Test circuit design method and system for flexible DC converter valve full-bridge module

Abstract

The present invention provides a test circuit design method and system for a flexible DC converter valve full-bridge module. The implementation scheme is: when the device properties of each insulated gate bipolar transistor in the full-bridge module have long-term failure current-carrying capacity, the full-bridge module is connected in parallel with a bypass switch to obtain a first test circuit; in the first test circuit, each insulated gate bipolar transistor is controlled to be turned on, and the conduction current of each transistor is gradually increased to a target current, and when the duration is greater than a threshold, the bypass switch is controlled to be closed, and the test voltage and test current of each transistor are measured to obtain the voltage change curve and current change curve of each transistor; when the voltage change curve of any transistor does not meet the preset conditions, the target turning thyristor is determined based on the voltage change curve and the current change curve; the insulated gate bipolar transistor in the full-bridge module is connected in parallel with the target turning thyristor to obtain a second test circuit to improve the test accuracy.

Description

Technical Field

[0001] The present invention relates to the field of information security technology, and in particular to a test circuit design method and system for a flexible DC converter valve full-bridge module. Background Art

[0002] Flexible DC transmission technology (Voltage Source Converter based High Voltage Direct Current Transmission, VSC-HVDC) is a DC transmission technology that uses fully controlled devices such as IGBT as core power devices. Compared with conventional DC transmission (LCC-HVDC) technology, it has advantages in reactive power compensation capability, no need for supporting power supply, no commutation failure, and flexible power control.

[0003] Therefore, in application scenarios such as distributed energy grid connection, AC grid back-to-back projects, island system power supply, and deep sea wind power transmission, flexible DC transmission technology is generally used as the transmission method.

[0004] However, with the increase in the capacity of converter valve projects and full-bridge modules, in extreme working conditions, the devices in the full-bridge module are prone to overvoltage breakdown, which can cause a direct short circuit of the capacitor and release millions of amperes of energy in a short period of time. This has an adverse effect on the safe operation of the full-bridge module body and the entire converter valve system. Therefore, it is crucial to design a second test circuit to verify the protection performance of the full-bridge module under extreme fault conditions to improve the performance of the full-bridge module. Summary of the invention

[0005] The present invention provides a test circuit design method and system for a flexible DC converter valve full-bridge module, which can solve at least one of the above technical problems.

[0006] According to one aspect of the present invention, a test circuit design method for a flexible DC converter valve full-bridge module is provided, comprising:

[0007] When the device property of each insulated gate bipolar transistor in the full-bridge module is a device with long-term failure current-carrying capability, each of the insulated gate bipolar transistors in the full-bridge module is connected in parallel with a bypass switch to obtain a first test circuit;

[0008] In the first test circuit, each of the insulated gate bipolar transistors is controlled to be turned on, and the on-current of each of the insulated gate bipolar transistors is gradually increased to a first target current;

[0009] When the duration of the on-state current of each of the insulated gate bipolar transistors in the first test circuit reaching the first target current is greater than a first time threshold, controlling the bypass switch in the first test circuit to close, and measuring the test voltage and the test current of each of the insulated gate bipolar transistors in the first test circuit to obtain a voltage change curve and a current change curve of each of the insulated gate bipolar transistors;

[0010] In the case where the voltage variation curve of any of the insulated gate bipolar transistors does not meet the preset voltage variation condition, determining a target turning thyristor based on the voltage variation curve and the current variation curve;

[0011] The insulated gate bipolar transistor in the full-bridge module is connected in parallel with the target turning thyristor to obtain a second test circuit for the full-bridge module.

[0012] According to another aspect of the present invention, a test circuit design device for a flexible DC converter valve full-bridge module is provided, comprising:

[0013] A first circuit determination module is used to connect each of the insulated gate bipolar transistors in the full-bridge module in parallel with a bypass switch to obtain a first test circuit when the device attribute of each of the insulated gate bipolar transistors in the full-bridge module is a device with long-term failure current-carrying capacity;

[0014] A first control module, configured to control each of the insulated gate bipolar transistors to be turned on in the first test circuit, and to gradually increase the on-current of each of the insulated gate bipolar transistors to a first target current;

[0015] a second control module, configured to control the bypass switch in the first test circuit to close when the duration of the on-current of each of the insulated gate bipolar transistors in the first test circuit reaching the first target current is greater than a first time threshold, and to measure the test voltage and the test current of each of the insulated gate bipolar transistors in the first test circuit to obtain a voltage change curve and a current change curve of each of the insulated gate bipolar transistors;

[0016] A thyristor determination module, configured to determine a target turning thyristor based on the voltage change curve and the current change curve when the voltage change curve of any of the insulated gate bipolar transistors does not meet a preset voltage change condition;

[0017] The second circuit determination module is used to connect the insulated gate bipolar transistor in the full-bridge module in parallel with the target turning thyristor to obtain a second test circuit for the full-bridge module.

