[0154] 2) Carry out device-level bypass switch refusal test on the IGBT with long-term failure current-carrying capacity, i.e., the test submodule without switching thyristor. The test principle diagram is as follows: Fig.10 As shown:

[0155] Step 1: Shield or remove the bypass switch K to make the bypass switch ineffective K;

[0156] Step 2: Replace the upper IGBT-VT1 device of the test submodule with an insulating block;

[0157] Step 3: Continuously pressurize the power module to charge the submodule capacitor voltage to the preset voltage until the upper and lower power devices are over-voltage and breakdown, presenting a short-circuit state. At this time, the capacitor C is discharged, and the short-circuit large current passes through the upper tube anti-parallel diode D1 that is broken down and the lower tube IGBT-VT1 power device that is broken down in turn. The short-circuit energy release may cause the failed power device to explode;

[0158] Step 4: After the test, a detailed analysis is conducted based on whether the module exploded, whether there was water leakage in the cooling system after the explosion, whether there were any objects splashing, the deformation of components such as the busbar inside the submodule, and the destructive test results of the bypass switch misclosing under the maximum operating current of the module for 168 hours of current flow test on the failed power device.

[0159] 3) For the IGBT that does not have long-term failure current-carrying capacity, that is, the test submodule equipped with the turning thyristor, the overall bypass switch refusal test is carried out. The test principle diagram is as follows Fig.11 As shown:

[0160] Step 1: Disconnect the bypass switch K closing circuit of the power module in the test submodule to simulate the switch failure;

[0161] Step 2: Continue to pressurize the power module until the transition thyristor T, upper tube IGBT-VT1 or anti-parallel diode D1 of the test submodule is over-voltage and breaks down, presenting a short-circuit state. At this time, the capacitor C is discharged, and the short-circuit large current passes through the upper tube broken down power device and the transition thyristor T in turn. The short-circuit energy release may cause the failed power device to explode;

[0162] Step 3: After the test, a detailed analysis is conducted based on whether the module exploded, whether there was water leakage in the cooling system after the explosion, whether there were any objects splashing, the deformation of components such as the busbar inside the submodule, and the destructive test results of the bypass switch misclosing under the maximum operating current of the module for 168 hours of current flow test on the failed power device.

[0163] 4) For the IGBT that does not have long-term failure current-carrying capacity, that is, the test submodule equipped with the turning thyristor, the device-level bypass switch refusal test is carried out. The test principle diagram is as follows Fig.12 As shown:

[0164] Step 1: Shield or remove the bypass switch K to render it ineffective;

[0165] Step 2: Replace the upper and lower IGBT devices in the test submodule with insulating blocks;

[0166] Step 3: Continue to pressurize the power module until the test module's turning thyristor T and the upper tube anti-parallel diode D1 are over-voltage and broken down, presenting a short-circuit state. At this time, the capacitor C is discharged, and the short-circuit large current passes through the upper tube anti-parallel diode D1 that is broken down and the turning thyristor T in turn. The short-circuit energy release may cause the failed power device to explode;

[0167] Step 4: After the test, a detailed analysis is conducted based on whether the module exploded, whether there was water leakage in the cooling system after the explosion, whether there were any objects splashing, the deformation of components such as the busbar inside the submodule, and the destructive test results of the bypass switch misclosing under the maximum operating current of the module for 168 hours of current flow test on the failed power device.

[0168] In summary, a destructive test method for a flexible DC converter valve provided by an embodiment of the present invention, firstly, according to the actual operating conditions during the operation of the flexible DC converter valve, the module destructive test is divided into three categories: upper and lower IGBT direct-flow test, bypass switch misclosing test, and bypass switch refusal test; secondly, for the sub-module in which the IGBT does not have long-term current-carrying capacity and is equipped with a turning thyristor, bypass refusal to move and upper and lower IGBT direct-flow tests are carried out; then, for the sub-module in which the IGBT has long-term current-carrying capacity and is not equipped with a turning thyristor, bypass misclosing, bypass refusal to move, and upper and lower IGBT direct-flow tests are carried out; finally, considering more stringent test conditions, all tests are divided into an overall assessment-level destructive test using a complete module and a device assessment-level destructive test using an equivalent test circuit. On the basis of simulating the actual operating conditions of the converter valve, an equivalent test circuit is formed by insulating gaskets, metal blocks, etc., so as to avoid the current sharing phenomenon existing between the IGBT and the anti-parallel diode, and the explosion-proof performance of the device is assessed under the most stringent conditions, thereby improving the validity of the test conclusion and having industrial application value.

