A surge voltage test circuit and method for a rectifier bridge module

Abstract

The present invention provides a surge voltage test circuit and method for a rectifier bridge module, and relates to the technical field of rectifier bridge testing, including: a bridge arm selection switch group is connected between an upper bridge arm and a lower bridge arm of each bridge arm; an upper and lower bridge selection switch group connects the cathode terminal and the anode terminal of the rectifier bridge module, and a surge generating end of a surge generating circuit connects the upper and lower bridge selection switch groups; according to the received test instruction, the bridge arm selection switch group and the switches in the upper and lower bridge selection switch groups are controlled to open and close to select an upper bridge arm or a lower bridge arm in one of the bridge arms of the rectifier bridge module to be connected to the surge generating circuit to form a test loop, and then the surge generating circuit is controlled to generate a surge voltage and the voltage waveform is detected and sent to a host computer for test passing judgment. The beneficial effect is that the cumbersome steps of manually connecting or disconnecting multiple test lines are avoided, and the convenience of the test is significantly improved. The automated testing method not only improves the test efficiency, but also reduces the errors caused by manual operation.

Description

Technical Field

[0001] The present invention relates to the technical field of rectifier bridge testing, and in particular to a surge voltage testing circuit and method for a rectifier bridge module. Background Art

[0002] In the power system, power surge is an important issue that cannot be ignored. It is usually caused by external factors such as lightning strikes, power failures, switching operations, etc., resulting in instantaneous voltage changes in a short period of time. This sudden voltage change may cause serious damage to the equipment in the system, especially those components that are sensitive to voltage fluctuations. As a key component in the power system, the rectifier bridge module is responsible for converting AC power into DC power. The stability and reliability of its performance are crucial to the safe operation of the entire system.

[0003] Testing the surge voltage withstand capacity of the rectifier bridge module is an important measure to ensure the safe operation of power equipment and systems. However, in the existing technology, the surge voltage test of the rectifier bridge module often has some shortcomings. The existing test methods may not be convenient enough. Traditional test circuits may be more complicated and require more test equipment and steps, which not only increases the cost of the test, but also may reduce the efficiency of the test. In practical applications, convenient test methods can find problems more quickly, so that timely measures can be taken to prevent potential equipment damage and system failures.

[0004] In summary, the existing technology has deficiencies in convenience and accuracy in the surge voltage test of the rectifier bridge module. These problems may not only affect the reliability of the test results, but also pose a potential threat to the safe operation of power equipment and systems. Therefore, a more convenient and accurate testing method is needed to better evaluate the surge voltage withstand capacity of the rectifier bridge module and ensure the stable operation of power equipment and systems. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a surge voltage test circuit of a rectifier bridge module, wherein the rectifier bridge module comprises a plurality of bridge arms connected in parallel, each bridge arm comprises an upper bridge arm and a lower bridge arm connected in series, and the surge voltage test circuit comprises:

[0006] A bridge arm selection switch group, wherein the bridge arm side connection terminal of the bridge arm selection switch group is connected between the upper bridge arm and the lower bridge arm of each bridge arm;

[0007] An upper and lower bridge selection switch group, wherein the bridge arm side terminal of the upper and lower bridge selection switch group is connected to the cathode terminal and the anode terminal of the rectifier bridge module, and the bridge arm selection terminal of the upper and lower bridge selection switch group is connected to the surge side terminal of the bridge arm selection switch group;

[0008] A surge generating circuit, wherein a surge generating end of the surge generating circuit is connected to a surge side terminal of the upper and lower bridge selection switch group;

[0009] The control box is electrically connected to the bridge arm selection switch group, the upper and lower bridge selection switch groups and the surge generating circuit respectively, and is used to control the opening and closing of the switches in the bridge arm selection switch group and the upper and lower bridge selection switch groups according to the received test instructions to select the upper bridge arm or the lower bridge arm of one of the bridge arms of the rectifier bridge module to be connected to the surge generating circuit to form a test loop, and then control the surge generating circuit to generate a surge voltage and detect the voltage waveform to send to the host computer for test pass judgment.