[0018] By adopting the technical solution of the present invention, when it is known that the device properties of each insulated gate bipolar transistor in the full-bridge module are devices with long-term failure current-carrying capacity, verification needs to be performed again. Specifically, each insulated gate bipolar transistor in the full-bridge module is connected in parallel with a bypass switch to obtain a first test circuit. In the first test circuit, each insulated gate bipolar transistor is controlled to be turned on, and the on-current of each insulated gate bipolar transistor is gradually increased to a first target current. When the duration of the current is greater than a first time threshold, the bypass switch in the first test circuit is controlled to be closed, and the test voltage and test current of each insulated gate bipolar transistor in the first test circuit are measured to obtain the voltage change curve and current change curve of each insulated gate bipolar transistor. At this time, if the voltage change curve of any of the insulated gate bipolar transistors does not meet the preset voltage change conditions, it is determined that there is an insulated gate bipolar transistor in the full-bridge module that does not have the long-term failure current-carrying capacity. The voltage change curve and the current change curve can be obtained based on the simulation to determine the target turning thyristor; and the insulated gate bipolar transistor in the full-bridge module is connected in parallel with the target turning thyristor to obtain a second test circuit, which can be used to test the corresponding full-bridge module under real environment tests to improve test accuracy.

[0019] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to better understand the present invention and do not constitute a limitation of the present invention.

[0021] Figure 1 It is a flow chart of a test circuit design method of a flexible DC converter valve full-bridge module according to an embodiment of the present invention;

[0022] Figure 2 is a schematic diagram of a test circuit according to an embodiment of the present invention;

[0023] Figure 3 is a schematic diagram of a test circuit according to another embodiment of the present invention;

[0024] Figure 4 is a schematic diagram of a test circuit according to another embodiment of the present invention;

[0025] Figure 5 is a schematic diagram of a test circuit according to another embodiment of the present invention;

[0026] Figure 6 It is a structural block diagram of a test circuit design device for a flexible DC converter valve full-bridge module according to an embodiment of the present invention;

[0027] Figure 7 The block diagram is a block diagram of an electronic device for implementing the method according to the embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following is a description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, including various details of the embodiments of the present invention to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope of the present invention. Similarly, for clarity and conciseness, the description of well-known functions and structures is omitted in the following description.

[0029] Figure 1 It is a flow chart of a test circuit design method for a flexible DC converter valve full-bridge module according to an embodiment of the present invention.

[0030] like Figure 1 As shown, the test circuit design method of the flexible DC converter valve full-bridge module may include:

[0031] S110, when the device attribute of each insulated gate bipolar transistor in the full-bridge module is a device with long-term failure current-carrying capability, each insulated gate bipolar transistor in the full-bridge module is connected in parallel with a bypass switch to obtain a first test circuit;

[0032] S120, in the first test circuit, controlling each insulated gate bipolar transistor to be turned on, and gradually increasing the on-current of each insulated gate bipolar transistor to a first target current;

[0033] S130, when the duration of the on-state current of each insulated gate bipolar transistor in the first test circuit reaching the first target current is greater than the first time threshold, controlling the bypass switch in the first test circuit to close, and measuring the test voltage and the test current of each insulated gate bipolar transistor in the first test circuit to obtain the voltage change curve and the current change curve of each insulated gate bipolar transistor;

[0034] S140, when the voltage change curve of any insulated gate bipolar transistor does not meet the preset voltage change condition, determine a target turning thyristor based on the voltage change curve and the current change curve;

[0035] S150, connecting the insulated gate bipolar transistor in the full-bridge module in parallel with the target transition thyristor to obtain a second test circuit for the full-bridge module.

[0036] For example, the second test circuit of the embodiment of the present invention can be applied to a circuit for conducting a circuit test on a full-bridge module in a real environment. For example, the second test circuit is tested for bypass switch refusal to operate or bridge arm direct short circuit.

[0037] Exemplarily, the press-fit structure of the full-bridge module may include a double-string independent press-fit type, a double-string non-independent press-fit type, and a single-string press-fit type.

[0038] For example, the two strings in the dual-string independent crimping full-bridge module are relatively independent in terms of physical and electrical connections. Each string can independently complete basic electrical functions and has its own complete combination of IGBTs, diodes and other components. When conducting destructive tests, the full-bridge module can be used to conduct tests using one of the independently crimped half-bridge modules. The equivalent half-bridge module can be referenced Figure 2 and Figure 3 This means that the two strings have similarities and independence in test characteristics and electrical performance, have little influence on each other, are independent of each other in electrical connection and function realization, and each has a complete circuit function path. Figure 3 The circuit structure except the turning thyristor T is an equivalent half-bridge module.

[0039] For example, the two strings of the double-string non-independent crimping type are physically or electrically related to each other, and it is not possible to perform an equivalent test with one string as in the case of double-string independent crimping. Figure 4 and Figure 5 From the second test circuit of this structure, it can be seen that the full-bridge module structure must be used when conducting the test. This shows that the structures or electrical characteristics of the two strings are closely connected, and the working state of one string will significantly affect the other string. In the test, the two strings need to be considered as a whole. The two strings together constitute a complete circuit function. Without any string, the function of the full-bridge module cannot be realized normally.

[0040] For example, a single-string crimped full-bridge submodule contains only one complete circuit structure, without a repetitive structure like a double-string. All its insulated gate bipolar transistors (IGBTs), diodes, capacitors and other components form a single circuit path to achieve the function. Since there is only one string, the full-bridge module complete structure is also used during the test. Similar to the double-string non-independent crimped type, the performance of this string needs to be considered as a whole, and its electrical performance and structural integrity are crucial to the functional realization of the entire submodule.

