IGBT device short-circuit test method and device

Abstract

The present invention provides a short-circuit test method and apparatus for an IGBT device. The apparatus comprises: a busbar capacitor recharge circuit, a short-circuit test main circuit, a bridge arm current generating circuit, a drive circuit, and a data acquisition circuit. The busbar capacitor recharge circuit has its two terminals connected to the positive and negative poles of an external DC power supply, and is also connected in parallel to the short-circuit test main circuit. The bridge arm current generating circuit has its two terminals connected to the positive and negative poles of an external DC power supply, and is also connected to the short-circuit test main circuit. The drive circuit is connected to the short-circuit test main circuit. The data acquisition circuit is respectively connected to the short-circuit test main circuit and the bridge arm current generating circuit. The implementation of the present invention provides important guidance for the localization research and development of converter valves and their engineering applications.

Description

Technical Field

[0001] The present invention relates to the field of flexible direct current transmission and semiconductor device testing, and in particular to an IGBT device short-circuit test method and device. Background Art

[0002] MMC valves are the core equipment of Flexible DC transmission technology. VSC-HVDC (Voltage Source Converter-based High Voltage Direct Current) is a new type of DC transmission system based on voltage source converters. Compared to traditional DC transmission, VSC-HVDC requires less reactive power compensation and, due to its fully controlled components, eliminates commutation failures. It can power passive systems and independently regulate active and reactive power. It holds broad application prospects in areas such as asynchronous grid interconnection, renewable energy integration, and weak grid power supply.

[0003] The core component of the MMC flexible converter valve is the IGBT. The reliability of the IGBT is crucial to the stable operation of the MMC flexible converter valve. Transient overcurrent conditions in the MMC flexible converter valve subject the IGBT to severe voltage and current stresses. IGBTs are highly susceptible to irreversible damage in short-circuit conditions, thus impacting the stability of the MMC flexible direct current converter valve. The short-circuit process of a submodule IGBT short-circuit is extremely severe, with the short-circuit current reaching approximately 10 times that of normal operating conditions. Therefore, research on the stress and failure of IGBTs in converter valves with submodule IGBT short-circuit transient conditions plays a crucial role in guiding the domestic development and engineering application of converter valves. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect in the prior art that it is difficult to test the stress and failure of the transient working conditions of the IGBT device of the converter valve with a sub-module IGBT direct short circuit, thereby providing an IGBT device short circuit test method and device.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] In the first aspect, an embodiment of the present invention provides an IGBT device short-circuit test device, comprising: a bus capacitor energy compensation circuit, a short-circuit test main circuit, a bridge arm current generating circuit, a drive circuit and a data acquisition circuit, wherein the two ends of the bus capacitor energy compensation circuit are correspondingly connected to the positive and negative poles of an external DC power supply, and the bus capacitor energy compensation circuit is also connected in parallel with the short-circuit test main circuit; the two ends of the bridge arm current generating circuit are correspondingly connected to the positive and negative poles of the external DC power supply, and the bridge arm current generating circuit is also connected to the short-circuit test main circuit; the drive circuit is connected to the short-circuit test main circuit; and the data acquisition circuit is respectively connected to the short-circuit test main circuit and the bridge arm current generating circuit.

[0007] Preferably, the short-circuit test main circuit includes: a first device under test, a second device under test, a first diode, a second diode, an auxiliary device and a first protective device, wherein the first device under test is connected in reverse parallel with the first diode, and the second device under test is connected in reverse parallel with the second diode; the first end of the first device under test is connected to one end of the bus capacitor energy compensation circuit through the first protective device, the second end of the first device under test is respectively connected to the first end of the second device under test, the first end of the auxiliary device and the bridge arm current generating circuit, and the control end of the first device under test is connected to the drive circuit; the control end of the second device under test is connected to the drive circuit, and the second end of the second device under test and the second end of the auxiliary device are both grounded.

[0008] Preferably, the bus capacitor energy compensation circuit includes: a first capacitor, a first resistor, a second resistor, a first controllable device and a second controllable device, wherein the positive electrode of the first capacitor is respectively connected to one end of the second resistor, the first end of the first controllable device and the first end of the first protection device, and the negative electrode of the first capacitor is connected to the negative electrode of the external DC power supply and then grounded; the other end of the second resistor is connected to the negative electrode of the first capacitor through the second controllable device; and the second end of the first controllable device is connected to the positive electrode of the external DC power supply through the first resistor.

[0009] Preferably, the bridge arm current generating circuit includes: a bridge arm current inductor, a load capacitor energy compensation circuit and a freewheeling loop, wherein one end of the bridge arm current inductor is respectively connected to the second end of the first device under test, the first end of the second device under test and the first end of the auxiliary device, and the other end of the bridge arm current inductor is connected to the load capacitor energy compensation circuit; the two ends of the load capacitor energy compensation circuit are correspondingly connected to the positive and negative poles of the external DC power supply; and the freewheeling loop is connected in parallel with the bridge arm current inductor.

[0010] Preferably, the load capacitance energy compensation circuit includes: a second capacitor, a third resistor, a fourth resistor, a third controllable device, a fourth controllable device and a second protection device, wherein the positive electrode of the second capacitor is respectively connected to one end of the third resistor, one end of the fourth resistor and the first end of the second protection device, and the negative electrode of the second capacitor is connected to the negative electrode of the external DC power supply and then grounded; the second end of the second protection device is connected to the other end of the bridge arm current inductor; the other end of the fourth resistor is connected to the negative electrode of the second capacitor through the fourth controllable device; and the other end of the third resistor is connected to the positive electrode of the external DC power supply through the third controllable device.