[0010] Preferably, the surge generating circuit comprises:

[0011] An insulated gate bipolar transistor, wherein the collector of the insulated gate bipolar transistor is connected to one end of an inductor, the other end of the inductor is connected to the positive electrode of a DC power supply, the emitter of the insulated gate bipolar transistor is connected to the negative electrode of the DC power supply, and the gate of the insulated gate bipolar transistor is connected to the control box;

[0012] The energy storage capacitor is connected in parallel between the positive and negative electrodes of the DC power supply.

[0013] Preferably, the upper and lower bridge selection switch group includes a normally open upper bridge arm switch group and a lower bridge arm switch group;

[0014] The upper bridge arm switch group includes:

[0015] a first switch, wherein one end of the first switch is connected to the cathode terminal of the rectifier bridge module, and the other end of the first switch is connected to the collector of the insulated gate bipolar transistor;

[0016] a second switch, one end of the second switch being connected to the surge side terminal of the bridge arm selection switch group, and the other end of the second switch being connected to the emitter of the insulated gate bipolar transistor;

[0017] The lower bridge wall switch group includes:

[0018] a third switch, one end of the third switch being connected to the anode terminal of the rectifier bridge module, and the other end of the third switch being connected to the emitter of the insulated gate bipolar transistor;

[0019] A fourth switch, one end of the fourth switch is connected to the surge side terminal of the bridge arm selection switch group, and the other end of the fourth switch is connected to the collector of the insulated gate bipolar transistor.

[0020] Preferably, the bridge arm selection switch group includes a plurality of bridge arm selection switches, and each of the bridge arm selection switches corresponds to each of the bridge arms one by one;

[0021] For each of the bridge arm selection switches, one end of the bridge arm selection switch is connected between the upper bridge arm and the lower bridge arm of the corresponding bridge arm, and the other end of the bridge arm selection switch is connected to the bridge arm selection connection terminal of the upper and lower bridge selection switch groups;

[0022] Each of the bridge arm selection switches is normally open.

[0023] Preferably, each bridge arm has a bridge arm number, and the control box includes:

[0024] The bridge arm selection module is used to close the corresponding bridge arm selection switch according to the bridge arm number contained in the test instruction.

[0025] Preferably, the control box also includes:

[0026] The upper and lower bridge selection module is used to turn on the upper bridge arm switch group when the upper and lower bridge arm types contained in the test instruction are upper bridge arms, and to turn on the lower bridge arm switch group when the upper and lower bridge arm types contained in the test instruction are lower bridge arms.

[0027] Preferably, the control box further comprises a voltage probe, which is respectively connected to the collector and the emitter of the insulated gate bipolar transistor: and

[0028] The test start module is used to send a single pulse signal to the gate of the insulated gate bipolar transistor after controlling the switches in the bridge arm selection switch group and the upper and lower bridge selection switch groups to close, and then detect the voltage waveform obtained by the voltage probe and send it to the host computer for test pass judgment.

[0029] The present invention also provides a surge voltage testing method for a rectifier bridge module, which is applied to the above-mentioned surge voltage testing circuit, comprising:

[0030] Step S1, the control box controls the switches in the bridge arm selection switch group to close according to an external test instruction to select the corresponding bridge arm as the bridge arm to be tested;

[0031] Step S2, the control box controls the switches in the upper and lower bridge selection switch group to close according to the external test instruction so as to connect the upper bridge arm or the lower bridge arm of the bridge arm to be tested with the surge generation circuit to form a test loop;

[0032] Step S3, the control box sends a pulse to the surge generating circuit to generate a surge voltage, and detects the voltage waveform and sends it to the host computer for test passing judgment.

[0033] The above technical solution has the following advantages or beneficial effects:

[0034] 1. It avoids the tedious steps of manually connecting or disconnecting multiple test lines in traditional test methods, significantly improving the convenience of testing. The automated testing method not only improves test efficiency, but also reduces errors caused by manual operation.