[0041] Exemplarily, the device property of the insulated gate bipolar transistor may be having long-term failure current-carrying capability or not having long-term failure current-carrying capability.

[0042] For insulated gate bipolar transistors with long-term failure current conduction capability, when a fault occurs (such as bypass switch refusal to operate), this type of IGBT can continue to conduct current for a certain period of time without immediate damage. In the bypass switch refusal test, even if the diode is damaged and causes direct discharge, the IGBT with long-term current conduction capability can still maintain the circuit's on state for a period of time, which reflects its current conduction stability in the case of failure, which means that it can withstand abnormal current for a long time and will not fail quickly due to short-term fault current.

[0043] For IGBTs that do not have long-term failure current-carrying capacity, under the same fault conditions, such as bypass switch failure or bridge arm direct short circuit, these IGBTs cannot withstand the fault current for a long time. In the test, once direct discharge occurs, the IGBT may be quickly damaged by overcurrent, so a turning thyristor is required to assist in protection. This shows that when facing abnormal current, its tolerance time is short, and it relies heavily on additional protection mechanisms, and it may lose normal function due to excessive current in a short time.

[0044] For example, Figures 2 to 5 As shown, a bypass switch (not shown) is connected in parallel to the two output ends of the full-bridge module (the two leftmost terminals of the circuit in the figure), and the first test circuit is obtained. When the full-bridge module is a double-string independent crimping type, a string of independent crimping type is extracted from the full-bridge module as an equivalent half-bridge module, such as Figure 2 and Figure 3 As shown, bypass switches are connected in parallel at two output ends of the equivalent half-bridge module, so that a first test circuit can be obtained.

[0045] Exemplarily, the resistance of the bypass switch is 1 ohm or 2 ohms, etc.

[0046] Exemplarily, the first target current may be 2 times or 3 times, etc., of the rated current of the IGBT.

[0047] Exemplarily, the first time threshold may be 5 seconds or 10 seconds.

[0048] Exemplarily, if the test voltage across the insulated gate bipolar transistor remains less than the first preset voltage threshold for a period of time, it means that the insulated gate bipolar transistor does have a good failure current-carrying capability, and if the test voltage across the insulated gate bipolar transistor is boosted in a short period of time and the boosted voltage is greater than the second preset voltage threshold, it means that the insulated gate bipolar transistor does not have a good failure current-carrying capability. The second preset voltage threshold is greater than the first preset voltage threshold.

[0049] Exemplarily, if the IGBT does not have long-term failure current-carrying capability, the full-bridge module needs to be connected in parallel with a turning thyristor to form a test circuit. If the IGBT has long-term failure current-carrying capability, the full-bridge module may not be connected in parallel with a turning thyristor to form a test circuit.

[0050] According to the above implementation, when it is known that the device properties of each insulated gate bipolar transistor in the full-bridge module are devices with long-term failure current-carrying capacity, verification needs to be performed again. Specifically, each insulated gate bipolar transistor in the full-bridge module is connected in parallel with a bypass switch to obtain a first test circuit. In the first test circuit, each insulated gate bipolar transistor is controlled to be turned on, and the on-current of each insulated gate bipolar transistor is gradually increased to a first target current. When the duration of the current is greater than a first time threshold, the bypass switch in the first test circuit is controlled to be closed, and the test voltage and test current of each insulated gate bipolar transistor in the first test circuit are measured to obtain the voltage change curve and current change curve of each insulated gate bipolar transistor. At this time, if the voltage change curve of any of the insulated gate bipolar transistors does not meet the preset voltage change conditions, it is determined that there is an insulated gate bipolar transistor in the full-bridge module that does not have the long-term failure current-carrying capacity. The voltage change curve and the current change curve can be obtained based on the simulation to determine the target turning thyristor; and the insulated gate bipolar transistor in the full-bridge module is connected in parallel with the target turning thyristor to obtain a second test circuit, which can be used to test the corresponding full-bridge module under real environment tests to improve test accuracy.

[0051] In one embodiment, when the voltage change curve of any insulated gate bipolar transistor does not meet the preset voltage change condition, a target turning thyristor is determined based on the voltage change curve and the current change curve, including: when the continuous time of the voltage in the first interval in the voltage change curve of the first insulated gate bipolar transistor is less than the second time threshold, updating the device properties of the first insulated gate bipolar transistor to a device that does not have long-term failure current-carrying capacity; determining the forward turning voltage of the target turning thyristor based on the average voltage of the voltage change curve in a non-first interval; and determining the rated current of the target turning thyristor based on the average current of the current change curve in the first interval.

[0052] It can be understood that the first insulated gate bipolar transistor can be any insulated gate bipolar transistor in the first test circuit. After the bypass switch in the first test circuit is controlled to be closed, a short-circuit current can be generated. At this time, the voltage of the first insulated gate bipolar transistor rises. If the continuous time of the voltage after the rise from less than a voltage threshold to greater than the voltage threshold is less than the second time threshold, it means that the device attribute of the bipolar transistor is a device without long-term failure current-carrying capability. If the voltage after the rise is less than the voltage threshold, for example, 5V, and the continuous time of the voltage below the voltage threshold is greater than the second time threshold, it means that the device attribute of the bipolar transistor is a device with long-term failure current-carrying capability.