[0169] Based on the above method embodiment, the present invention provides a corresponding device embodiment.

[0170] See also Fig.13 , is a structural block diagram of a flexible DC converter valve destructive test device provided by an embodiment of the present invention, the flexible DC converter valve destructive test device comprising:

[0171] An IGBT test submodule construction module 21 is used to construct an IGBT test submodule according to the long-term flow capacity of the IGBT device in the flexible DC converter valve submodule; wherein the IGBT test submodule includes a test submodule with an IGBT having a long-term flow capacity and a test submodule with an IGBT not having a long-term flow capacity;

[0172] The upper and lower IGBT direct destructive test module 22 is used to perform the upper and lower IGBT direct destructive test on the test submodule with long-term current carrying capacity and the test submodule without long-term current carrying capacity;

[0173] The bypass switch mis-closing destructive test module 23 is used to perform a bypass switch mis-closing destructive test on the test submodule of the IGBT with long-term current-carrying capacity;

[0174] The bypass switch refusal to operate destructive test module 24 is used to perform a bypass switch refusal to operate destructive test on the test submodule with long-term current-carrying capacity of the IGBT and the test submodule with no long-term current-carrying capacity of the IGBT respectively;

[0175] The test judgment module 25 is used to judge the explosion-proof performance of the flexible DC converter valve according to the test phenomena of the upper and lower IGBT direct destructive test, the bypass switch misclosing destructive test and the bypass switch refusal to operate destructive test to obtain the test results.

[0176] As an improvement of the above scheme, the flexible DC converter valve destructive testing device also includes a long-term current flow test module, which is used to perform a 168-hour long-term current flow test on the test submodule with long-term current flow capability of the IGBT and the test submodule without long-term current flow capability according to the maximum operating current values ​​of the test submodule with long-term current flow capability of the IGBT and the test submodule without long-term current flow capability, respectively.

[0177] It should be noted that the flexible DC converter valve destructive testing device provided in an embodiment of the present invention is used to execute all process steps of a flexible DC converter valve destructive testing method in the above embodiment. The working principles and beneficial effects of the two correspond one to one, and thus will not be described in detail.

[0178] The embodiment of the present invention also provides a terminal device, such as Fig.14 , which is a structural block diagram of a preferred embodiment of a terminal device provided by the present invention. The terminal device includes a processor 31, a memory 32, and a computer program stored in the memory 32 and configured to be executed by the processor 31. When the processor 31 executes the computer program, the destructive test method of the flexible DC converter valve described in any of the above embodiments is implemented.

[0179] In addition, an embodiment of the present invention further provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the destructive testing method for the flexible DC converter valve as described in any of the above embodiments.

[0180] When the processor 31 executes the computer program, the steps in the above-mentioned flexible DC converter valve destructive test method embodiment are implemented, for example: Figure 1 Alternatively, when the processor 31 executes the computer program, the functions of each module in the above-mentioned flexible DC converter valve destructive test device are realized, for example Fig.13 The functions of each module of the flexible DC converter valve destructive test device are shown.

[0181] Preferably, the computer program can be divided into one or more modules / units, which are stored in the memory 32 and executed by the processor 31 to implement the present invention. The one or more modules / units can be a series of computer program instruction segments that can implement specific functions, and the instruction segments are used to describe the execution process of the computer program in the terminal device.

[0182] The processor 31 can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor, or the processor 31 can be any conventional processor. The processor 31 is the control center of the terminal device, and various parts of the terminal device are connected using various interfaces and lines.

[0183] The memory 32 mainly includes a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function, etc., and the data storage area can store related data, etc. In addition, the memory 32 can be a high-speed random access memory, or a non-volatile memory, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, and a flash card (Flash Card), etc., or the memory 32 can also be other volatile solid-state storage devices.

[0184] It should be noted that the above terminal device may include, but is not limited to, a processor and a memory. Those skilled in the art will understand that Fig.14 The structural block diagram shown is only a structural example of the above-mentioned terminal device and does not constitute a structural limitation of the above-mentioned terminal device. The above-mentioned terminal device may include more or fewer components than shown in the figure, or combine certain components, or different components.

