A method and device for identifying fault types in a converter valve power module

Abstract

This invention relates to the field of DC converter valve technology, and particularly to a method and apparatus for identifying fault types in converter valve power modules. The method includes: acquiring a first target parameter, a second target parameter, a third target parameter, a bypass switch status, a bypass switch on-command issuance status, and a target IGBT device on-command issuance status; and identifying the fault type based on a comparison of the first target parameter with a preset first parameter threshold, a comparison of the second target parameter with a preset second parameter threshold, the bypass switch status and the bypass switch on-command issuance status, a comparison of the third target parameter with a preset third parameter threshold, the target IGBT device on-command issuance status, and a comparison of the third target parameter with a preset fourth parameter threshold and the target IGBT device on-command issuance status. Existing fault identification methods suffer from the technical problems of being time-consuming and inefficient.

Description

Technical Field

[0001] This invention relates to the field of DC converter valve technology, and in particular to a method and apparatus for identifying fault types in converter valve power modules. Background Technology

[0002] A converter valve power module (or simply power module) is a device used for power conversion, which can convert alternating current (AC) to direct current (DC) or vice versa. In a flexible DC transmission system, the control system can send control signals to the gate drive circuit of the converter valve power module according to the power conversion requirements. The IGBT devices inside the converter valve power module then turn on and off in a certain sequence and time interval to achieve power conversion.

[0003] During operation, once the converter valve power module in the flexible DC transmission system is unlocked, it will be in an "engaged" state. If a DC capacitor shoot-through fault occurs in this state, the power module control board in the system can only identify the DC capacitor shoot-through fault and send an "IGBT shoot-through fault" message to the upper-level valve control system. It cannot accurately identify which specific component within the power module is causing the shoot-through fault. Current technology requires waiting until the transmission project is shut down, then removing the faulty power module from the valve tower and returning it to the manufacturer for disassembly and analysis to determine which internal component caused the shoot-through fault. However, this approach results in excessively long time required to determine the cause of the fault, leading to low efficiency in troubleshooting. Summary of the Invention

[0004] This invention provides a method and apparatus for identifying fault types in a converter valve power module, which solves the technical problems of long time consumption and low efficiency in existing fault identification methods.

[0005] This invention provides a method for identifying fault types in a converter valve power module. The power module includes a bypass thyristor, a bypass switch, and an IGBT assembly; the IGBT assembly includes a target IGBT device; when the power module is in operation and a shoot-through fault exists, the method includes:

[0006] Acquire the first target parameter, the second target parameter, the third target parameter, the bypass switch status, the bypass switch turn-on command issuance status, and the target IGBT device turn-on command issuance status;

[0007] Based on the comparison result between the first target parameter and the preset first parameter threshold, it is determined whether the bypass thyristor has a low-voltage breakdown fault. If so, the fault type is determined to be low-voltage breakdown of the bypass thyristor.

[0008] Based on the comparison result between the second target parameter and the preset second parameter threshold, the status of the bypass switch and the issuance status of the bypass switch conduction command, it is determined whether there is a gap discharge in the bypass switch. If so, the fault type is determined to be a bypass switch gap discharge.

[0009] Based on the comparison result between the third target parameter and the preset third parameter threshold, and the issuance status of the target IGBT device turn-on command, it is determined whether the target IGBT device has a false triggering fault. If so, the fault type is determined to be IGBT device false triggering.

[0010] Based on the comparison result between the third target parameter and the preset fourth parameter threshold, and the issuance status of the target IGBT device turn-on command, it is determined whether the target IGBT device has a short-circuit failure fault. If so, the fault type is determined to be an IGBT device short-circuit failure fault.

[0011] Optionally, the first target parameter includes the current and first duration of the bypass thyristor, the first inter-electrode voltage and the second duration of the target IGBT device; the first parameter threshold includes a first voltage threshold, a first current threshold, a first time threshold and a second time threshold;

[0012] The step of determining whether the bypass thyristor has experienced a low-voltage breakdown fault based on the comparison result between the first target parameter and the preset first parameter threshold includes:

[0013] When the first inter-electrode voltage is less than the first voltage threshold and the second duration exceeds the first time threshold, and the current of the bypass thyristor is greater than the first current threshold and the first duration exceeds the second time threshold, it is determined that the bypass thyristor has a low-voltage breakdown fault.

[0014] Optionally, the second target parameter includes the first inter-electrode voltage and the second duration of the target IGBT device, the current of the bypass switch, and the third duration; the second parameter threshold includes the first voltage threshold, the first time threshold, the second current threshold, and the third time threshold.

[0015] The step of determining whether there is gap discharge in the bypass switch based on the comparison result between the second target parameter and the preset second parameter threshold, the status of the bypass switch, and the issuance status of the bypass switch conduction command includes:

[0016] When the first inter-electrode voltage is less than the first voltage threshold and the first duration exceeds the first time threshold, and the current of the bypass switch is greater than the second current threshold and the third duration exceeds the third time threshold, and the bypass switch conduction command is not issued, and the bypass switch is in the open state, it is determined that there is a gap discharge in the bypass switch.

[0017] Optionally, the third target parameter includes: the first inter-electrode voltage and the second duration of the target IGBT device, the current and the fourth duration of the target IGBT device, and the second inter-electrode voltage and the fifth duration of the target IGBT device; the third parameter threshold includes: the first voltage threshold, the first time threshold, the third current threshold, the fourth time threshold, the target on-voltage, and the fifth time threshold;

[0018] The step of determining whether the target IGBT device has a false triggering fault based on the comparison result between the third target parameter and the preset third parameter threshold, and the issuance status of the target IGBT device turn-on command, includes:

[0019] When the first inter-electrode voltage is less than the first voltage threshold and the first duration exceeds the first time threshold, and the current of the target IGBT device is greater than the third current threshold and the fourth duration exceeds the fourth time threshold, and the target IGBT device turn-on command is not issued, and the second inter-electrode voltage is greater than the target turn-on voltage and the fifth duration is greater than the fifth time threshold, it is determined that the target IGBT device has a false triggering fault.

[0020] Optionally, the fourth parameter threshold includes the first voltage threshold, the first time threshold, the third current threshold, the fourth time threshold, the target on-state voltage, and the sixth time threshold;

[0021] The step of determining whether the target IGBT device has a short-circuit failure based on the comparison result of the third target parameter and the preset fourth parameter threshold, and the issuance status of the target IGBT device turn-on command, includes:

[0022] When the first inter-electrode voltage is less than the first voltage threshold and the first duration exceeds the first time threshold, and the current of the target IGBT device is greater than the third current threshold and the fourth duration exceeds the fourth time threshold, and the target IGBT device turn-on command is not issued, and the second inter-electrode voltage is less than the target turn-on voltage and the fifth duration is greater than the fifth time threshold, it is determined that the target IGBT device has a short-circuit failure fault.

[0023] Optionally, when the power module is a full-bridge power module, the first target parameter includes the current of the bypass thyristor and a first duration, a first inter-electrode voltage difference, a second inter-electrode voltage difference, and a sixth duration; the first parameter threshold includes a first voltage threshold, a first current threshold, a first time threshold, and a second time threshold.