[0053] For bipolar transistors whose device attributes are devices that do not have long-term failure current-carrying capacity, the attributes are updated, and a target turning thyristor that needs to be connected in parallel to the full-bridge module is determined.

[0054] For bipolar transistors whose device attribute is a device with long-term failure current-carrying capability, no subsequent operation is performed.

[0055] It can be understood that the first interval is a time interval when the voltage changes from being less than a voltage threshold to being greater than the voltage threshold, and the non-first interval is a time interval other than the first interval.

[0056] Exemplarily, the average voltage in the non-first interval of the voltage variation curve is used as the forward break voltage of the target break thyristor.

[0057] Exemplarily, the average current in the first interval of the current variation curve is used as the rated current of the target transition thyristor.

[0058] According to the above implementation, when the device attribute of the bipolar transistor is determined to be a device without long-term failure current-carrying capacity, the forward breakover voltage and rated current of the target breakover thyristor are accurately determined based on the voltage change curve and current change curve recorded during the determination process. Subsequently, the target breakover thyristor is connected in parallel with the full-bridge module as a second test circuit, which can improve the test accuracy when applied to actual tests.

[0059] In some embodiments, if a target turning thyristor that matches the forward turning voltage and the rated current cannot be found among the thyristors, a target turning thyristor that matches the forward turning voltage or the rated current can be found, and the target turning thyristor is combined with a voltage, a resistor, a capacitor or a diode in series and in parallel to form a side circuit, and the side circuit is used as a second test circuit when connected in parallel with the full-bridge module.

[0060] In one embodiment, the above method may also include: measuring the test voltage and test current of each diode in the first test circuit while controlling the bypass switch in the first test circuit to be closed; determining the degree of influence of each insulated gate bipolar transistor based on the test voltage and test current of each insulated gate bipolar transistor; determining the degree of influence of each diode based on the test voltage and test current of each diode; determining the device to be replaced in each insulated gate bipolar transistor and each diode based on the degree of influence of each insulated gate bipolar transistor and the degree of influence of each diode; determining the target replacement device based on the degree of influence of the device to be replaced; and replacing the device to be replaced with the target replacement device in the second test circuit.

[0061] Exemplarily, the degree of change of the test voltage and test current of the insulated gate bipolar transistor relative to the test voltage and test current under normal operation determines the degree of its impact. The smaller the degree of change, the smaller the degree of impact, and the greater the degree of change, the greater the degree of impact.

[0062] Exemplarily, among the insulated gate bipolar transistors and the diodes, the devices whose affected degree is greater than a preset degree threshold are selected as the devices to be replaced.

[0063] Exemplarily, based on the impact degree of the device to be replaced, the device type of the target replacement device is determined, and the device type includes an insulating block or a metal block.

[0064] Exemplarily, the device type of the target replacement device is determined based on the test voltage and test current of the device to be replaced.

[0065] In one embodiment, based on the degree of impact of the component to be replaced, a target replacement component is determined, including: when the degree of impact of the component to be replaced is greater than a first degree threshold, determining the target replacement component to be an insulating block; when the degree of impact of the component to be replaced is less than the first degree threshold and greater than a second degree threshold, determining the target replacement component to be a metal block; wherein the first degree threshold is greater than the second degree threshold.

[0066] like Figure 4 and Figure 5 As shown in the figure, although the reverse-parallel diode D2 may be damaged by oscillation during the straight-through discharge process, it is not a device that will explode directly. Metal has good conductivity. Replacing the reverse-parallel diode D2 with a metal block can simulate some of the electrical properties of D2 to a certain extent. Compared with the insulating block, the metal block can conduct current better and help maintain the partial conduction state of the circuit, thereby more accurately simulating the electrical behavior in actual working conditions during actual tests.

[0067] like Figure 4 and Figure 5 As shown, since the insulated gate bipolar transistor T1, the anti-parallel diode D1 and the insulated gate bipolar transistor T2 are key components involved in the through discharge path in this working condition, complete components are required to achieve normal discharge function, and an insulating block can be used as a replacement. The use of insulating blocks can effectively block the current path at these locations. In actual tests, the performance and stability of other parts of the entire circuit or module can be observed and evaluated in the absence of these key components.

[0068] in, Figure 4 and Figure 5 The insulated gate bipolar transistors T3 and T4, the anti-parallel diodes D3 and D4, and the capacitor C are devices whose affected degree is less than the preset degree threshold, and it is not necessary to replace other devices.

[0069] According to the alternative method of the above example, it can not only meet the different simulation requirements for key components and non-key components in the test but also reduce the test cost, and at the same time, it can accurately reflect the circuit conditions in actual working conditions during the experiment.

[0070] In one embodiment, the method may further include: when it is determined that the target replacement component is a metal block, determining the length and cross-sectional area of ​​the metal block based on the test voltage and test current of the device to be replaced.

[0071] Exemplarily, the resistance is determined based on the ratio between the test voltage and the test current of the device to be replaced, so that the approximate resistance value of the metal block can be determined.