[0011] Preferably, the data acquisition circuit includes: a first high-voltage voltage measuring probe, a second high-voltage voltage measuring probe, a low-voltage differential active voltage measuring probe, a low-voltage passive voltage measuring probe, a first drive current measuring device, a second drive current measuring device, a short-circuit current measuring device and a bridge arm current measuring device, wherein,

[0012] The first high-voltage voltage measuring probe is connected to the first end of the second device under test; the second high-voltage voltage measuring probe is connected to the first end of the first device under test; the low-voltage differential active voltage measuring probe is connected to the control end of the first device under test; the low-voltage passive voltage measuring probe is connected to the control end of the second device under test; the first drive current measuring device is installed on the drive wiring piece connected to the first device under test in the drive circuit; the second drive current measuring device is installed on the drive wiring piece connected to the second device under test in the drive circuit; the short-circuit current measuring device is installed on the second end of the second device under test; and the bridge arm current measuring device is installed on the circuit installed in the bridge arm current generating circuit.

[0013] In the second aspect, an embodiment of the present invention provides an IGBT device short-circuit test method, based on the IGBT device short-circuit test apparatus described in the first aspect of the embodiment of the present invention, the IGBT device short-circuit test method includes: establishing a bus voltage of a sub-module of the device to be tested; establishing a bridge arm current of the sub-module of the device to be tested according to preset experimental requirements, the preset experiments include a first type of short-circuit experiment, a second type of short-circuit experiment and a third type of short-circuit experiment; controlling a driving circuit to generate a pulse signal according to the preset experimental requirements, and controlling the corresponding device to be tested to connect to a short-circuit test main circuit for a short-circuit experiment according to the pulse signal; obtaining experimental data collected by a data acquisition circuit, and evaluating the reliability of the device to be tested based on the experimental data.

[0014] Preferably, when performing a first type of short-circuit test, the corresponding device under test is controlled according to the pulse signal to connect to the short-circuit test main circuit to perform a short-circuit test, including: bypassing the first device under test and disconnecting the bridge arm current inductance; turning on the first controllable device and charging the first capacitor to a first preset voltage; triggering the second device under test to turn on, and the second device under test undergoes a first type of short circuit.

[0015] Preferably, when conducting a second type of short-circuit test, the corresponding device under test is controlled according to the pulse signal to connect to the short-circuit test main circuit to conduct a short-circuit test, including: disconnecting the second device under test; turning on the first controllable device to charge the first capacitor to a second preset voltage; turning on the third controllable device to charge the second capacitor to a third preset voltage; using the first capacitor and the second capacitor to establish a bridge arm current flowing out of the sub-module; turning on the first device under test and the auxiliary device, and a second type of short circuit occurs under the first device under test.

[0016] Preferably, when performing a third type of short-circuit test, the corresponding device under test is controlled according to the pulse signal to connect to the short-circuit test main circuit to perform a short-circuit test, including: disconnecting the second device under test; turning on the first controllable device to charge the first capacitor to a fourth preset voltage; turning on the third controllable device to charge the second capacitor to a fifth preset voltage; using the second capacitor to establish a bridge arm current flowing in the direction of the sub-module; turning on the first device under test and the auxiliary device, and the first device under test undergoes a third type of short circuit.

[0017] The technical solution of the present invention has the following advantages:

[0018] The IGBT device short-circuit test device provided by the present invention includes: a busbar capacitor energy-replenishing circuit, a short-circuit test main circuit, a bridge arm current generating circuit, a drive circuit, and a data acquisition circuit. The busbar capacitor energy-replenishing circuit has its two ends connected to the positive and negative poles of an external DC power supply, and the busbar capacitor energy-replenishing circuit is also connected in parallel to the short-circuit test main circuit; the bridge arm current generating circuit has its two ends connected to the positive and negative poles of the external DC power supply, and the bridge arm current generating circuit is also connected to the short-circuit test main circuit; the drive circuit is connected to the short-circuit test main circuit; and the data acquisition circuit is respectively connected to the short-circuit test main circuit and the bridge arm current generating circuit. The IGBT device short-circuit test device is used to simulate a submodule direct-through short-circuit operating condition with the influence of bridge arm current, providing a short-circuit test platform for IGBT devices. This can be used to study the stress and failure of IGBT devices in converter valves under transient operating conditions with direct-through short-circuit of the submodule IGBT, providing important guidance for the localization research and development of converter valves and their engineering applications.

[0019] The IGBT device short-circuit test method provided by the present invention includes: establishing a bus voltage of a submodule of the device to be tested; establishing a bridge arm current of the submodule of the device to be tested according to preset experimental requirements, wherein the preset experiments include a first type of short-circuit test, a second type of short-circuit test, and a third type of short-circuit test; controlling a drive circuit to generate a pulse signal according to the preset experimental requirements, and controlling the corresponding device to be tested to connect to a short-circuit test main circuit to perform a short-circuit test according to the pulse signal; obtaining experimental data collected by a data acquisition circuit, and evaluating the reliability of the device to be tested based on the experimental data. By equivalently treating a submodule direct short-circuit condition with the influence of the bridge arm current, a short-circuit test environment is provided for the IGBT device. Three types of IGBT standard short-circuit tests can be performed on the IGBT device of a converter valve with a submodule IGBT direct short-circuit, which plays an important guiding role in the domestic development and engineering application of converter valves. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 This is a principle block diagram of a specific example of an IGBT device short-circuit test device according to an embodiment of the present invention;