[0024] The step of determining whether the bypass thyristor has experienced a low-voltage breakdown fault based on the comparison result between the first target parameter and the preset first parameter threshold includes:

[0025] When the voltage difference between the first and second electrodes is less than the first voltage threshold and the sixth duration exceeds the first time threshold, and the current of the bypass thyristor is greater than the first current threshold and the first duration exceeds the second time threshold, it is determined that the bypass thyristor has a low-voltage breakdown fault.

[0026] Optionally, the second target parameter includes the current of the bypass switch and the third duration, the first inter-electrode voltage difference, the second inter-electrode voltage difference, and the sixth duration; the second parameter threshold includes the first voltage threshold, the first time threshold, the second current threshold, and the third time threshold.

[0027] The step of determining whether there is gap discharge in the bypass switch based on the comparison result between the second target parameter and the preset second parameter threshold, the status of the bypass switch, and the issuance status of the bypass switch conduction command includes:

[0028] When the voltage difference between the first and second electrodes is less than the first voltage threshold, the sixth duration exceeds the first time threshold, the current of the bypass switch is greater than the second current threshold, the third duration exceeds the third time threshold, the bypass switch conduction command is not issued, and the bypass switch is in the open state, it is determined that there is a gap discharge in the bypass switch.

[0029] Optionally, when the power module is a half-bridge power module, the target IGBT device is an IGBT device that is in the off state in the half-bridge power module that is in the on state.

[0030] Optionally, when the power module is a full-bridge power module, the target IGBT device includes either one of the two IGBT devices in the off state within the full-bridge power module that is in the on state.

[0031] In another aspect, the present invention provides a fault type identification device for a converter valve power module, the device including a processor and a memory;

[0032] The memory is used to store program code and transmit the program code to the processor;

[0033] The processor is configured to execute the method described above according to instructions in the program code.

[0034] As can be seen from the above technical solutions, the present invention has the following advantages:

[0035] This invention provides a method for identifying fault types in a converter valve power module. The power module includes a bypass thyristor, a bypass switch, and an IGBT assembly. The IGBT assembly includes a target IGBT device. When the power module is in the active state and a shoot-through fault exists, the method includes: acquiring a first target parameter, a second target parameter, a third target parameter, a bypass switch state, a bypass switch on-state command issuance state, and a target IGBT device on-state command issuance state; determining whether the bypass thyristor has experienced a low-voltage breakdown fault based on a comparison between the first target parameter and a preset first parameter threshold; if so, determining the fault type as bypass thyristor low-voltage breakdown; and further determining the fault type based on a comparison between the second target parameter and a preset second parameter threshold. Based on the results, the status of the bypass switch, and the issuance status of the bypass switch turn-on command, it is determined whether there is a gap discharge in the bypass switch. If so, the fault type is determined to be a bypass switch gap discharge. Based on the comparison result of the third target parameter and the preset third parameter threshold, and the issuance status of the target IGBT device turn-on command, it is determined whether there is a false triggering fault in the target IGBT device. If so, the fault type is determined to be an IGBT device false triggering. Based on the comparison result of the third target parameter and the preset fourth parameter threshold, and the issuance status of the target IGBT device turn-on command, it is determined whether there is a short circuit failure fault in the target IGBT device. If so, the fault type is determined to be an IGBT device short circuit failure fault.

[0036] In this invention, by acquiring a first target parameter, a second target parameter, a third target parameter, a bypass switch state, a bypass switch on-state command issuance state, and a target IGBT device on-state command issuance state, and based on the comparison result of the first target parameter and a preset first parameter threshold, it is determined whether the bypass thyristor has experienced a low-voltage breakdown fault. If so, the fault type is determined to be bypass thyristor low-voltage breakdown, thus achieving the identification of bypass thyristor low-voltage breakdown. Furthermore, based on the comparison result of the second target parameter and a preset second parameter threshold, the bypass switch state, and the bypass switch on-state command issuance state, it is determined whether the bypass switch has a gap discharge. If so, the fault type is determined to be bypass switch gap discharge. This invention enables the identification of faults such as discharge in the bypass switch gap. Based on the comparison between the third target parameter and a preset third parameter threshold, and the issuance status of the target IGBT device's turn-on command, it determines whether the target IGBT device has a false triggering fault. If so, the fault type is determined to be IGBT device false triggering, thus achieving the identification of IGBT device false triggering faults. Furthermore, based on the comparison between the third target parameter and a preset fourth parameter threshold, and the issuance status of the target IGBT device's turn-on command, it determines whether the target IGBT device has a short-circuit failure fault. If so, the fault type is determined to be IGBT device short-circuit failure, thus achieving the identification of IGBT device short-circuit failure faults. As can be seen from the above, when the power module is in the activated state and a shoot-through fault exists, the identification method provided by this invention can quickly and accurately identify the faulty component and fault type without disassembling the power module. This solves the technical problems of long time consumption and low efficiency in existing fault identification methods, achieving the technical effect of reducing fault troubleshooting time and improving fault troubleshooting efficiency. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 Here is a flowchart of a method for identifying fault types in a converter valve power module according to Embodiment 1 of the present invention;

[0039] Figure 2 This is a schematic diagram of the structure of the half-bridge power module provided in Embodiment 2 of the present invention;

[0040] Figure 3 This is a flowchart of a method for identifying fault types in a converter valve power module according to Embodiment 2 of the present invention;

[0041] Figure 4 This is a schematic diagram of the structure of the full-bridge power module provided in Embodiment 3 of the present invention;

[0042] Figure 5 This is a flowchart of a method for identifying fault types in a converter valve power module, provided in Embodiment 3 of the present invention. Detailed Implementation

[0043] This invention provides a method and apparatus for identifying fault types in a converter valve power module, which solves the technical problems of long time consumption and low efficiency in existing fault identification methods.

[0044] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0045] Example 1:

[0046] Please see Figure 1 This invention provides a method for identifying fault types in a converter valve power module. The power module includes a bypass thyristor, a bypass switch, and an IGBT assembly; the IGBT assembly includes a target IGBT device; when the power module is in the active state and a shoot-through fault exists, the method includes:

[0047] 101. Obtain the first target parameter, the second target parameter, the third target parameter, the bypass switch status, the bypass switch turn-on command issuance status, and the target IGBT device turn-on command issuance status.

[0048] It should be noted that the first, second, and third target parameters can be acquired from the power module. Specifically, the first target parameter is used to identify low-voltage breakdown of the bypass thyristor, the second target parameter is used to identify discharge faults in the bypass switch gap, and the third target parameter is used to identify IGBT device mis-triggering and IGBT device short-circuit failure faults. The bypass switch status includes closed and open states, and the target IGBT device turn-on command issuance status includes not issued and issued.

[0049] 102. Based on the comparison result between the first target parameter and the preset first parameter threshold, determine whether the bypass thyristor has a low-voltage breakdown fault. If so, determine the fault type as low-voltage breakdown of the bypass thyristor.

[0050] It should be noted that low-voltage breakdown of bypass thyristors refers to a fault phenomenon in which the PN junction of the thyristor undergoes reverse breakdown when the voltage is lower than the normal rated voltage of the bypass thyristor, resulting in the loss of its unidirectional conductivity and controllability.