[0072] Exemplarily, the cross-sectional area of ​​the metal block can be determined based on the test current of the device to be replaced and the conductivity of the metal block. For example, taking 3 times the test current as a reference, multiplying it by the conductivity of the metal block to obtain the product between the length and the cross-sectional area of ​​the metal block, and using the product to determine the length and the cross-sectional area of ​​the metal block.

[0073] According to the above embodiment, when the target replacement device is determined to be a metal block, the length and cross-sectional area of ​​the metal block can be accurately determined based on the test voltage and test current of the device to be replaced, thereby improving the accuracy of the test.

[0074] In one embodiment, the above method may also include: measuring the maximum overvoltage value of the lower bridge arm in the first test circuit while controlling the bypass switch in the first test circuit to be closed; determining the first test voltage based on the maximum overvoltage value of the lower bridge arm; performing a simulation test on the second test circuit based on the first test voltage to obtain the breakdown voltage of the target turning thyristor and the withstand voltage of each insulated gate bipolar transistor in the second test circuit; adjusting the first test voltage based on the breakdown voltage of the target turning thyristor in the second test circuit and the withstand voltage of each insulated gate bipolar transistor to obtain the target test voltage of the second test circuit.

[0075] Exemplarily, the target test voltage is greater than the first test voltage and less than the withstand voltage. If the breakdown voltage is between the first test voltage and the withstand voltage, the breakdown voltage is used as the target test voltage.

[0076] Exemplarily, the breakdown voltage is a positive bias value of a breakdown action center of a target transition thyristor.

[0077] Illustratively, the withstand voltage is the maximum voltage that an insulated gate bipolar transistor can withstand.

[0078] Exemplarily, the maximum overvoltage value of the lower bridge arm is the first test voltage.

[0079] Exemplarily, the voltage is gradually increased starting from the first test voltage, and a simulation test is performed on the second test circuit, so as to obtain the breakdown voltage of the target transition thyristor and the withstand voltage of each insulated gate bipolar transistor in the second test circuit.

[0080] According to the above implementation, the maximum overvoltage value of the lower bridge arm is first determined, and the first test voltage is used as the initial test voltage, so that the test speed can be accelerated, and the breakdown voltage of the target turning thyristor and the withstand voltage of each insulated gate bipolar transistor can be quickly obtained. Then, the target test voltage of the second test circuit can be quickly obtained later.

[0081] In actual tests, testing with this target test voltage can fully and realistically simulate extreme working conditions, detect the protection performance of the full-bridge module, ensure its reliability in the flexible DC transmission system, and avoid irreversible damage to the device.

[0082] Among them, setting the test voltage higher than the maximum value when the lower bridge arm is over-voltaged can simulate a situation worse than the actual fault. During the operation of the flexible DC transmission system, a fault in the station will cause the bridge arm to over-voltaged. Testing with a voltage higher than the maximum value of this over-voltaged can fully test the protection capability of the full-bridge submodule under extreme over-voltage, discover potential problems in advance, and ensure that the full-bridge module can also have a certain ability to cope with the most serious actual faults, thereby ensuring system safety. For example, when the actual fault occurs, the maximum value of the bridge arm over-voltaged is a certain value, and the test voltage is higher, which can test whether the full-bridge module will be damaged under such extreme conditions, and whether its protection mechanism can be effectively activated.

[0083] In addition, the effectiveness of the protection mechanism of the full-bridge module can be verified by setting the test voltage according to the forward bias value of the breakdown action center of the turning thyristor or active clamp configured in the full-bridge module. The turning thyristor and active clamp are the key parts of the full-bridge module protection. The forward bias value of the breakdown action center is used as the test voltage. When the voltage reaches this value, the protection mechanism should be activated. By observing the state of the full-bridge module at this time, it can be judged whether the protection function is normal, and then the reliability of the full-bridge module can be evaluated. In the test, if the voltage reaches the forward bias value of the breakdown action center of the turning thyristor or active clamp, the full-bridge module can start the protection in time to limit the development of the fault, which means that the protection mechanism is effective.

[0084] Moreover, limiting the test voltage to within the tolerance voltage range of the IGBT power device can avoid irreversible damage to the device during the test. If the test voltage is too high, for example, exceeding the tolerance value of the IGBT, the device will be directly damaged, and the protection performance of the full-bridge module cannot be accurately evaluated, which is not conducive to subsequent analysis and improvement. Therefore, ensuring that the test voltage is within a safe range can not only complete the test of the full-bridge module, but also ensure that the device can be reused, improving the test efficiency and economy.

[0085] In one embodiment, it also includes: based on the target test voltage, performing a simulation test on the second test circuit to obtain the voltage rise rate of each insulated gate bipolar transistor in the second test circuit; when the voltage rise rate of each insulated gate bipolar transistor in the second test circuit does not meet the preset voltage rise condition, setting a thyristor trigger module for the target turning thyristor in the second test circuit to obtain a third test circuit, wherein the thyristor trigger module is used to detect the operating voltage of each insulated gate bipolar transistor in the second test circuit, and trigger the target turning thyristor to turn on when the operating voltage is greater than a preset voltage threshold.