[0185] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A destructive test method for a flexible DC converter valve, characterized in that: include: According to the long-term flow capacity of the IGBT device in the flexible DC converter valve submodule, an IGBT test submodule is constructed; wherein the IGBT test submodule includes a test submodule in which the IGBT has a long-term flow capacity and a test submodule in which the IGBT does not have a long-term flow capacity; Performing upper and lower IGBT direct destructive tests on the test submodule with long-term current-carrying capacity of the IGBT and the test submodule without long-term current-carrying capacity of the IGBT respectively; Conducting a bypass switch mis-closing destructive test on the test submodule of the IGBT with long-term current-carrying capacity; Conducting a bypass switch refusal to operate destructive test on the test submodule of the IGBT with long-term current-carrying capacity and the test submodule of the IGBT without long-term current-carrying capacity respectively; The explosion-proof performance of the flexible DC converter valve is judged based on the test phenomena of the upper and lower IGBT direct-through destructive test, the bypass switch misclosing destructive test and the bypass switch refusal to operate destructive test to obtain the test results.

2. The destructive test method for a flexible DC converter valve according to claim 1, characterized in that: The upper and lower IGBT straight-through destructive test, bypass switch misclosing destructive test and bypass switch refusal to operate destructive test all include overall assessment level destructive test and device assessment level destructive test.

3. The destructive test method for a flexible DC converter valve according to claim 2, characterized in that: The overall assessment level destructive test is conducted using a complete IGBT test submodule with long-term current-carrying capability / an IGBT test submodule without long-term current-carrying capability; The device assessment level destructive test uses insulating gaskets or metal blocks or failed IGBT devices to replace the IGBT devices in the test submodule with long-term current-carrying capacity / IGBT test submodule without long-term current-carrying capacity to construct an equivalent test circuit for testing.

4. The destructive test method for a flexible DC converter valve according to claim 1, characterized in that: Also includes: A 168-hour long-term current conduction test is performed on the test submodule with long-term current conduction capability of the IGBT and the test submodule with no long-term current conduction capability according to the maximum operating current values ​​of the test submodule with long-term current conduction capability of the IGBT and the test submodule with no long-term current conduction capability, respectively.

5. The destructive test method for a flexible DC converter valve according to claim 1, characterized in that: The IGBT test submodule with long-term current-carrying capacity includes an upper tube IGBT device, a lower tube IGBT device, an upper tube anti-parallel diode, a lower tube anti-parallel diode, a DC capacitor, a resistor and a bypass switch; the upper tube anti-parallel diode is connected in parallel to the upper tube IGBT device, the lower tube anti-parallel diode is connected in parallel to the lower tube IGBT device, one end of the upper tube IGBT device is connected to one end of the DC capacitor, the other end of the upper tube IGBT device is connected to one end of the lower tube IGBT device, the other end of the lower tube IGBT device is connected to the other end of the DC capacitor, the resistor is connected in parallel to the DC capacitor, one end of the bypass switch is connected to one end of the lower tube IGBT device, and the other end of the bypass switch is connected to the other end of the lower tube IGBT; wherein the failure characteristics of the upper tube IGBT device and the lower tube IGBT device are short circuit; The test submodule in which the IGBT does not have long-term current-carrying capacity comprises an upper tube IGBT device, a lower tube IGBT device, a turn-on thyristor connected in parallel with the lower tube IGBT device, an upper tube anti-parallel diode, a lower tube anti-parallel diode, a DC capacitor, a resistor and a bypass switch; the upper tube anti-parallel diode is connected in parallel to the upper tube IGBT device, the lower tube anti-parallel diode is connected in parallel to the lower tube IGBT device, one end of the upper tube IGBT device is connected to one end of the DC capacitor, the other end of the upper tube IGBT device is connected to one end of the lower tube IGBT device, the other end of the lower tube IGBT device is connected to the other end of the DC capacitor, the turn-on thyristor is connected in parallel to the lower tube IGBT device, the resistor is connected in parallel to the DC capacitor, one end of the bypass switch is connected to one end of the lower tube IGBT device, and the other end of the bypass switch is connected to the other end of the lower tube IGBT device; wherein the failure characteristics of the upper tube IGBT device and the lower tube IGBT device are open circuit.