[0022] Figure 2 A circuit diagram of a specific example of an IGBT device short-circuit test device according to an embodiment of the present invention;

[0023] Figure 3 The flowchart is a specific example of the IGBT device short-circuit test method in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0025] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components; wireless connections or wired connections. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0027] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] like Figure 1 As shown, an embodiment of the present invention provides an IGBT device short-circuit test device, including: a bus capacitor energy compensation circuit 1, a short-circuit test main circuit 2, a bridge arm current generating circuit 3, a drive circuit 4 and a data acquisition circuit 5, wherein the two ends of the bus capacitor energy compensation circuit 1 are correspondingly connected to the positive and negative poles of the external DC power supply, and the bus capacitor energy compensation circuit 1 is also connected in parallel with the short-circuit test main circuit 2; the two ends of the bridge arm current generating circuit 3 are correspondingly connected to the positive and negative poles of the external DC power supply, and the bridge arm current generating circuit 3 is also connected to the short-circuit test main circuit 2; the drive circuit 4 is connected to the short-circuit test main circuit 2; and the data acquisition circuit 5 is respectively connected to the short-circuit test main circuit 2 and the bridge arm current generating circuit 3.

[0029] In one specific embodiment, the circuit structure of the IGBT device short-circuit test device adopts the same circuit structure as the submodule, using an equivalent MMC converter valve submodule direct short-circuit operating condition to simulate the actual operating environment of the device under test in an experimental environment. Specifically, the busbar capacitor energy compensation circuit 1 is used in conjunction with an external DC power supply to generate the submodule busbar voltage. The busbar capacitor energy compensation circuit 1, the bridge arm current generation circuit 3, and the external DC power supply are used in conjunction to generate the bridge arm current. Therefore, the above-mentioned submodule busbar voltage and bridge arm current are used as the key stresses in the direct short-circuit operating condition of the device under test.

[0030] Furthermore, based on the stress, the driver circuit 4 is used to control the DUT to conduct in sequence, thereby triggering a short circuit in the DUT and performing a short circuit test. The data acquisition circuit 5 then collects experimental data during the short circuit test, and the stability of the DUT is evaluated based on the experimental data.

[0031] The IGBT device short-circuit test device provided by the present invention includes: a busbar capacitor energy-replenishing circuit, a short-circuit test main circuit, a bridge arm current generating circuit, a drive circuit, and a data acquisition circuit. The busbar capacitor energy-replenishing circuit has its two ends connected to the positive and negative poles of an external DC power supply, and the busbar capacitor energy-replenishing circuit is also connected in parallel to the short-circuit test main circuit; the bridge arm current generating circuit has its two ends connected to the positive and negative poles of the external DC power supply, and the bridge arm current generating circuit is also connected to the short-circuit test main circuit; the drive circuit is connected to the short-circuit test main circuit; and the data acquisition circuit is respectively connected to the short-circuit test main circuit and the bridge arm current generating circuit. The IGBT device short-circuit test device is used to simulate a submodule direct-through short-circuit operating condition with the influence of bridge arm current, providing a short-circuit test platform for IGBT devices. This can be used to study the stress and failure of IGBT devices in converter valves under transient operating conditions with direct-through short-circuit of the submodule IGBT, providing important guidance for the localization research and development of converter valves and their engineering applications.

[0032] In one embodiment, if Figure 2 As shown, the short-circuit test main circuit 2 includes: a first device under test T1, a second device under test T2, a first diode D1, a second diode D2, an auxiliary device T3 and a first protection device T4, wherein the first device under test T1 is connected in reverse parallel to the first diode D1, and the second device under test T2 is connected in reverse parallel to the second diode D2; the first end of the first device under test T1 is connected to one end of the bus capacitor energy compensation circuit 1 through the first protection device T4, the second end of the first device under test T1 is respectively connected to the first end of the second device under test T2, the first end of the auxiliary device T3 and the bridge arm current generating circuit 3, the control end of the first device under test T1 is connected to the drive circuit 4; the control end of the second device under test T2 is connected to the drive circuit 4, and the second end of the second device under test T2 and the second end of the auxiliary device T3 are both grounded.

[0033] In one specific embodiment, the first device under test (DUT) T1 is a top-side IGBT device (IGBT) T1. The second device under test (DUT) T2 is a bottom-side IGBT device (IGBT) T2. The top-side IGBT device (IGBT) T1, the bottom-side IGBT device (IGBT) T2, and the anti-parallel diodes (D1 and D2) are connected to the short-circuit test main circuit via a dedicated test socket. Using the test socket to connect the DUT to the circuit board facilitates replacement of the DUT.

[0034] Furthermore, auxiliary device T3 is an IGBT device with a high current shutoff capability. Using auxiliary device T3 can perform standard tests for Class I, Class II, and Class III short circuits on the IGBT under test. During the short-circuit test, driver circuit 4 controls the upper IGBT under test device T1 and the lower IGBT under test device T2 to conduct sequentially, triggering a short circuit in the upper IGBT under test device T1 and the lower IGBT under test device T2.

[0035] In an embodiment of the present invention, the first protection device T4 is an IGBT. A busbar protection IGBT (T4) is connected between the upper IGBT under test (T1) and the positive electrode of the busbar capacitor (C1). If the upper IGBT under test is damaged and cannot be shut down normally, the busbar protection IGBT can shut off the short-circuit current, thereby protecting the experimental platform.