[0035] 2. Accurately controlling the bridge arms to be connected to the surge generating circuit and testing them separately in sequence helps to improve the accuracy of the test. By accurately controlling the generation and detection of surge voltage, the present invention can more accurately evaluate the surge voltage tolerance of the rectifier bridge module. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The figure is a schematic structural diagram of a surge voltage test circuit of a rectifier bridge module in a preferred embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of the structure of the control box 24 in a preferred embodiment of the present invention;

[0038] Figure 3 The figure is a flow chart of a surge voltage testing method for a rectifier bridge module in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0039] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The present invention is not limited to this embodiment, and other embodiments may also fall within the scope of the present invention as long as they conform to the gist of the present invention.

[0040] In a preferred embodiment of the present invention, based on the above problems existing in the prior art, a surge voltage test circuit of a rectifier bridge module is provided. The rectifier bridge module 1 includes a plurality of parallel bridge arms 11, each of which includes an upper bridge arm 111 and a lower bridge arm 112 connected in series. Figure 1 and Figure 2 As shown, the surge voltage test circuit 2 includes:

[0041] A bridge arm selection switch group 21, wherein the bridge arm side connection terminal of the bridge arm selection switch group 21 is connected between the upper bridge arm 111 and the lower bridge arm 112 of each bridge arm 11;

[0042] The upper and lower bridge selection switch group 22, the bridge arm side terminal of the upper and lower bridge selection switch group 22 is connected to the cathode terminal and the anode terminal of the rectifier bridge module 1, and the bridge arm selection terminal of the upper and lower bridge selection switch group 22 is connected to the surge side terminal of the bridge arm selection switch group 21;

[0043] A surge generating circuit 23, wherein a surge generating end of the surge generating circuit 23 is connected to a surge side terminal of the upper and lower bridge selection switch group 22;

[0044] The control box 24 is electrically connected to the bridge arm selection switch group 21, the upper and lower bridge selection switch group 22 and the surge generating circuit 23, respectively, and is used to control the opening and closing of the bridge arm selection switch group 21 and the upper and lower bridge selection switch group 22 according to the received test instructions to select the upper bridge arm 111 or the lower bridge arm 112 in one of the bridge arms 11 of the rectifier bridge module 1 to be connected to the surge generating circuit 23 to form a test loop, and then control the surge generating circuit 23 to generate a surge voltage and detect the voltage waveform to send to the host computer for test pass judgment.

[0045] Specifically, the present invention introduces a bridge arm selection switch group 21 and an upper and lower bridge selection switch group 22. The design of these two switch groups allows the tester to conveniently select any bridge arm 11 in the rectifier bridge module 1, and the upper bridge arm 111 or the lower bridge arm 112 in the bridge arm 11 for testing. This design avoids the tedious steps of manually connecting or disconnecting multiple test lines in the traditional test method, and significantly improves the convenience of the test.

[0046] By precisely controlling the opening and closing of the bridge arm selection switch group 21 and the upper and lower bridge selection switch group 22, the present invention can ensure that during the test, only the selected bridge arm 11 part forms a conduction loop with the surge generation circuit, thereby avoiding the influence of other unselected bridge arms on the test results. This precise control helps to improve the accuracy of the test.

[0047] In addition, the surge generation circuit in the present invention can generate a surge voltage with a specific waveform and amplitude to simulate the surge conditions that may be encountered in an actual power system. By precisely controlling the generation and detection of the surge voltage, the present invention can more accurately evaluate the surge voltage tolerance of the rectifier bridge module.

[0048] The control box 24 in the present invention serves as a core control unit, which can receive test instructions and automatically control the operation of the bridge arm selection switch group 21, the upper and lower bridge selection switch group 22 and the surge generation circuit 23. This automated testing method not only improves the test efficiency, but also reduces the errors caused by human operation.

[0049] By sending the test results (such as voltage waveform) to a host computer for further analysis and judgment, the present invention can also realize automatic processing and storage of test data, which provides convenience for subsequent test analysis and equipment maintenance.