[0051] 103. Based on the comparison result between the second target parameter and the preset second parameter threshold, the status of the bypass switch and the issuance status of the bypass switch conduction command, determine whether there is gap discharge in the bypass switch. If so, determine the fault type as bypass switch gap discharge.

[0052] It should be noted that bypass switch gap discharge refers to an undesirable discharge phenomenon that occurs in the gap between the electrodes of the bypass switch, resulting in the bypass switch failing to work properly or experiencing performance degradation.

[0053] 104. Based on the comparison result between the third target parameter and the preset third parameter threshold, and the issuance status of the target IGBT device turn-on command, determine whether the target IGBT device has a false triggering fault. If so, determine the fault type as IGBT device false triggering.

[0054] It should be noted that IGBT device erroneous triggering, also known as IGBT device interference-induced erroneous triggering, refers to an IGBT device entering a conducting state due to interference when it should not be conducting.

[0055] 105. Based on the comparison result of the third target parameter and the preset fourth parameter threshold, and the issuance status of the target IGBT device turn-on command, determine whether the target IGBT device has a short circuit failure fault. If so, determine the fault type as IGBT device short circuit failure fault.

[0056] It should be noted that the short-circuit failure of an IGBT device, also known as short-circuit failure under the rated voltage of the IGBT device, refers to the phenomenon that the device loses its normal function and cannot continue to work effectively when the voltage it withstands is its rated voltage.

[0057] It is understood that steps 102 to 105 do not have a specific order; they can be executed simultaneously or in the desired order as needed. The specific values ​​of the threshold values ​​for each parameter can be set according to the actual situation.

[0058] In this embodiment, by acquiring the first target parameter, the second target parameter, the third target parameter, the bypass switch status, the bypass switch turn-on command issuance status, and the target IGBT device turn-on command issuance status, and based on the comparison result of the first target parameter and the preset first parameter threshold, it is determined whether the bypass thyristor has experienced a low-voltage breakdown fault. If so, the fault type is determined to be bypass thyristor low-voltage breakdown, thus realizing the identification of bypass thyristor low-voltage breakdown. Furthermore, based on the comparison result of the second target parameter and the preset second parameter threshold, the bypass switch status, and the bypass switch turn-on command issuance status, it is determined whether there is gap discharge in the bypass switch. If so, the fault type is determined to be bypass switch gap discharge. This invention enables the identification of faults such as discharge in the bypass switch gap. Based on the comparison between the third target parameter and a preset third parameter threshold, and the issuance status of the target IGBT device's turn-on command, it determines whether the target IGBT device has a false triggering fault. If so, the fault type is determined to be IGBT device false triggering, thus achieving the identification of IGBT device false triggering faults. Furthermore, based on the comparison between the third target parameter and a preset fourth parameter threshold, and the issuance status of the target IGBT device's turn-on command, it determines whether the target IGBT device has a short-circuit failure fault. If so, the fault type is determined to be IGBT device short-circuit failure, thus achieving the identification of IGBT device short-circuit failure faults. As can be seen from the above, when the power module is in the activated state and a shoot-through fault exists, the identification method provided by this invention can quickly and accurately identify the faulty component and fault type without disassembling the power module. This solves the technical problems of long time consumption and low efficiency in existing power module fault identification methods, achieving the technical effect of reducing fault troubleshooting time and improving fault troubleshooting efficiency.

[0059] Furthermore, the power module types include half-bridge power modules or full-bridge power modules.

[0060] Example 2:

[0061] When the power module is a half-bridge power module, such as Figure 2As shown, its structure includes: a bypass thyristor SCR, a bypass switch S, an IGBT assembly, a first capacitor C1, and a first resistor R1; the IGBT assembly includes a first IGBT device T1 and a second IGBT device T2; the first IGBT device T1 is also provided with a parasitic diode D1, and the second IGBT device T2 is also provided with a parasitic diode D2; the bypass thyristor SCR, bypass switch S, and second IGBT device T2 are connected in parallel in sequence, the first IGBT device T1 and the second IGBT device T2 are connected in series, the first capacitor C1 is connected in parallel with the first IGBT device T1 and the second IGBT device T2, and the first resistor R1 is connected in parallel with the first capacitor C1; wherein, the bypass thyristor SCR, bypass switch S, and second IGBT device T2 are all connected in series with Hall sensors CT1, CT2, and CT3 respectively; the Hall sensors CT1, CT2, and CT3 are connected to the power module control board and are used to measure the current value I flowing through the bypass thyristor SCR, bypass switch S, and second IGBT device T2 in real time. SCR I S I T2 The signal is then sent to the power module control board; the driver board of the second IGBT device T2 is connected to the second IGBT device T2 and the power module control board, and is used to measure the voltage U between the collector and emitter of the second IGBT device T2 in real time. ceT2 The gate-emitter voltage U of the second IGBT device T2 geT2 And promptly send it to the power module control board.

[0062] Wherein, current I SCR I S I T2 Direction such as Figure 2 As shown, the arrow points in the positive direction. When the half-bridge power module is in the active state, the first IGBT device T1 is turned on and the second IGBT device T2 is turned off. If a shoot-through fault occurs in the DC capacitor of the half-bridge power module at this time, the fault type can be identified by the converter valve power module fault type identification method provided in the following embodiment of the invention, thereby determining the cause of the shoot-through fault in the half-bridge power module. In this embodiment, the target IGBT device is the IGBT device in the off state in the active half-bridge power module, that is, the target IGBT device in this embodiment is the second IGBT device T2.

[0063] Furthermore, such as Figure 3 As shown in the figure, an embodiment of the present invention provides a method for identifying fault types of a converter valve power module, which is applied to a power module control board. The specific steps include:

[0064] 201. Obtain the first target parameter, the second target parameter, the third target parameter, the bypass switch status, the bypass switch turn-on command issuance status, and the target IGBT device turn-on command issuance status.

[0065] It should be noted that the first target parameters include the current and first duration of the bypass thyristor, the first inter-electrode voltage and the second duration of the target IGBT device; the first parameter thresholds include the first voltage threshold, the first current threshold, the first time threshold and the second time threshold.

[0066] The second target parameters include the first inter-electrode voltage and the second duration of the target IGBT device, the current of the bypass switch, and the third duration; the second parameter thresholds include the first voltage threshold, the first time threshold, the second current threshold, and the third time threshold.

[0067] The third target parameters include: the first inter-electrode voltage and the second duration of the target IGBT device, the current and the fourth duration of the target IGBT device, and the second inter-electrode voltage and the fifth duration of the target IGBT device; the third parameter thresholds include: the first voltage threshold, the first time threshold, the third current threshold, the fourth time threshold, the target turn-on voltage, and the fifth time threshold.

[0068] Understandably, in this step, the voltage, current, and duration required to identify the fault type can be obtained in advance and classified into first target parameters, second target parameters, and third target parameters.

[0069] 202. When the first inter-electrode voltage is less than the first voltage threshold and the second duration exceeds the first time threshold, and the bypass thyristor current is greater than the first current threshold and the first duration exceeds the second time threshold, it is determined that the bypass thyristor has a low-voltage breakdown fault, and the fault type is bypass thyristor low-voltage breakdown.