[0036] In one embodiment, if Figure 2 As shown, the bus capacitor energy compensation circuit 1 includes: a first capacitor C1, a first resistor R1, a second resistor R2, a first controllable device T7 and a second controllable device T8, wherein the positive electrode of the first capacitor C1 is respectively connected to one end of the second resistor R2, the first end of the first controllable device T7 and the first end of the first protection device T4, and the negative electrode of the first capacitor C1 is connected to the negative electrode of the external DC power supply and then grounded; the other end of the second resistor R2 is connected to the negative electrode of the first capacitor C1 through the second controllable device T8; the second end of the first controllable device T7 is connected to the positive electrode of the external DC power supply through the first resistor R1.

[0037] In one specific embodiment, the first resistor R1 and the second resistor R2 are power resistors used to limit the charging and discharging speeds of the capacitor. The first controllable device T7 is a charging IGBT, and the second controllable device T8 is a discharging IGBT. The control terminals of the first and second controllable devices T7 and T8 are connected to an external remote control device. The external remote control device controls the charging and discharging of the first capacitor C1 by turning the charging and discharging IGBTs on and off.

[0038] Specifically, when charging the first capacitor C1, the external DC power supply is first adjusted to the required voltage value. The external remote control device then sends a pulse signal to control the first controllable device T7 to turn on. The external DC power supply charges the first capacitor C1 to the required voltage of the experiment through the diode D4, the power resistor R1, and the first controllable device T7. When discharging the first capacitor C1, the external remote control device sends a pulse signal to control the second controllable device T8 to turn on. The first capacitor C1 is discharged through the power resistor R2 and the second controllable device T8. During the experiment, the charging and discharging of each capacitor is remotely controlled to ensure personnel safety.

[0039] In one embodiment, if Figure 2As shown, the bridge arm current generating circuit 3 includes: a bridge arm current inductor L1, a load capacitor energy compensation circuit 31 and a freewheeling loop 32, wherein one end of the bridge arm current inductor L1 is respectively connected to the second end of the first device under test T1, the first end of the second device under test T2 and the first end of the auxiliary device T3, and the other end of the bridge arm current inductor L1 is connected to the load capacitor energy compensation circuit 31; the two ends of the load capacitor energy compensation circuit 31 are correspondingly connected to the positive and negative poles of the external DC power supply; and the freewheeling loop 32 is connected in parallel with the bridge arm current inductor L1.

[0040] In a specific embodiment, the bridge arm current inductor L1 is installed in an electromagnetic shielding box to shield the electromagnetic field generated by the inductor from interfering with the control and measurement circuits. The freewheeling circuit 32 is connected to a freewheeling diode D3 and a latching IGBT T6.

[0041] In one embodiment, if Figure 2 As shown, the load capacitance energy compensation circuit 31 includes: a second capacitor C2, a third resistor R3, a fourth resistor R4, a third controllable device T9, a fourth controllable device T10 and a second protection device T5, wherein the positive electrode of the second capacitor C2 is respectively connected to one end of the third resistor R3, one end of the fourth resistor R4 and the first end of the second protection device T5, and the negative electrode of the second capacitor C2 is connected to the negative electrode of the external DC power supply and then grounded; the second end of the second protection device T5 is connected to the other end of the bridge arm current inductor L1; the other end of the fourth resistor R4 is connected to the negative electrode of the second capacitor C2 through the fourth controllable device T10; the other end of the third resistor R3 is connected to the positive electrode of the external DC power supply through the third controllable device T9.

[0042] In one specific embodiment, the third resistor R3 and the fourth resistor R4 are power resistors used to limit the charging and discharging speeds of the capacitor. The third controllable device T9 is a charging IGBT, and the fourth controllable device T10 is a charging IGBT. The control terminals of the third and fourth controllable devices T9 and T10 are connected to an external remote control device. The external remote control device controls the charging and discharging of the second capacitor C2 by controlling the on and off of the charging and discharging IGBTs.

[0043] Specifically, when charging the second capacitor C1, the external DC power supply is first adjusted to the required voltage value. The external remote control device then sends a pulse signal to control the third controllable device T9 to turn on. The external DC power supply charges the second capacitor C2 to the required voltage for the experiment through the diode D5, the power resistor R3, and the third controllable device T9. When discharging the second capacitor C2, the external remote control device sends a pulse signal to control the fourth controllable device T10 to turn on. The second capacitor C2 is discharged through the power resistor R4 and the fourth controllable device T10. During the experiment, the charging and discharging of each capacitor is remotely controlled to ensure personnel safety.

[0044] In an embodiment of the present invention, the second protection device T5 is an IGBT. A bridge arm current loop protection IGBT (T5) is connected between the positive electrode of the load capacitor (C2) and the bridge arm current inductor (L1). When the upper tube tested IGBT or the lower tube tested IGBT is damaged and cannot be shut down normally, the bridge arm current loop protection IGBT can shut down the load current.

[0045] In one embodiment, the drive circuit 4 includes a drive tab, a gate resistor, and an IGBT driver board. The IGBT driver board is connected to the G terminal of the upper IGBT device under test (T1) and the G terminal of the lower IGBT device under test (T2) via the drive tab. The drive gate resistor is connected to the circuit board using a test socket. The drive tab is specially designed to have low mutual inductance with the short-circuit loop, minimizing the impact of the short-circuit current on the drive voltage. The drive tab is enclosed in a metal shielding box.

[0046] In one embodiment, when performing a Class I short-circuit test, the IGBT under test is the second device under test (DUT) T2. The first device under test (DUT) T1 is replaced with a wire, short-circuiting the first device under test (DUT) T1. The bridge arm current inductor (L1) is disconnected, thereby disconnecting the bridge arm inductor (L1). The first controllable device (T7) is turned on, and the first capacitor (C1) is charged to the voltage required for the Class I short-circuit test. The second device under test (DUT) T2 is then triggered to conduct, and a Class I short circuit occurs at this voltage.