6. The destructive test method for a flexible DC converter valve according to claim 5, characterized in that: The upper and lower IGBT direct destructive tests are respectively performed on the test submodule with long-term current-carrying capacity of the IGBT and the test submodule without long-term current-carrying capacity of the IGBT, including: The desaturation protection functions of the test submodules of the IGBT with long-term current-carrying capacity and the test submodules of the IGBT without long-term current-carrying capacity are respectively shielded, and charged to a first predetermined test voltage; Actively triggering and turning on the upper IGBT device and the lower IGBT device in the test submodule with the IGBT having long-term current-carrying capability and the test submodule with the IGBT not having long-term current-carrying capability, so as to form an upper and lower tube direct short-circuit loop; The first predetermined test voltage is respectively a latching overvoltage protection setting value of a test submodule of the IGBT with long-term current-carrying capability and a test submodule of the IGBT without long-term current-carrying capability.

7. The destructive test method for a flexible DC converter valve according to claim 5, characterized in that: The bypass switch mis-closing destructive test is performed on the test submodule of the IGBT with long-term current-carrying capacity, including: Increasing the operating voltage of the test submodule with long-term current-carrying capacity of the IGBT, and when the capacitance voltage of the DC capacitor in the test submodule with long-term current-carrying capacity of the IGBT reaches a second predetermined test voltage, issuing a command to close the bypass switch to form a short-circuit loop; The second predetermined test voltage is a locked overvoltage protection setting of the test submodule of the IGBT with long-term current-carrying capability.

8. The destructive test method for a flexible DC converter valve according to claim 5, characterized in that: The bypass switch refusal destructive test is carried out on the test submodule of the IGBT with long-term current carrying capacity, including: Shielding or removing the bypass switch in the test submodule of the IGBT with long-term current-carrying capacity to render the bypass switch ineffective; Increasing the charging voltage of the test submodule with long-term current-carrying capacity of the IGBT, when the capacitance voltage of the DC capacitor in the test submodule with long-term current-carrying capacity of the IGBT reaches a third predetermined test voltage, so that the upper tube IGBT device and the lower tube IGBT device are over-voltage-broken and present a short-circuit state; The third predetermined test voltage is an upper limit value of the active breakdown voltage of the upper IGBT device and the lower IGBT device of the test submodule in which the IGBT has long-term current-carrying capability.

9. The destructive test method for a flexible DC converter valve according to claim 5, characterized in that: The bypass switch refusal destructive test is carried out on the test submodule of the IGBT that does not have long-term current-carrying capacity, including: Disconnect the bypass switch closing circuit of the test submodule whose IGBT does not have long-term current-carrying capacity to simulate switch refusal; The charging voltage of the test submodule of the IGBT that does not have long-term current-carrying capacity is increased, and when the capacitance voltage of the DC capacitor in the test submodule of the IGBT that has long-term current-carrying capacity reaches a fourth predetermined test voltage, the transition thyristor, the upper IGBT device or the upper anti-parallel diode is over-voltage-broken and presents a short-circuit state; The fourth predetermined test voltage is an upper limit value of a breakdown voltage of a thyristor of a test submodule in which the IGBT does not have a long-term current-carrying capability.

10. A destructive test device for a flexible DC converter valve, characterized in that: include: An IGBT test submodule construction module, used to construct an IGBT test submodule according to the long-term flow capacity of the IGBT device in the flexible DC converter valve submodule; wherein the IGBT test submodule includes a test submodule with an IGBT having a long-term flow capacity and a test submodule with an IGBT not having a long-term flow capacity; The upper and lower IGBT direct destructive test modules are used to respectively perform the upper and lower IGBT direct destructive test on the test submodule with long-term current carrying capacity of the IGBT and the test submodule without long-term current carrying capacity of the IGBT; A bypass switch mis-closing destructive test module, used to perform a bypass switch mis-closing destructive test on the test submodule of the IGBT with long-term current-carrying capacity; A bypass switch refusal to operate destructive test module is used to perform a bypass switch refusal to operate destructive test on the test submodule with long-term current-carrying capacity of the IGBT and the test submodule with no long-term current-carrying capacity of the IGBT respectively; The test judgment module is used to judge the explosion-proof performance of the flexible DC converter valve according to the test phenomena of the upper and lower IGBT direct-through destructive test, the bypass switch misclosing destructive test and the bypass switch refusal to operate destructive test to obtain the test results.

11. A terminal device, characterized in that: The method comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, the destructive test method for a flexible DC converter valve according to any one of claims 1 to 9 is implemented.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute the destructive testing method for the flexible DC converter valve according to any one of claims 1 to 9.

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