[0070] It should be noted that the first inter-electrode voltage refers to the collector-emitter voltage U. ceT2 The second duration refers to the duration during which the voltage between the first electrodes is less than the first voltage threshold. It can be understood that when the voltage between the first electrodes is less than the first voltage threshold, the timing of the duration is activated, and the power module control board can obtain the first duration from its internal timing module. The first duration refers to the duration during which the current of the bypass thyristor is greater than the first current threshold; the principle behind its acquisition can be found in the section on the second duration, and will not be elaborated here.

[0071] In this embodiment, when the power module control board detects the collector-emitter voltage U of the second IGBT device T2... ceT2 The measured value (i.e., the voltage between the first electrodes) is less than the set voltage threshold U. set1(i.e., the first voltage threshold), and the duration exceeds the set time threshold T. set1 (i.e., the first time threshold), and simultaneously detect the current I of the bypass thyristor. SCR Greater than the set current threshold I set1 (i.e., the first current threshold) and the duration exceeds the set time threshold T. set2 (i.e., the second time threshold) When all the above conditions are met simultaneously, the power module control board identifies the fault type as "bypass thyristor low voltage breakdown" of the half-bridge power module and sends the identification result to the valve control system. Otherwise, it does not identify "bypass thyristor low voltage breakdown" of the half-bridge power module and does not send the result to the valve control system.

[0072] 203. When the voltage between the first poles is less than the first voltage threshold and the first duration exceeds the first time threshold, and the current of the bypass switch is greater than the second current threshold and the third duration exceeds the third time threshold, and the bypass switch conduction command is not issued, and the bypass switch is in the open state, it is determined that there is a gap discharge in the bypass switch, and the fault type is bypass switch gap discharge.

[0073] It should be noted that the third duration refers to the duration during which the current of the bypass switch is greater than the second current threshold.

[0074] In this embodiment, the power module control board detects the voltage U between the collector and emitter of the second IGBT device T2. ceT2 The measured value is less than the set voltage threshold U set1 And the duration exceeds the set time threshold T set1 At the same time, the current value I of the bypass switch S was detected. S greater than the set current threshold Iset2 And the duration exceeds the set time threshold T set3 Meanwhile, if the power module control board does not issue a bypass switch conduction command and the bypass switch status sent by the bypass switch driver board is still in the open state, the power module control board will identify the fault type as "bypass switch gap discharge" of the half-bridge power module and send the identification result to the valve control system. Otherwise, it will not identify "bypass switch gap discharge" of the half-bridge power module and will not send the result to the valve control system.

[0075] If the power module control board detects that the measured value of the collector-emitter voltage UceT2 of the second IGBT device T2 is less than the set voltage threshold Uset1 and the duration exceeds the set time threshold Tset1, and at the same time detects the current value I of the bypass switch S... S Greater than the set current threshold I set2 And the duration exceeds the set time threshold T set3Meanwhile, if the power module control board does not issue a bypass switch conduction command and the bypass switch status sent by the bypass switch driver board is still in the open state, the power module control board will identify the fault type as "bypass switch gap discharge" of the half-bridge power module and send the identification result to the valve control system. Otherwise, it will not identify "bypass switch gap discharge" of the half-bridge power module and will not send the result to the valve control system.

[0076] 204. When the first inter-electrode voltage is less than the first voltage threshold and the first duration exceeds the first time threshold, and the current of the target IGBT device is greater than the third current threshold and the fourth duration exceeds the fourth time threshold, and the target IGBT device turn-on command is not issued, and the second inter-electrode voltage is greater than the target turn-on voltage and the fifth duration is greater than the fifth time threshold, it is determined that the target IGBT device has a false triggering fault, and the fault type is IGBT device false triggering.

[0077] It should be noted that the fourth duration refers to the duration during which the current of the target IGBT device is greater than the third current threshold. The target turn-on voltage refers to the gate-emitter voltage value required for the target IGBT device to turn on.

[0078] In this embodiment, if the power module control board detects the collector-emitter voltage U of the second IGBT device T2... ceT2 The measured value is less than the set voltage threshold U set1 And the duration exceeds the set time threshold T set1 Simultaneously, the current value I of the second IGBT device T2 was detected. T2 Greater than the set current threshold I set3 And the duration exceeds the set time threshold T set4 Meanwhile, the power module control board did not issue a turn-on command for the lower IGBT T2, and detected the gate-emitter voltage U sent by the driver board of the second IGBT device T2. geT2 Greater than U ge开通 (The gate-emitter voltage required to turn on the device, typically around +12V) and the duration exceeds a set time threshold T. set5 If all the above conditions are met simultaneously, the power module control board identifies the fault type as "the second IGBT device is erroneously triggered due to interference" in the half-bridge power module and sends the identification result to the valve control system. Otherwise, it does not identify "the second IGBT device is erroneously triggered due to interference" in the half-bridge power module and does not send the result to the valve control system.

[0079] 205. When the first inter-electrode voltage is less than the first voltage threshold and the first duration exceeds the first time threshold, and the current of the target IGBT device is greater than the third current threshold and the fourth duration exceeds the fourth time threshold, and the target IGBT device turn-on command is not issued, and the second inter-electrode voltage is less than the target turn-on voltage and the fifth duration is greater than the fifth time threshold, it is determined that the target IGBT device has a short-circuit failure fault, and the fault type is IGBT device short-circuit failure fault.

[0080] It should be noted that the fourth parameter threshold includes the first voltage threshold, the first time threshold, the third current threshold, the fourth time threshold, the target turn-on voltage, and the sixth time threshold.

[0081] In this embodiment, if the power module control board detects the collector-emitter voltage U of the second IGBT device T2... ceT2 The measured value is less than the set voltage threshold U set1 And the duration exceeds the set time threshold T set1 Simultaneously, the current value I of the second IGBT device T2 was detected. T2 Greater than the set current threshold I set3 And the duration exceeds the set time threshold T set4 Meanwhile, the power module control board did not issue a turn-on command for the second IGBT device T2 and detected the gate-emitter voltage U sent by the driver board of the second IGBT device T2. geT2 Less than U ge开通 (The gate-emitter voltage required to turn on the device, typically around +12V) and the duration exceeds a set time threshold T. set6 If all the above conditions are met simultaneously, the power module control board identifies the fault type as "short circuit failure of the second IGBT device under rated voltage" of the half-bridge power module and sends the identification result to the valve control system. Otherwise, it does not identify "short circuit failure of the second IGBT device under rated voltage" of the half-bridge power module and does not send the result to the valve control system.

[0082] Based on the identification method provided in this embodiment of the invention, the fault type of shoot-through fault can be accurately identified, thereby precisely diagnosing faulty components and improving fault identification efficiency. It is understood that the identification method provided in this embodiment is applicable to both single-fault-type identification scenarios and scenarios involving multiple fault types. For example, assuming the detected shoot-through fault is caused by the superposition of multiple faults, the state of each component can still be identified separately according to steps 201 to 205 above to obtain the corresponding identification results. Finally, all identification results are combined to obtain all fault types that caused the shoot-through fault in the half-bridge power module.

[0083] It is understandable that steps 202 to 205 do not have a specific order and can be executed synchronously and in parallel.