[0047] In one embodiment, when performing a second type short circuit test, the IGBT under test is the first device under test T1. The second device under test T2 and the second diode D2 connected in reverse parallel to the second device under test T2 are removed, thereby disconnecting the second device under test T2. The first controllable device T7 is turned on, and the first capacitor C1 is charged to the voltage U required by the second type short circuit test. SM Then the remote control triggers the third controllable device T9 to turn on, charging the second capacitor C2 to a certain voltage value U C2 . Control the on-time T of the upper tube IGBT (T1) under test on , the bridge arm inductor L1 generates the bridge arm current to the target value I arm =((U SM -U C2 )*T on ) / L1, establish the bridge arm current flowing out of the submodule as the load current, the IGBT (T1) under test remains turned on and the load current flowing through triggers the auxiliary device T3 to turn on, causing the second type of short circuit to occur in the first device under test T1.

[0048] In one embodiment, when performing a third-type short-circuit test, the IGBT under test is the first device under test T1 and its antiparallel diode D1. The second device under test T2 and the second diode D2 antiparallel to the second device under test T2 are removed, thereby disconnecting the second device under test T2. After setting the voltage of the adjustable DC power supply source1, the first controllable device T7 is remotely triggered to turn on, and the first capacitor C1 is charged to establish the submodule bus voltage U SM The remote control triggers the third controllable device T9 to turn on, charging the second capacitor C2 to a certain voltage value U C2 After that, the auxiliary device T3 is controlled to conduct for a certain time. on , the bridge arm inductor L1 generates the bridge arm current to the target value I arm =(U C2 *T on ) / L1, establishing a bridge arm current flowing into the submodule as the load current, and the IGBT (T1) under test remains on. However, the load current flows through the first diode D1 instead of the first device under test T1, triggering the auxiliary device T3 to turn on, causing the first device under test T1 to experience a third-category short circuit.

[0049] In one embodiment, the data acquisition circuit 5 includes: a first high-voltage voltage measuring probe V2, a second high-voltage voltage measuring probe V1, a low-voltage differential active voltage measuring probe V3, a low-voltage passive voltage measuring probe V4, a first drive current measuring device I3, a second drive current measuring device I4, a short-circuit current measuring device I1 and a bridge arm current measuring device I2.

[0050] In a specific embodiment, if Figure 2 As shown, a first high-voltage voltage measuring probe V2 is connected to a first terminal of a second device under test T2; a second high-voltage voltage measuring probe V1 is connected to a first terminal of the first device under test T1; a low-voltage differential active voltage measuring probe V3 is connected to a control terminal of the first device under test T1; a low-voltage passive voltage measuring probe V4 is connected to a control terminal of the second device under test T2; a first drive current measuring device I3 is mounted on a drive wiring piece connected to the first device under test T1 in a drive circuit 4; a second drive current measuring device I4 is mounted on a drive wiring piece connected to the second device under test T2 in a drive circuit 4; a short-circuit current measuring device I1 is mounted on a second terminal of the second device under test T2; and a bridge arm current measuring device I2 is mounted on a circuit mounted on a bridge arm current generating circuit 3.

[0051] In the embodiment of the present invention, the V of the upper tube IGBT under test measured by the first high voltage voltage measuring probe V2 is CE And the short-circuit current waveform I measured by the short-circuit current measuring device I1 C It can be determined whether the upper tube IGBT under test has failed and the reason for the failure. Similarly, the V CEAnd the short-circuit current waveform I measured by the short-circuit current measuring device I1 C It can determine whether the IGBT under test on the lower tube has failed and the cause of the failure.

[0052] Furthermore, by repeating the experiment under different stress parameters, the short-circuit withstand limits of the device (maximum voltage, maximum current, withstand duration, safe operating area, etc.) can be summarized. By measuring the gate drive of the upper and lower IGBTs under test (V3, V4, I3, I4), the effect of the gate signal on short-circuit regulation can be analyzed, allowing for the development of more reasonable drive control strategies and strengthening the driver's short-circuit protection capabilities.

[0053] In an embodiment of the present invention, the first driving current measuring device I3 and the second driving current measuring device I4 are wrapped in a metal shielding box, and the shielding box is used to shield the first driving current measuring device I3 and the second driving current measuring device I4 from interference from an external magnetic field.

[0054] In summary, compared with the prior art, the present invention has the following advantages:

[0055] 1. The present invention provides an IGBT device short-circuit test device, which can be equivalent to a sub-module direct short-circuit condition with the influence of bridge arm current.

[0056] 2. The present invention provides an IGBT device short-circuit test device that can perform three types of IGBT standard short-circuit tests.

[0057] 3. The present invention provides an IGBT device short-circuit test device, in which the bus voltage of the platform submodule and the bridge arm current size and direction can be adjusted according to the experimental requirements.

[0058] 4. The present invention provides an IGBT device short-circuit test device with a continuous short-circuit protection mechanism. When the IGBT under test fails and a continuous short circuit occurs during the experiment, the protective IGBT can shut off the short-circuit current.

[0059] The embodiment of the present invention also provides an IGBT device short circuit test method based on the following Figure 2 The IGBT device short circuit test device shown in Figure 3 As shown, the IGBT device short-circuit test method includes the following steps:

[0060] Step S1: Establishing the bus voltage of the submodule of the device under test.