[0086] Exemplarily, the control end of the thyristor trigger module is connected to the controlled end of the target turning thyristor, and the detection end of the thyristor trigger module is used to be connected in parallel with each insulated gate bipolar transistor to detect the operating voltage of each insulated gate bipolar transistor. When the thyristor trigger module detects that the operating voltage of any insulated gate bipolar transistor is greater than a preset voltage threshold, a trigger signal is provided through the control end of the thyristor trigger module to trigger the target turning thyristor to conduct. The trigger signal can be a voltage signal.

[0087] Exemplarily, the voltage rising condition may be that a voltage rising rate of any insulated gate bipolar transistor is greater than a preset threshold.

[0088] Exemplarily, when the through-discharge test is performed on the second test circuit, the voltage rising rate of the insulated gate bipolar transistor can be detected.

[0089] In this example, when the third test circuit is used for actual testing, when the voltage rises too fast, the circuit can trigger the transition thyristor at the appropriate time to avoid triggering the transition thyristor too early or too late, thereby accurately and smoothly guiding the current and preventing the device from being subjected to excessively high instantaneous voltage shocks.

[0090] According to the above example, when testing the full-bridge module of the device that does not have the long-term failure current-carrying capacity, triggering the through discharge can detect the protection effect of the turning thyristor. When the third test circuit detects that the abnormal voltage or current is close to the dangerous threshold, the triggering moment of the turning thyristor is accurately controlled to avoid inaccurate test results or unnecessary damage to the device due to too early or too late triggering.

[0091] After obtaining the second or third test circuit, the bypass switch refusal test and the upper and lower bridge arm direct short circuit test can be performed, so as to adjust the test circuit according to the actual test results to obtain a target full-bridge module that meets the requirements.

[0092] Figure 6 It is a structural block diagram of a test circuit design device for a flexible DC converter valve full-bridge module according to an embodiment of the present invention.

[0093] like Figure 6 As shown, the test circuit design device of the flexible DC converter valve full-bridge module may include:

[0094] A first circuit determination module 610 is used to connect each of the insulated gate bipolar transistors in the full-bridge module in parallel with a bypass switch to obtain a first test circuit when the device attribute of each of the insulated gate bipolar transistors in the full-bridge module is a device with long-term failure current-carrying capability;

[0095] A first control module 620, configured to control each of the insulated gate bipolar transistors to be turned on in the first test circuit, and to gradually increase the on-current of each of the insulated gate bipolar transistors to a first target current;

[0096] a second control module 630, configured to control the bypass switch in the first test circuit to close when the duration of the on-current of each of the insulated gate bipolar transistors in the first test circuit reaching the first target current is greater than a first time threshold, and to measure the test voltage and the test current of each of the insulated gate bipolar transistors in the first test circuit to obtain a voltage change curve and a current change curve of each of the insulated gate bipolar transistors;

[0097] A thyristor determination module 640, configured to determine a target turning thyristor based on the voltage change curve and the current change curve when the voltage change curve of any of the insulated gate bipolar transistors does not meet a preset voltage change condition;

[0098] The second circuit determination module 650 is used to connect the insulated gate bipolar transistor in the full-bridge module in parallel with the target turning thyristor to obtain a second test circuit for the full-bridge module.

[0099] In one implementation, the thyristor determination module 640 includes:

[0100] an attribute updating unit, configured to update the device attribute of the first insulated gate bipolar transistor to a device without long-term failure current-carrying capability when the continuous time of the voltage in the first interval in the voltage variation curve of the first insulated gate bipolar transistor is less than a second time threshold;

[0101] a device voltage determination unit, configured to determine a forward breakover voltage of the target breakover thyristor based on an average voltage of the voltage variation curve in a non-first interval;

[0102] The device current determining unit is used to determine the rated current of the target transition thyristor based on the average current of the current variation curve in the first interval.

[0103] In one embodiment, the above method may further include:

[0104] A data measurement module, used to measure the test voltage and test current of each diode in the first test circuit under the condition of controlling the bypass switch in the first test circuit to be closed;

[0105] A first degree determination module, configured to determine the degree of influence of each of the insulated gate bipolar transistors based on a test voltage and a test current of each of the insulated gate bipolar transistors;

[0106] A second degree determination module, configured to determine the degree of influence of each diode based on a test voltage and a test current of each diode;

[0107] A device-to-be-replaced determining module, configured to determine a device to be replaced among each of the insulated gate bipolar transistors and each of the diodes based on the degree of influence of each of the insulated gate bipolar transistors and the degree of influence of each of the diodes;

[0108] A target device determination module, configured to determine a target replacement device based on the degree of impact of the device to be replaced;

[0109] A device replacement module is used to replace the device to be replaced with the target replacement device in the second test circuit.

[0110] In one implementation, the target device determination module includes:

[0111] an insulating block determining unit, configured to determine that the target replacement component is an insulating block when the impact degree of the component to be replaced is greater than a first degree threshold;

[0112] a metal block determining unit, configured to determine that the target replacement component is a metal block when the impact degree of the component to be replaced is less than the first degree threshold and greater than a second degree threshold;

[0113] The first degree threshold is greater than the second degree threshold.