[0084] Furthermore, the structure of the half-bridge power module may also include a third power switching device T3 and a second resistor R2. The third power switching device T3 is provided with a parasitic diode D3. The third power switching device T3 is connected in series with the second resistor R2, and then connected in parallel with the first resistor R1.

[0085] Example 3:

[0086] When the power module is a full-bridge power module, such as Figure 4 As shown, its structure includes a bypass thyristor SCR, a bypass switch S, an IGBT assembly, a first capacitor C1 and a first resistor R1, a first power switch T5, and a second resistor R2. The IGBT assembly includes a first IGBT device T1, a second IGBT device T2, a third IGBT device T3, and a fourth IGBT device T4. The first IGBT device T1, the second IGBT device T2, the third IGBT device T3, and the fourth IGBT device T4 are all equipped with parasitic diodes D1, D2, D3, and D4, respectively. The first power switch T5 is also equipped with a parasitic diode D5.

[0087] The bypass thyristor SCR, bypass switch S, and second IGBT device T2 are connected in parallel in sequence. The first IGBT device T1 and the second IGBT device T2 are connected in series. The first capacitor C1 is connected in parallel with the first IGBT device T1 and the second IGBT device T2. The first resistor R1 is connected in parallel with the first capacitor C1. The third IGBT device T3 and the fourth IGBT device T4 are connected in series and in parallel with the first resistor R1. The first power switch device T5 is connected in series with the second resistor R2 and in parallel with the first resistor R1.

[0088] In this configuration, the bypass thyristor SCR, bypass switch S, first IGBT device T1, second IGBT device T2, third IGBT device T3, and fourth IGBT device T4 are each connected in series with Hall sensors CT1, CT2, CT3, CT4, CT5, and CT6, respectively. Hall sensors CT1, CT2, CT3, CT4, CT5, and CT6 are connected to the power module control board and are used to measure the current I flowing through the bypass thyristor SCR, bypass switch S, first IGBT device T1, second IGBT device T2, third IGBT device T3, and fourth IGBT device T4 in real time. SCR I S I T1 I T2 I T3 I T4 And send it to the power module control board.

[0089] The driver board of the first IGBT device T1 is connected to the first IGBT device T1 and the power module control board, and is used to measure the collector-emitter voltage U of the first IGBT device T1 in real time. ceT1 The gate-emitter voltage U of the first IGBT device T1 geT1 And promptly send it to the power module control board.

[0090] The driver board of the second IGBT device T2 is connected to the second IGBT device T2 and the power module control board, and is used to measure the collector-emitter voltage U of the second IGBT device T2 in real time. ceT2 The gate-emitter voltage U of the second IGBT device T2 geT2 And promptly send it to the power module control board.

[0091] The driver board of the third IGBT device T3 is connected to the third IGBT device T3 and the power module control board, and is used to measure the collector-emitter voltage U of the third IGBT device T3 in real time. ceT3 The gate-emitter voltage U of the third IGBT device T3 geT3 And promptly send it to the power module control board.

[0092] The driver board of the fourth IGBT device T4 is connected to the fourth IGBT device T4 and the power module control board, and is used to measure the collector-emitter voltage U of the fourth IGBT device T4 in real time. ceT4 The gate-emitter voltage U of the fourth IGBT device T4 geT4 And promptly send it to the power module control board.

[0093] Wherein, current I SCR I S I T1 I T2 I T3 I T4 direction, such as Figure 4 As shown, the arrows indicate the positive direction. The full-bridge power module has two states: positive and negative. In the positive state, the first IGBT T1 and the fourth IGBT T4 are turned on, while the second IGBT T2 and the third IGBT T3 are turned off. In the negative state, the first IGBT T1 and the fourth IGBT T4 are turned off, while the second IGBT T2 and the third IGBT T3 are turned on.

[0094] If a shoot-through fault occurs in the DC capacitor of the full-bridge power module during the energization process, the fault type can be identified using the converter valve power module fault type identification method provided in the following embodiment of the invention, thereby determining the cause of the full-bridge power module shoot-through fault. In this embodiment, the target IGBT device includes any one of the two IGBT devices in the off state within the full-bridge power module in the energized state.

[0095] Furthermore, such as Figure 5 As shown in the figure, an embodiment of the present invention provides a method for identifying fault types of a converter valve power module, which is applied to a power module control board. The specific steps include:

[0096] 301. Obtain the first target parameter, the second target parameter, the third target parameter, the bypass switch status, the bypass switch turn-on command issuance status, and the target IGBT device turn-on command issuance status.

[0097] It should be noted that the first target parameters in this step include the current of the bypass thyristor and the first duration, the first inter-electrode voltage difference, the second inter-electrode voltage difference, and the sixth duration; the first parameter thresholds include the first voltage threshold, the first current threshold, the first time threshold, and the second time threshold. The second target parameters include the current of the bypass switch and the third duration, the first inter-electrode voltage difference, the second inter-electrode voltage difference, and the sixth duration; the second parameter thresholds include the first voltage threshold, the first time threshold, the second current threshold, and the third time threshold.

[0098] The voltage difference between the first electrodes is U. ceT2 -U ceT4 Among them, U ceT2 U is the collector-emitter voltage of the second IGBT device T2; ceT4 This is the collector-emitter voltage of the fourth IGBT device T4.

[0099] The voltage difference between the second electrodes is U. ceT3 -U ceT1 Among them, U ceT3 U is the collector-emitter voltage of the third IGBT device T3; ceT1 This is the collector-emitter voltage of the first IGBT device T1.

[0100] The sixth duration refers to the duration during which both the voltage difference between the first and second electrodes is less than the first voltage threshold.

[0101] It is understood that the first parameter threshold, the second parameter threshold, the third parameter threshold, and the fourth parameter threshold are the same as in Example 2, and for details, please refer to Example 2.

[0102] 302. When the voltage difference between the first and second electrodes is less than the first voltage threshold and the sixth duration exceeds the first time threshold, and the current of the bypass thyristor is greater than the first current threshold and the first duration exceeds the second time threshold, it is determined that the bypass thyristor has a low-voltage breakdown fault, and the fault type is bypass thyristor low-voltage breakdown.

[0103] It should be noted that in this step, when the voltage difference between the first and second electrodes is less than the first voltage threshold and the sixth duration exceeds the first time threshold, and the current of the bypass thyristor is greater than the first current threshold and the first duration exceeds the second time threshold, it indicates that the bypass thyristor has experienced a low-voltage breakdown fault. Therefore, it is determined that the bypass thyristor has experienced a low-voltage breakdown, and the fault type at this time is low-voltage breakdown of the bypass thyristor.

[0104] 303. When the voltage difference between the first and second poles is less than the first voltage threshold and the sixth duration exceeds the first time threshold, the current of the bypass switch is greater than the second current threshold and the third duration exceeds the third time threshold, the bypass switch conduction command is not issued, and the bypass switch is in the open state, it is determined that there is a gap discharge in the bypass switch, and the fault type is bypass switch gap discharge.