[0061] In a specific embodiment, the bus voltage of the submodule can be set by an external adjustable DC power supply. After the voltage of the adjustable DC power supply source1 is set, the first controllable device T7 is remotely triggered to turn on, and the first capacitor C1 is charged to establish the bus voltage U SM .

[0062] Step S2: establishing the arm current of the submodule of the device under test according to the preset experiment requirements. The preset experiments include a first type of short circuit test, a second type of short circuit test, and a third type of short circuit test.

[0063] In a specific embodiment, the bridge arm current flowing into the submodule and the bridge arm current flowing out of the submodule are respectively established according to different experiment types.

[0064] In the embodiment of the present invention, to establish the bridge arm current flowing into the submodule, it is necessary to set the voltage of the adjustable DC power source 1, remotely trigger the third controllable device T9 to turn on, and charge the second capacitor C2 to a certain voltage value U C2 Then control the conduction time T of the IGBT (T2) under test. on , the bridge arm inductor L1 generates the bridge arm current to the target value I arm =(U C2 *T on ) / L1.

[0065] When establishing the bridge arm current flowing out of the submodule, it is also necessary to set the voltage of the adjustable DC power source 1, remotely trigger the first controllable device T7 to turn on, and charge the first capacitor C1 to establish the submodule bus voltage U SM Then the remote control triggers the third controllable device T9 to turn on, charging the second capacitor C2 to a certain voltage value U C2 . Control the on-time T of the upper tube IGBT (T1) under test on , the bridge arm inductor L1 generates the bridge arm current to the target value I arm =((U SM -U C2 )*T on ) / L1.

[0066] In the embodiment of the present invention, the magnitude of the bridge arm current can be adjusted according to the above formula to adjust the voltage U of the second capacitor C2. C2 Or adjust the on-time Ton of the upper tube IGBT (T1) under test.

[0067] Step S3: Control the driving circuit to generate a pulse signal according to the preset experimental requirements, and control the corresponding device under test to connect to the short-circuit test main circuit to perform a short-circuit test according to the pulse signal.

[0068] In a specific embodiment, when performing the first type of short-circuit test, the pulse signal is used to control the corresponding device under test to connect to the short-circuit test main circuit to perform the short-circuit test, including the following steps:

[0069] Step S310: bypass the first device under test T1 and disconnect the bridge arm current inductor L1.

[0070] Step S311: Turn on the first controllable device T7 to charge the first capacitor C1 to a first preset voltage.

[0071] Step S312: triggering the second device under test T2 to turn on, and causing a first type short circuit to occur in the second device under test T2.

[0072] In an embodiment of the present invention, during the first type of short-circuit test, the IGBT under test is the second device under test T2, and the first device under test T1 is replaced with a wire to short-circuit the first device under test T1. The bridge arm current inductor L1 is unplugged, thereby disconnecting the bridge arm inductor L1. The first controllable device T7 is turned on, and the first capacitor C1 is charged to the voltage required for the first type of short-circuit test. The second device under test T2 is triggered to turn on, and the second device under test T2 undergoes a first type of short circuit at this voltage. In an embodiment of the present invention, the first preset voltage is set according to the requirements of the first type of short-circuit test.

[0073] Furthermore, when the second type of short-circuit test is performed, the corresponding device under test is controlled to be connected to the short-circuit test main circuit according to the pulse signal to perform the short-circuit test, which includes the following steps:

[0074] Step S320: disconnect the second device under test T2.

[0075] Step S321: Turn on the first controllable device T7 to charge the first capacitor C1 to a second preset voltage.

[0076] Step S322: Turn on the third controllable device T9 to charge the second capacitor C2 to a third preset voltage.

[0077] Step S323: Utilize the first capacitor C1 and the second capacitor C2 to establish a bridge arm current flowing out of the submodule.

[0078] Step S324 : Turning on the first device under test T1 and the auxiliary device T3 , a second type of short circuit occurs in the first device under test T1 .

[0079] Specifically, when performing the second type short circuit test, the IGBT under test is the first device under test T1. The second device under test T2 and the second diode D2 connected in reverse parallel to the second device under test T2 are unplugged, thereby disconnecting the second device under test T2. The first controllable device T7 is turned on, and the first capacitor C1 is charged to the voltage required by the second type short circuit test U SM Then the remote control triggers the third controllable device T9 to turn on, charging the second capacitor C2 to a certain voltage value U C2 . Control the on-time T of the upper tube IGBT (T1) under test on , the bridge arm inductor L1 generates the bridge arm current to the target value I arm =((U SM -U C2 )*T on) / L1, establishing a bridge arm current flowing out of the submodule as the load current. The IGBT (T1) under test remains on, and the load current flowing through it triggers the auxiliary device T3 to turn on, causing a second-type short circuit in the first device under test T1. In this embodiment of the present invention, the second preset voltage and the third preset voltage are set according to the requirements of the second-type short circuit test.

[0080] Furthermore, when performing the third type of short-circuit test, the corresponding device under test is controlled to connect to the short-circuit test main circuit according to the pulse signal to perform the short-circuit test, which includes the following steps:

[0081] Step S330: disconnect the second device under test T2.

[0082] Step S331 : Turn on the first controllable device T7 to charge the first capacitor C1 to a fourth preset voltage.

[0083] Step S332: Turn on the third controllable device T9 to charge the second capacitor C2 to a fifth preset voltage.

[0084] Step S333: using the second capacitor C2 to establish a bridge arm current flowing into the submodule.

[0085] Step S334 : Turning on the first device under test T1 and the auxiliary device T3 , a third type short circuit occurs in the first device under test T1 .