[0050] In summary, the present invention effectively solves the technical defects of the prior art such as insufficient testing convenience, low testing accuracy and lack of automated testing means by introducing innovative designs such as the bridge arm selection switch group 21, the upper and lower bridge selection switch group 22, the surge generation circuit 23 and the control box 24. These innovative designs not only improve the efficiency and accuracy of the surge voltage test of the rectifier bridge module, but also provide a strong guarantee for the safe operation of the power system.

[0051] In a preferred embodiment of the present invention, the surge generating circuit 23 comprises:

[0052] An insulated gate bipolar transistor IGBT, the collector of the insulated gate bipolar transistor IGBT is connected to one end of the inductor L1, the other end of the inductor L1 is connected to the positive electrode of the DC power supply DC, the emitter of the insulated gate bipolar transistor IGBT is connected to the negative electrode of the DC power supply DC, and the gate of the insulated gate bipolar transistor IGBT is connected to the control box 24; an IGBT device with a withstand voltage of 4500V is preferred.

[0053] The energy storage capacitor C1 is connected in parallel between the positive and negative electrodes of the DC power supply DC.

[0054] In a preferred embodiment of the present invention, the control box 24 further includes a voltage probe, which is respectively connected to the collector and the emitter of the insulated gate bipolar transistor; and

[0055] The test start module 243 is used to send a single pulse signal to the gate of the insulated gate bipolar transistor after the switches in the control bridge arm selection switch group and the upper and lower bridge selection switch groups are closed, and then the voltage waveform obtained by voltage probe detection is sent to the host computer for test pass judgment.

[0056] Specifically, the surge test is intended to simulate the voltage transient mutation phenomenon that may be encountered in the power system (such as surge voltage caused by lightning strikes, power failures, etc.) to evaluate the rectifier bridge module's ability to withstand such voltage fluctuations. The present invention designs a specific surge generation circuit that can generate the required surge voltage under controlled conditions and apply it to the rectifier bridge module to be tested, thereby realizing the test of the rectifier bridge module's surge voltage tolerance.

[0057] like Figure 1 As shown, the surge generating circuit 23 comprises:

[0058] Insulated Gate Bipolar Transistor (IGBT): As the core component of the surge generation circuit, the collector of the IGBT is connected to one end of the inductor L1, and the other end of the inductor L1 is connected to the positive electrode of the DC power supply. The emitter of the IGBT is directly connected to the negative electrode of the DC power supply. The gate of the IGBT is connected to the control box to receive the control signal.

[0059] Energy storage capacitor C1: connected in parallel between the positive and negative poles of the DC power supply. The main function of setting the energy storage capacitor C1 is to store energy, because the IGBT in the surge generation circuit needs to generate a single pulse to generate a corresponding surge voltage. Although the DC power supply DC can also provide voltage, it is not enough to support the energy required for a single pulse. Therefore, an additional energy storage capacitor C1 is required to be set in parallel at both ends of the DC power supply DC for energy storage, to provide a stable DC voltage during the test, and as an energy reserve for surge voltage generation.

[0060] Surge voltage generation:

[0061] When the control box 24 sends a single pulse signal to the IGBT, the IGBT is turned on, and the DC power supply DC supplies power to the IGBT and the subsequent circuits through the inductor L1. At this time, the energy storage capacitor C1 also participates in providing current.

[0062] After the single pulse signal ends, the control box sends a shutdown signal to the IGBT, and the IGBT starts the shutdown process. During the shutdown process, since the current in the inductor L1 cannot change suddenly, a current change rate didt_off will be generated.

[0063] According to Faraday's law of electromagnetic induction, the change of current in the inductor L1 will generate an induced electromotive force ΔV at both ends of the inductor, and the magnitude of the induced electromotive force ΔV is proportional to the product of the current change rate didt_off and the inductance value L1 (ΔV=didt_off*L1).