[0105] It should be noted that in this step, the voltage difference between the first and second poles is less than the first voltage threshold and the sixth duration exceeds the first time threshold, the current of the bypass switch is greater than the second current threshold and the third duration exceeds the third time threshold, the bypass switch conduction command is not issued, and the bypass switch is in the open state, indicating that there is a gap discharge in the bypass switch. Therefore, it is determined that there is a gap discharge in the bypass switch, that is, the fault type at this time is a bypass switch gap discharge.

[0106] 304. Based on the comparison result between the third target parameter and the preset third parameter threshold, and the issuance status of the target IGBT device turn-on command, determine whether the target IGBT device has a false triggering fault. If so, determine the fault type as IGBT device false triggering.

[0107] 305. Based on the comparison result of the third target parameter and the preset fourth parameter threshold, and the issuance status of the target IGBT device turn-on command, determine whether the target IGBT device has a short circuit failure fault. If so, determine the fault type as IGBT device short circuit failure fault.

[0108] It should be noted that the principle of step 304 is similar to that of step 204, and the principle of step 305 is similar to that of step 205. The difference is that, in this embodiment, when in the active input state, the target IGBT device is either the second IGBT device T2 or the third IGBT device T3.

[0109] When the target IGBT device is the second IGBT device T2, the current of the target IGBT device is the current of the second IGBT device T2, and the first inter-electrode voltage of the target IGBT device is the collector-emitter voltage of the second IGBT device T2.

[0110] When the target IGBT device is the third IGBT device T3, the current of the target IGBT device is the current of the third IGBT device T3, and the first inter-electrode voltage of the target IGBT device is the collector-emitter voltage of the third IGBT device T3.

[0111] When in a negative input state, the target IGBT device is the first IGBT device T1 or the fourth IGBT device T4.

[0112] When the target IGBT device is the first IGBT device T1, the current of the target IGBT device is the current of the first IGBT device T1, and the first inter-electrode voltage of the target IGBT device is the collector-emitter voltage of the first IGBT device T1.

[0113] When the target IGBT device is the fourth IGBT device T4, the current of the target IGBT device is the current of the fourth IGBT device T4, and the first inter-electrode voltage of the target IGBT device is the collector-emitter voltage of the fourth IGBT device T4.

[0114] It is understood that in this embodiment, steps 303 and 304 can be executed separately for each target IGBT device until the fault identification result of each target IGBT device is obtained. Steps 302 to 305 do not have a specific order and can be executed synchronously.

[0115] As can be seen from the above, when a shoot-through fault occurs in the full-bridge power module, the identification method provided in this embodiment can accurately identify the faulty component and fault type that caused the shoot-through fault in the full-bridge power module, reducing the time required for fault diagnosis and improving the efficiency of fault diagnosis.

[0116] In one application example, combining Figure 4 The structure shown further illustrates the identification method provided in Embodiment 3.

[0117] In this application example, the full-bridge power module can be divided into positive and negative states based on its activation status.

[0118] (a) When the full-bridge power module is in the active state, the first IGBT device T1 and the fourth IGBT device T4 are turned on, and the second IGBT device T2 and the third IGBT device T3 are turned off. If a shoot-through fault occurs in the DC capacitor of the full-bridge power module at this time, then:

[0119] (1) If the power module control board detects (U ceT2 -U ceT4 ) Measured value and (U ceT3 -U ceT1 The measured values ​​were all less than the set voltage threshold U. set1 And the duration exceeds the set time threshold T set1 Simultaneously, the bypass thyristor current I was detected. SCR Greater than the set current threshold I set1 And the duration exceeds the set time threshold T set2 If all the above conditions are met simultaneously, the power module control board identifies the fault type as "bypass thyristor low-voltage breakdown" of the full-bridge power module and sends the identification result to the valve control system. Otherwise, it does not identify "bypass thyristor low-voltage breakdown" of the full-bridge power module and does not send the result to the valve control system.

[0120] (2) If the power module control board detects (U) ceT2 -U ceT4 ) Measured value and (U ceT3 -U ceT1 The measured values ​​were all less than the set voltage threshold U. set1 And the duration exceeds the set time threshold T set1 At the same time, the current value I of the bypass switch S was detected. S Greater than the set current threshold I set2 And the duration exceeds the set time threshold T set3 Meanwhile, if the power module control board does not issue a bypass switch conduction command and the bypass switch status sent by the bypass switch driver board is still in the open state, the power module control board will identify the fault type as "bypass switch gap discharge" of the full-bridge power module and send the identification result to the valve control system. Otherwise, it will not identify "bypass switch gap discharge" of the full-bridge power module and will not send the result to the valve control system.

[0121] (3) If the power module control board detects the collector-emitter voltage U of the second IGBT device T2 (or the third IGBT device T3) ceT2 (or U) ceT3 The measured value is less than the set voltage threshold U. set1 And the duration exceeds the set time threshold T set1 Simultaneously, the current value I of the second IGBT device T2 (or the third IGBT device T3) is detected. T2 (or I)T3 () greater than the set current threshold I set3 And the duration exceeds the set time threshold T set4 Meanwhile, the power module control board did not issue a turn-on command for the second IGBT device T2 (or the third IGBT device T3), and detected the gate-emitter voltage U sent by the driver board of the second IGBT device T2 (or the third IGBT device T3). geT2 (or U) geT3 ) greater than U ge开通 (The gate-emitter voltage required to turn on the device, typically around +12V) and the duration exceeds a set time threshold T. set5 When all the above conditions are met simultaneously, the power module control board identifies the fault type as "IGBT device T2 (or the third IGBT device T3) of the full-bridge power module is 'IGBT device is erroneously triggered by interference'" and sends the identification result to the valve control system. Otherwise, it does not identify "IGBT device T2 (or the third IGBT device T3) of the full-bridge power module is erroneously triggered by interference" and does not send the result to the valve control system.

[0122] (4) If the power module control board detects the collector-emitter voltage U of the second IGBT device T2 (or the third IGBT device T3) ceT2 (or U) ceT3 The measured value is less than the set voltage threshold U. set1 And the duration exceeds the set time threshold T set1 Simultaneously, the current value I of the second IGBT device T2 (or the third IGBT device T3) is detected. T2 (or I) T3 () greater than the set current threshold I set3 And the duration exceeds the set time threshold T set4 Meanwhile, the power module control board did not issue a turn-on command for the second IGBT device T2 (or the third IGBT device T3) and detected the gate-emitter voltage U sent by the driver board of the second IGBT device T2 (or the third IGBT device T3). geT2 (or U) geT3 (less than U) ge开通 (The gate-emitter voltage required to turn on the device, typically around +12V) and the duration exceeds a set time threshold T. set6 When all the above conditions are met simultaneously, the power module control board identifies the fault type as "short circuit failure under rated voltage" of the second IGBT device T2 (or the third IGBT device T3) of the full-bridge power module, and sends the identification result to the valve control system. Otherwise, it does not identify "short circuit failure under rated voltage" of the second IGBT device T2 (or the third IGBT device T3) of the full-bridge power module, nor does it send the result to the valve control system.