[0086] Specifically, when performing the third type of short-circuit test, the IGBT under test is the first device under test T1 and its anti-parallel diode D1. The second device under test T2 and the second diode D2 anti-parallel to the second device under test T2 are unplugged, thereby disconnecting the second device under test T2. After setting the voltage of the adjustable DC power supply source1, the first controllable device T7 is remotely triggered to turn on, and the first capacitor C1 is charged to establish the submodule bus voltage U SM The remote control triggers the third controllable device T9 to turn on, charging the second capacitor C2 to a certain voltage value U C2 After that, the auxiliary device T3 is controlled to conduct for a certain time. on , the bridge arm inductor L1 generates the bridge arm current to the target value I arm =(U C2 *T on ) / L1, establishing a bridge arm current flowing into the submodule as the load current, and the IGBT (T1) under test remains on. However, the load current flows through the first diode D1 rather than the first device under test T1, triggering the auxiliary device T3 to turn on, causing the first device under test T1 to experience a third-category short circuit. In this embodiment of the present invention, the fourth and fifth preset voltages are set based on the requirements of the third-category short-circuit test.

[0087] Step S4: Acquire experimental data collected by the data acquisition circuit, and evaluate the reliability of the device under test based on the experimental data.

[0088] In a specific embodiment, the V of the upper tube IGBT under test measured by the first high voltage voltage measuring probe V2 is CE And the short-circuit current waveform I measured by the short-circuit current measuring device I1 C It can be determined whether the upper tube IGBT under test has failed and the reason for the failure. Similarly, the V CE And the short-circuit current waveform I measured by the short-circuit current measuring device I1 C It can determine whether the IGBT under test on the lower tube has failed and the cause of the failure.

[0089] Furthermore, by repeating the experiment under different stress parameters, the short-circuit withstand limits of the device (maximum voltage, maximum current, withstand duration, safe operating area, etc.) can be summarized. By measuring the gate drive of the upper and lower IGBTs under test (V3, V4, I3, I4), the effect of the gate signal on short-circuit regulation can be analyzed, allowing for the development of more reasonable drive control strategies and strengthening the driver's short-circuit protection capabilities.

[0090] The IGBT device short-circuit test method provided by the present invention includes: establishing a bus voltage of a submodule of the device to be tested; establishing a bridge arm current of the submodule of the device to be tested according to preset experimental requirements, wherein the preset experiments include a first type of short-circuit test, a second type of short-circuit test, and a third type of short-circuit test; controlling a drive circuit to generate a pulse signal according to the preset experimental requirements, and controlling the corresponding device to be tested to connect to a short-circuit test main circuit to perform a short-circuit test according to the pulse signal; obtaining experimental data collected by a data acquisition circuit, and evaluating the reliability of the device to be tested based on the experimental data. By equivalently treating a submodule direct short-circuit condition with the influence of the bridge arm current, a short-circuit test environment is provided for the IGBT device. Three types of IGBT standard short-circuit tests can be performed on the IGBT device of a converter valve with a submodule IGBT direct short-circuit, which plays an important guiding role in the domestic development and engineering application of converter valves.

[0091] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. An IGBT device short circuit test device, characterized in that: include: Busbar capacitor energy replenishment circuit, short circuit test main circuit, bridge arm current generation circuit, drive circuit and data acquisition circuit, among which, The two ends of the bus capacitor energy compensation circuit are connected to the positive and negative poles of the external DC power supply respectively, and the bus capacitor energy compensation circuit is also connected in parallel with the short circuit test main loop; The two ends of the bridge arm current generating circuit are connected to the positive and negative poles of the external DC power supply respectively, and the bridge arm current generating circuit is also connected to the short circuit test main loop; The driving circuit is connected to the short-circuit test main circuit; The data acquisition circuit is connected to the short-circuit test main loop and the bridge arm current generating circuit respectively; IGBT device short circuit test methods include: Establish the bus voltage of the submodule of the device under test; Establish the bridge arm current of the submodule of the device under test according to the preset experimental requirements. The preset experiments include the first type of short-circuit test, the second type of short-circuit test and the third type of short-circuit test; Control the drive circuit to generate a pulse signal according to the preset experimental requirements, and control the corresponding device under test to connect to the short-circuit test main circuit to perform a short-circuit test according to the pulse signal; Obtain experimental data collected by the data acquisition circuit and evaluate the reliability of the device under test based on the experimental data; When the first type of short-circuit test is performed, controlling the corresponding device under test to connect to the short-circuit test main circuit to perform the short-circuit test according to the pulse signal includes: Bypass the first device under test and disconnect the bridge arm current inductor; Turning on the first controllable device to charge the first capacitor to a first preset voltage; triggering the second device under test to turn on, causing a first type short circuit to occur in the second device under test; When the second type of short-circuit test is performed, controlling the corresponding device under test to connect to the short-circuit test main circuit to perform the short-circuit test according to the pulse signal includes: Disconnecting the second device under test; Turning on the first controllable device to charge the first capacitor to a second preset voltage; Turning on the third controllable device to charge the second capacitor to a third preset voltage; Using the first capacitor and the second capacitor to establish a bridge arm current flowing out of the submodule; The first device under test and the auxiliary device are turned on, and a second type short circuit occurs in the first device under test.