[0114] In one implementation, the target device determination module further includes:

[0115] The metal block parameter determination unit is used to determine the length and cross-sectional area of ​​the metal block based on the test voltage and test current of the device to be replaced when it is determined that the target replacement device is a metal block.

[0116] In one embodiment, the above device further comprises:

[0117] an overvoltage value determination module, configured to measure a maximum overvoltage value of a lower bridge arm in the first test circuit while controlling the bypass switch in the first test circuit to be closed;

[0118] A first voltage determination module, used for determining a first test voltage based on the maximum overvoltage value of the lower bridge arm;

[0119] A first simulation test module, configured to perform a simulation test on the second test circuit based on the first test voltage to obtain a breakdown voltage of the target thyristor and a withstand voltage of each of the insulated gate bipolar transistors in the second test circuit;

[0120] The second voltage determination module is used to adjust the first test voltage based on the breakdown voltage of the target transition thyristor in the second test circuit and the withstand voltage of each of the insulated gate bipolar transistors to obtain a target test voltage of the second test circuit.

[0121] In one embodiment, the above device further comprises:

[0122] A second simulation test module, configured to perform a simulation test on the second test circuit based on the target test voltage to obtain a voltage rise rate of each of the insulated gate bipolar transistors in the second test circuit;

[0123] The third test circuit determination module is used to set a thyristor trigger module for the target turning thyristor in the second test circuit when the voltage rise rate of each of the insulated gate bipolar transistors in the second test circuit does not meet the preset voltage rise condition, so as to obtain a third test circuit, wherein the thyristor trigger module is used to detect the operating voltage of each of the insulated gate bipolar transistors in the second test circuit, and trigger the target turning thyristor to turn on when the operating voltage is greater than a preset voltage threshold.

[0124] For the description of specific functions and examples of each module and submodule of the system in the embodiment of the present invention, reference can be made to the relevant description of the corresponding steps in the above method embodiment, which will not be repeated here.

[0125] In the technical solution of the present invention, the acquisition, storage and application of user personal information involved are in compliance with the provisions of relevant laws and regulations and do not violate public order and good morals.

[0126] According to an embodiment of the present invention, the present invention also provides a system and a readable storage medium.

[0127] Figure 7A schematic block diagram of an example electronic device 800 that can be used to implement an embodiment of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital assistants, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0128] like Figure 7 As shown, the device 800 includes a computing unit 801, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 802 or a computer program loaded from a storage unit 808 to a random access memory (RAM) 803. In the RAM 803, various programs and data required for the operation of the device 800 can also be stored. The computing unit 801, the ROM 802, and the RAM 803 are connected to each other via a bus 804. An input / output (I / O) interface 805 is also connected to the bus 804.

[0129] A number of components in the device 800 are connected to the I / O interface 805, including: an input unit 806, such as a keyboard, a mouse, etc.; an output unit 807, such as various types of displays, speakers, etc.; a storage unit 808, such as a disk, an optical disk, etc.; and a communication unit 809, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 809 allows the device 800 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0130] The computing unit 801 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 801 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The computing unit 801 performs the various methods and processes described above, such as the test circuit design method for the flexible DC converter valve full-bridge module. For example, in some embodiments, the test circuit design method for the flexible DC converter valve full-bridge module may be implemented as a computer software program, which is tangibly contained in a machine-readable medium, such as a storage unit 808. In some embodiments, part or all of the computer program may be loaded and / or installed on the device 800 via the ROM 802 and / or the communication unit 809. When the computer program is loaded into the RAM 803 and executed by the computing unit 801, one or more steps of the test circuit design method for the flexible DC converter valve full-bridge module described above may be executed. Alternatively, in other embodiments, the calculation unit 801 may be configured to execute the test circuit design method for the flexible DC converter valve full-bridge module in any other appropriate manner (for example, by means of firmware).

[0131] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0132] The program code for implementing the method of the present invention can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer or other programmable data processing device, so that the program code, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The program code can be executed entirely on the machine, partially on the machine, partially on the machine as a stand-alone software package and partially on a remote machine, or entirely on a remote machine or server.

[0133] In the context of the present invention, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or equipment, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0134] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0135] The systems and techniques described herein may be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), and the Internet.

[0136] A computer system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The relationship of client and server is generated by computer programs running on respective computers and having a client-server relationship with each other. The server may be a cloud server, a server of a distributed system, or a server combined with a blockchain.

[0137] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this document does not limit this.

[0138] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A test circuit design method for a flexible DC converter valve full-bridge module, characterized in that: include: When the device property of each insulated gate bipolar transistor in the full-bridge module is a device with long-term failure current-carrying capability, each of the insulated gate bipolar transistors in the full-bridge module is connected in parallel with a bypass switch to obtain a first test circuit; In the first test circuit, each of the insulated gate bipolar transistors is controlled to be turned on, and the on-current of each of the insulated gate bipolar transistors is gradually increased to a first target current; When the duration of the on-state current of each of the insulated gate bipolar transistors in the first test circuit reaching the first target current is greater than a first time threshold, controlling the bypass switch in the first test circuit to close, and measuring the test voltage and the test current of each of the insulated gate bipolar transistors in the first test circuit to obtain a voltage change curve and a current change curve of each of the insulated gate bipolar transistors; When the continuous time of the voltage in the first interval in the voltage variation curve of the first insulated gate bipolar transistor is less than the second time threshold, updating the device attribute of the first insulated gate bipolar transistor to a device without long-term failure current-carrying capability; Based on the average voltage of the voltage variation curve in the non-first interval, determine Target turning thyristor forward turning voltage; Determining a rated current of the target turning thyristor based on an average current of the current variation curve in the first interval; The insulated gate bipolar transistor in the full-bridge module is connected in parallel with the target turning thyristor to obtain a second test circuit for the full-bridge module.