[0123] Based on the identification method provided in this embodiment of the invention, the fault type of shoot-through fault can be accurately identified, thereby precisely diagnosing faulty components and improving fault identification efficiency. It is understood that the identification method provided in this embodiment is applicable to both single-fault-type identification scenarios and scenarios involving multiple fault types. For example, assuming the detected shoot-through fault is caused by the superposition of multiple faults, the state of each component can still be identified using the above method to obtain the corresponding identification results. Finally, all identification results are combined to obtain all fault types that cause shoot-through faults under the active state of the full-bridge power module.

[0124] (ii) When the full-bridge power module is in a negative input state, the second IGBT device T2 and the third IGBT device T3 are turned on, and the first IGBT device T1 and the fourth IGBT device T4 are turned off. If a shoot-through fault occurs in the DC capacitor of the full-bridge power module at this time, then:

[0125] (5) If the power module control board detects (U) ceT2 -U ceT4 ) Measured value and (U ceT3 -U ceT1 The measured values ​​were all less than the set voltage threshold U. set1 And the duration exceeds the set time threshold T set1 Simultaneously, the bypass thyristor current I was detected. SCR Greater than the set current threshold I set1 And the duration exceeds the set time threshold T set2 If all the above conditions are met simultaneously, the power module control board identifies the fault type as "bypass thyristor low-voltage breakdown" of the full-bridge power module and sends the identification result to the valve control system. Otherwise, it does not identify "bypass thyristor low-voltage breakdown" of the full-bridge power module and does not send the result to the valve control system.

[0126] (6) If the power module control board detects (U) ceT2 -U ceT4 ) Measured value and (U ceT3 -U ceT1 The measured values ​​were all less than the set voltage threshold U. set1 And the duration exceeds the set time threshold T set1 At the same time, the current value I of the bypass switch S was detected. S Greater than the set current threshold I set2 And the duration exceeds the set time threshold T set3Meanwhile, if the power module control board does not issue a bypass switch conduction command and the bypass switch status sent by the bypass switch driver board is still in the open state, the power module control board will identify the fault type as "bypass switch gap discharge" of the full-bridge power module and send the identification result to the valve control system. Otherwise, it will not identify "bypass switch gap discharge" of the full-bridge power module and will not send the result to the valve control system.

[0127] (7) If the power module control board detects the collector-emitter voltage U of the first IGBT device T1 (or the fourth IGBT device T4) ceT1 (or U) ceT4 The measured value is less than the set voltage threshold U. set1 And the duration exceeds the set time threshold T set1 Simultaneously, the current value I of IGBT T1 (or IGBT T4) is detected. T1 (or I) T4 () greater than the set current threshold I set3 And the duration exceeds the set time threshold T set4 Meanwhile, the power module control board did not issue a turn-on command for the first IGBT device T1 (or the fourth IGBT device T4), and detected the gate-emitter voltage U sent by the driver board of the first IGBT device T1 (or the fourth IGBT device T4). geT1 (or U) geT4 ) greater than U ge开通 (The gate-emitter voltage required to turn on the device, typically around +12V) and the duration exceeds a set time threshold T. set5 When all the above conditions are met simultaneously, the power module control board identifies the fault type as "IGBT device T1 (or fourth IGBT device T4) of the full-bridge power module is 'IGBT device is erroneously triggered by interference'" and sends the identification result to the valve control system. Otherwise, it does not identify "IGBT device T1 (or fourth IGBT device T4) of the full-bridge power module is erroneously triggered by interference" and does not send the result to the valve control system.

[0128] (8) If the power module control board detects the voltage U between the collector and emitter of the first IGBT device T1 (or the fourth IGBT device T4) ceT1 (or U) ceT4 The measured value is less than the set voltage threshold U. set1 And the duration exceeds the set time threshold T set1 Simultaneously, the current value I of IGBT T1 (or IGBT T4) is detected. T1 (or I) T4 () greater than the set current threshold I set3 And the duration exceeds the set time threshold T set4Meanwhile, the power module control board did not issue a turn-on command for the first IGBT device T1 (or the fourth IGBT device T4) and detected the gate-emitter voltage U sent by the driver board of the first IGBT device T1 (or the fourth IGBT device T4). geT1 (or U) geT4 (less than U) ge开通 (The gate-emitter voltage required to turn on the device, typically around +12V) and the duration exceeds a set time threshold T. set6 When all the above conditions are met simultaneously, the power module control board identifies the fault type as "short circuit failure under rated voltage of the first IGBT device T1 (or the fourth IGBT device T4) of the full-bridge power module" and sends the identification result to the valve control system. Otherwise, it does not identify "short circuit failure under rated voltage of the first IGBT device T1 (or the fourth IGBT device T4) of the full-bridge power module" and does not send the result to the valve control system.

[0129] Based on the identification method provided in this embodiment of the invention, the fault type of shoot-through fault can be accurately identified, thereby precisely diagnosing faulty components and improving fault identification efficiency. It is understood that the identification method provided in this embodiment is applicable to both single-fault-type identification scenarios and scenarios involving multiple fault types. For example, assuming the detected shoot-through fault is caused by the superposition of multiple faults, the state of each component can still be identified using the above method to obtain the corresponding identification results. Finally, all identification results are combined to obtain all fault types that cause shoot-through faults under the negative input state of the full-bridge power module.

[0130] In one embodiment, a fault type identification device for a converter valve power module is also provided, the device including a processor and a memory;

[0131] The memory is used to store program code and transfer the program code to the processor;

[0132] The processor is used to execute the methods of any of the above embodiments according to instructions in the program code.

[0133] The identification method and apparatus proposed in this invention, when the power module of the flexible DC converter valve is unlocked and in an "engaged state" (half-bridge power module in engaged state, full-bridge power module in positive or negative engaged state), can accurately identify which component within the module is causing the shoot-through fault if a DC capacitor shoot-through fault occurs. The identifiable component fault types include: IGBT device mis-triggered by interference, short-circuit failure under rated voltage, bypass switch gap discharge, and thyristor low-voltage breakdown. Therefore, this invention can accurately identify the faulty device and fault type causing the shoot-through fault, improving the efficiency of fault identification and solving the technical problems of long time consumption and low efficiency in existing fault identification methods.

[0134] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0135] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0136] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0137] Furthermore, in the various embodiments of the present invention, the functional units can be integrated into one processing unit, or each functional unit can be a separate physical entity, or two or more functional units can be integrated into one processing unit. The integrated unit described above can be implemented in hardware or as a software functional unit.

[0138] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0139] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0140] It should also be noted that in the description of this invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0141] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for identifying fault types in a converter valve power module, characterized in that, The power module includes a bypass thyristor, a bypass switch, and an IGBT assembly; the IGBT assembly includes a target IGBT device. When the power module is in the active state and a shoot-through fault exists, the method includes: The system acquires the first target parameter, the second target parameter, the third target parameter, the bypass switch status, the bypass switch turn-on command issuance status, and the target IGBT device turn-on command issuance status. The first target parameter is used to identify low-voltage breakdown of the bypass thyristor. The second target parameter is used to identify bypass switch gap discharge faults. The third target parameter is used to identify IGBT device false triggering and IGBT device short-circuit failure faults. Based on the comparison result between the first target parameter and the preset first parameter threshold, it is determined whether the bypass thyristor has a low-voltage breakdown fault. If so, the fault type is determined to be low-voltage breakdown of the bypass thyristor. Based on the comparison result between the second target parameter and the preset second parameter threshold, the status of the bypass switch and the issuance status of the bypass switch conduction command, it is determined whether there is a gap discharge in the bypass switch. If so, the fault type is determined to be a bypass switch gap discharge. Based on the comparison result between the third target parameter and the preset third parameter threshold, and the issuance status of the target IGBT device turn-on command, it is determined whether the target IGBT device has a false triggering fault. If so, the fault type is determined to be IGBT device false triggering. Based on the comparison result between the third target parameter and the preset fourth parameter threshold, and the issuance status of the target IGBT device turn-on command, it is determined whether the target IGBT device has a short-circuit failure fault. If so, the fault type is determined to be an IGBT device short-circuit failure fault.