2. The IGBT device short-circuit test device according to claim 1, characterized in that: The short circuit test main circuit includes: a first device under test, a second device under test, a first diode, a second diode, an auxiliary device and a first protection device, wherein: The first device under test is connected in reverse parallel to the first diode, and the second device under test is connected in reverse parallel to the second diode; The first end of the first device under test is connected to one end of the bus capacitor energy compensation circuit through the first protection device, the second end of the first device under test is connected to the first end of the second device under test, the first end of the auxiliary device and the bridge arm current generating circuit respectively, and the control end of the first device under test is connected to the driving circuit; The control terminal of the second device under test is connected to the driving circuit, and the second terminal of the second device under test and the second terminal of the auxiliary device are both grounded.

3. The IGBT device short circuit test device according to claim 2, characterized in that: The bus capacitor energy compensation circuit includes: a first capacitor, a first resistor, a second resistor, a first controllable device and a second controllable device, wherein: The positive electrode of the first capacitor is connected to one end of the second resistor, the first end of the first controllable device, and the first end of the first protection device respectively, and the negative electrode of the first capacitor is connected to the negative electrode of the external DC power supply and then grounded; The other end of the second resistor is connected to the negative electrode of the first capacitor through the second controllable device; The second end of the first controllable device is connected to the positive electrode of the external DC power supply through the first resistor.

4. The IGBT device short circuit test device according to claim 2, characterized in that: The bridge arm current generating circuit includes: a bridge arm current inductor, a load capacitor energy compensation circuit and a freewheeling loop, wherein: One end of the bridge arm current inductor is connected to the second end of the first device under test, the first end of the second device under test, and the first end of the auxiliary device respectively, and the other end of the bridge arm current inductor is connected to the load capacitor energy compensation circuit; The two ends of the load capacitor energy compensation circuit are connected to the positive and negative poles of the external DC power supply respectively; The freewheeling loop is connected in parallel with the bridge arm current inductor.

5. The IGBT device short-circuit test device according to claim 4, characterized in that: The load capacitance energy replenishing circuit includes: a second capacitor, a third resistor, a fourth resistor, a third controllable device, a fourth controllable device and a second protection device, wherein: The positive electrode of the second capacitor is connected to one end of the third resistor, one end of the fourth resistor and the first end of the second protection device respectively, and the negative electrode of the second capacitor is connected to the negative electrode of the external DC power supply and then grounded; The second end of the second protection device is connected to the other end of the bridge arm current inductor; The other end of the fourth resistor is connected to the negative electrode of the second capacitor through the fourth controllable device; The other end of the third resistor is connected to the positive electrode of the external DC power supply through the third controllable component.

6. The IGBT device short circuit test device according to claim 2, characterized in that: The data acquisition circuit includes: a first high-voltage voltage measuring probe, a second high-voltage voltage measuring probe, a low-voltage differential active voltage measuring probe, a low-voltage passive voltage measuring probe, a first drive current measuring device, a second drive current measuring device, a short-circuit current measuring device and a bridge arm current measuring device, wherein, The first high-voltage voltage measuring probe is connected to the first end of the second device under test; the second high-voltage voltage measuring probe is connected to the first end of the first device under test; the low-voltage differential active voltage measuring probe is connected to the control end of the first device under test; the low-voltage passive voltage measuring probe is connected to the control end of the second device under test; the first drive current measuring device is installed on the drive wiring piece connected to the first device under test in the drive circuit; the second drive current measuring device is installed on the drive wiring piece connected to the second device under test in the drive circuit; the short-circuit current measuring device is installed on the second end of the second device under test; and the bridge arm current measuring device is installed on the circuit installed in the bridge arm current generating circuit.

7. A short-circuit test method for an IGBT device, characterized in that: Based on the IGBT device short-circuit test device according to any one of claims 1 to 6, the IGBT device short-circuit test method includes: Establish the bus voltage of the submodule of the device under test; Establish the bridge arm current of the submodule of the device under test according to the preset experimental requirements. The preset experiments include the first type of short-circuit test, the second type of short-circuit test and the third type of short-circuit test; Control the drive circuit to generate a pulse signal according to the preset experimental requirements, and control the corresponding device under test to connect to the short-circuit test main circuit to perform a short-circuit test according to the pulse signal; Obtain experimental data collected by the data acquisition circuit and evaluate the reliability of the device under test based on the experimental data; When the first type of short-circuit test is performed, controlling the corresponding device under test to connect to the short-circuit test main circuit to perform the short-circuit test according to the pulse signal includes: Bypass the first device under test and disconnect the bridge arm current inductor; Turning on the first controllable device to charge the first capacitor to a first preset voltage; triggering the second device under test to turn on, causing a first type short circuit to occur in the second device under test; When the second type of short-circuit test is performed, controlling the corresponding device under test to connect to the short-circuit test main circuit to perform the short-circuit test according to the pulse signal includes: Disconnecting the second device under test; Turning on the first controllable device to charge the first capacitor to a second preset voltage; Turning on the third controllable device to charge the second capacitor to a third preset voltage; Using the first capacitor and the second capacitor to establish a bridge arm current flowing out of the submodule; The first device under test and the auxiliary device are turned on, and a second type short circuit occurs in the first device under test.

8. The IGBT device short-circuit test method according to claim 7, characterized in that: When the third type short-circuit test is performed, controlling the corresponding device under test to connect to the short-circuit test main circuit to perform the short-circuit test according to the pulse signal includes: Disconnecting the second device under test; Turning on the first controllable device to charge the first capacitor to a fourth preset voltage; turning on the third controllable device to charge the second capacitor to a fifth preset voltage; Using the second capacitor to establish a bridge arm current flowing into the submodule; The first device under test and the auxiliary device are turned on, and a third type short circuit occurs in the first device under test.

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