2. The method according to claim 1, characterized in that Also includes: Under the condition that the bypass switch in the first test circuit is controlled to be closed, measuring the test voltage and the test current of each diode in the first test circuit; Determining the degree of influence of each of the insulated gate bipolar transistors based on the test voltage and the test current of each of the insulated gate bipolar transistors; Determining the degree of influence of each of the diodes based on the test voltage and the test current of each of the diodes; Determining a device to be replaced in each of the insulated gate bipolar transistors and each of the diodes based on the degree of influence of each of the insulated gate bipolar transistors and the degree of influence of each of the diodes; Determining a target replacement component based on the impact degree of the component to be replaced; In the second test circuit, the device to be replaced is replaced with the target replacement device.

3. The method according to claim 2, characterized in that The step of determining a target replacement component based on the degree of impact of the component to be replaced includes: In a case where the degree of influence of the to-be-replaced component is greater than a first degree threshold, determining that the target replacement component is an insulating block; In a case where the impact degree of the to-be-replaced component is less than the first degree threshold and greater than the second degree threshold, determining that the target replacement component is a metal block; The first degree threshold is greater than the second degree threshold.

4. The method according to claim 3, characterized in that: Also includes: In the case where the target replacement component is determined to be a metal block, the length and cross-sectional area of ​​the metal block are determined based on the test voltage and test current of the device to be replaced.

5. The method according to any one of claims 1 to 4, characterized in that Also includes: Under the condition that the bypass switch in the first test circuit is controlled to be closed, measuring the maximum overvoltage value of the lower bridge arm in the first test circuit; Determining a first test voltage based on the maximum overvoltage value of the lower bridge arm; Based on the first test voltage, a simulation test is performed on the second test circuit to obtain the breakdown voltage of the target thyristor and the withstand voltage of each of the insulated gate bipolar transistors in the second test circuit; Based on the breakdown voltage of the target thyristor in the second test circuit and the withstand voltage of each of the insulated gate bipolar transistors, the first test voltage is adjusted to obtain a target test voltage of the second test circuit.

6. The method according to claim 5, characterized in that Also includes: Based on the target test voltage, a simulation test is performed on the second test circuit to obtain a voltage rise rate of each of the insulated gate bipolar transistors in the second test circuit; When the voltage rise rate of each of the insulated gate bipolar transistors in the second test circuit does not meet the preset voltage rise condition, a thyristor trigger module is set for the target transition thyristor in the second test circuit to obtain a third test circuit, wherein the thyristor trigger module is used to detect the operating voltage of each of the insulated gate bipolar transistors in the second test circuit, and trigger the target transition thyristor to turn on when the operating voltage is greater than a preset voltage threshold.

7. A test circuit design device for a flexible DC converter valve full-bridge module, comprising: A first circuit determination module is used to connect each of the insulated gate bipolar transistors in the full-bridge module in parallel with a bypass switch to obtain a first test circuit when the device attribute of each of the insulated gate bipolar transistors in the full-bridge module is a device with long-term failure current-carrying capacity; A first control module, used for controlling each of the insulated gate bipolar transistors to be turned on in the first test circuit, and gradually increasing the on-current of each of the insulated gate bipolar transistors to a first target current; a second control module, configured to control the bypass switch in the first test circuit to close when the duration of the on-current of each of the insulated gate bipolar transistors in the first test circuit reaching the first target current is greater than a first time threshold, and to measure the test voltage and the test current of each of the insulated gate bipolar transistors in the first test circuit to obtain a voltage change curve and a current change curve of each of the insulated gate bipolar transistors; A thyristor determination module, configured to determine a target turning thyristor based on the voltage change curve and the current change curve when the voltage change curve of any of the insulated gate bipolar transistors does not meet a preset voltage change condition; A second circuit determination module is used to connect the insulated gate bipolar transistor in the full-bridge module in parallel with the target turning thyristor to obtain a second test circuit for the full-bridge module; Wherein, the thyristor determination module comprises: an attribute updating unit, configured to update the device attribute of the first insulated gate bipolar transistor to a device without long-term failure current-carrying capability when the continuous time of the voltage in the first interval in the voltage variation curve of the first insulated gate bipolar transistor is less than a second time threshold; a device voltage determination unit, configured to determine a forward breakover voltage of the target breakover thyristor based on an average voltage of the voltage variation curve in a non-first interval; The device current determining unit is used to determine the rated current of the target transition thyristor based on the average current of the current variation curve in the first interval.

8. A test circuit design system for a flexible DC converter valve full-bridge module, comprising: at least one processor; as well as a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 6.

9. A non-transitory computer-readable storage medium storing computer instructions, wherein: The computer instructions are used to cause the computer to execute the method according to any one of claims 1-6.

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