2. The method according to claim 1, characterized in that, The first target parameters include the current and first duration of the bypass thyristor, the first inter-electrode voltage and the second duration of the target IGBT device; The first parameter threshold includes a first voltage threshold, a first current threshold, a first time threshold, and a second time threshold; The step of determining whether the bypass thyristor has experienced a low-voltage breakdown fault based on the comparison result between the first target parameter and the preset first parameter threshold includes: When the first inter-electrode voltage is less than the first voltage threshold and the second duration exceeds the first time threshold, and the current of the bypass thyristor is greater than the first current threshold and the first duration exceeds the second time threshold, it is determined that the bypass thyristor has a low-voltage breakdown fault. The second duration refers to the duration during which the first inter-electrode voltage is less than the first voltage threshold. The first duration refers to the duration during which the current of the bypass thyristor is greater than the first current threshold.

3. The method according to claim 2, characterized in that, The second target parameters include the first inter-electrode voltage and the second duration of the target IGBT device, the current of the bypass switch, and the third duration; The second parameter threshold includes the first voltage threshold, the first time threshold, the second current threshold, and the third time threshold; The step of determining whether there is gap discharge in the bypass switch based on the comparison result between the second target parameter and the preset second parameter threshold, the status of the bypass switch, and the issuance status of the bypass switch conduction command includes: When the first inter-electrode voltage is less than the first voltage threshold and the second duration exceeds the first time threshold, and the current of the bypass switch is greater than the second current threshold and the third duration exceeds the third time threshold, and the bypass switch conduction command is not issued, and the bypass switch is in the open state, it is determined that there is a gap discharge in the bypass switch. The third duration refers to the duration during which the current of the bypass switch is greater than the second current threshold.

4. The method according to claim 3, characterized in that, The third target parameter includes: the first inter-electrode voltage and the second duration of the target IGBT device, the current and the fourth duration of the target IGBT device, and the second inter-electrode voltage and the fifth duration of the target IGBT device; the third parameter threshold includes: the first voltage threshold, the first time threshold, the third current threshold, the fourth time threshold, the target on-voltage, and the fifth time threshold; The step of determining whether the target IGBT device has a false triggering fault based on the comparison result between the third target parameter and the preset third parameter threshold, and the issuance status of the target IGBT device turn-on command, includes: When the first inter-electrode voltage is less than the first voltage threshold and the second duration exceeds the first time threshold, and the current of the target IGBT device is greater than the third current threshold and the fourth duration exceeds the fourth time threshold, and the target IGBT device turn-on command is not issued, and the second inter-electrode voltage is greater than the target turn-on voltage and the fifth duration is greater than the fifth time threshold, it is determined that the target IGBT device has a false triggering fault. The fourth duration refers to the duration during which the current of the target IGBT device is greater than the third current threshold; the fifth duration refers to the duration during which the second inter-electrode voltage is greater than the target turn-on voltage.

5. The method according to claim 4, characterized in that, The fourth parameter threshold includes the first voltage threshold, the first time threshold, the third current threshold, the fourth time threshold, the target on-state voltage, and the sixth time threshold; The step of determining whether the target IGBT device has a short-circuit failure based on the comparison result of the third target parameter and the preset fourth parameter threshold, and the issuance status of the target IGBT device turn-on command, includes: When the first inter-electrode voltage is less than the first voltage threshold and the second duration exceeds the first time threshold, and the current of the target IGBT device is greater than the third current threshold and the fourth duration exceeds the fourth time threshold, and the target IGBT device turn-on command is not issued, and the second inter-electrode voltage is less than the target turn-on voltage and the fifth duration is greater than the fifth time threshold, it is determined that the target IGBT device has a short-circuit failure fault.

6. The method according to claim 1, characterized in that, When the power module is a full-bridge power module, the IGBT assembly includes a first IGBT device, a fourth IGBT device, a second IGBT device, and a third IGBT device; the first target parameter includes the bypass thyristor current and a first duration, a first inter-electrode voltage difference, a second inter-electrode voltage difference, and a sixth duration; The first parameter threshold includes a first voltage threshold, a first current threshold, a first time threshold, and a second time threshold; the first inter-electrode voltage difference is the difference between the collector-emitter voltage of the second IGBT device and the collector-emitter voltage of the fourth IGBT device; the second inter-electrode voltage difference is the difference between the collector-emitter voltage of the third IGBT device and the collector-emitter voltage of the first IGBT device. The step of determining whether the bypass thyristor has experienced a low-voltage breakdown fault based on the comparison result between the first target parameter and the preset first parameter threshold includes: When the voltage difference between the first and second electrodes is less than the first voltage threshold and the sixth duration exceeds the first time threshold, and the current of the bypass thyristor is greater than the first current threshold and the first duration exceeds the second time threshold, it is determined that the bypass thyristor has a low-voltage breakdown fault. The sixth duration refers to the duration during which both the first inter-electrode voltage difference and the second inter-electrode voltage difference are less than the first voltage threshold. The first duration refers to the duration during which the current of the bypass thyristor is greater than the first current threshold.

7. The method according to claim 6, characterized in that, The second target parameters include the current of the bypass switch, the third duration, the first inter-electrode voltage difference, the second inter-electrode voltage difference, and the sixth duration; The second parameter threshold includes the first voltage threshold, the first time threshold, the second current threshold, and the third time threshold; The step of determining whether there is gap discharge in the bypass switch based on the comparison result between the second target parameter and the preset second parameter threshold, the status of the bypass switch, and the issuance status of the bypass switch conduction command includes: When the voltage difference between the first and second electrodes is less than the first voltage threshold and the sixth duration exceeds the first time threshold, the current of the bypass switch is greater than the second current threshold and the third duration exceeds the third time threshold, the bypass switch conduction command is not issued and the bypass switch is in the open state, it is determined that there is a gap discharge in the bypass switch. The third duration refers to the duration during which the current of the bypass switch is greater than the second current threshold.

8. The method according to claim 5, characterized in that, When the power module is a half-bridge power module, the target IGBT device is an IGBT device that is in the off state in the half-bridge power module that is in the on state.

9. The method according to claim 5, characterized in that, When the power module is a full-bridge power module, the target IGBT device includes either one of the two IGBT devices in the off state within the full-bridge power module that is in the on state.

10. A fault type identification device for a converter valve power module, characterized in that, The device includes a processor and a memory; The memory is used to store program code and transmit the program code to the processor; The processor is configured to execute the method as described in any one of claims 1-9 according to instructions in the program code.

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