[0064] This induced electromotive force ΔV will be superimposed on the bus voltage Vcc of the DC power supply, thereby generating a higher voltage Vpk across the collector and emitter of the IGBT.

[0065] Rectifier bridge module surge voltage test:

[0066] The higher voltage Vpk generated during the IGBT shutdown process will be applied to the corresponding upper or lower bridge arm (specifically the diode (DIODE)) in the rectifier bridge module to be tested. Since the diode is equivalent to being connected in anti-parallel at both ends of the IGBT in the circuit, it will also withstand this higher surge voltage.

[0067] By monitoring the voltage Vce (i.e. test data) across the collector and emitter of the IGBT, the performance of the rectifier bridge module under surge voltage can be evaluated.

[0068] The voltage probe transmits the Vce waveform to the oscilloscope, and the oscilloscope then transmits the waveform data back to the host computer software for analysis and judgment to determine whether the rectifier bridge module has passed the surge voltage test.

[0069] The present invention precisely controls the on and off process of the IGBT, utilizes the induced electromotive force generated by the current change in the inductor to superimpose the DC power supply voltage, thereby generating the required surge voltage in the rectifier bridge module. By monitoring and analyzing the voltage waveform of the rectifier bridge module under the surge voltage, its surge voltage tolerance can be evaluated, providing a strong guarantee for the safe operation of the power system. This test method not only has high accuracy and reliability, but also is easy to operate, and is suitable for the surge voltage test requirements of various rectifier bridge modules.

[0070] In a preferred embodiment of the present invention, the upper and lower bridge selection switch group 22 includes a normally open upper bridge arm switch group 221 and a lower bridge arm switch group 222;

[0071] The upper bridge arm switch group 221 includes:

[0072] A first switch K1, one end of the first switch K1 is connected to the cathode terminal of the rectifier bridge module 1, and the other end of the first switch K1 is connected to the collector of the insulated gate bipolar transistor IGBT;

[0073] A second switch K2, one end of the second switch K2 is connected to the surge side terminal of the bridge arm selection switch group 21, and the other end of the second switch K2 is connected to the emitter of the insulated gate bipolar transistor IGBT;

[0074] The lower bridge wall switch group 222 includes:

[0075] A third switch K3, one end of the third switch K3 is connected to the anode terminal of the rectifier bridge module 1, and the other end of the third switch K3 is connected to the emitter of the insulated gate bipolar transistor IGBT;

[0076] The fourth switch K4 has one end connected to the surge side terminal of the bridge arm selection switch group 21 , and the other end connected to the collector of the insulated gate bipolar transistor IGBT.

[0077] In a preferred embodiment of the present invention, the control box 24 also includes:

[0078] The upper and lower bridge selection module 242 is used to turn on the upper bridge arm switch group 221 when the upper and lower bridge arm types contained in the test instruction are upper bridge arms, and to turn on the lower bridge arm switch group 222 when the upper and lower bridge arm types contained in the test instruction are lower bridge arms.

[0079] Specifically, Figure 1 As shown, the rectifier bridge module 1 to be tested includes a plurality of parallel bridge arms 11, each bridge arm includes an upper bridge arm 111 and a lower bridge arm 112. During the test, the bridge arm 11 to be tested is first selected through the bridge arm selection switch group 21, and then the upper bridge arm 111 or the lower bridge arm 112 in the bridge arm 11 is selected through the upper and lower bridge selection switch groups 22 to be connected to the surge sending circuit 23. Therefore, in this embodiment, an upper bridge arm switch group 221 and a lower bridge arm switch group 222 are provided. When the upper bridge arm 111 in the bridge arm 11 needs to be tested, the upper bridge arm switch group 221 is closed, and when the lower bridge arm 112 in the bridge arm 11 needs to be tested, the lower bridge arm switch group 222 is closed. Flexible selection and conduction of the upper and lower bridge arms is realized.

[0080] In a preferred embodiment of the present invention, the bridge arm selection switch group 21 includes a plurality of bridge arm selection switches, and each bridge arm selection switch corresponds to each bridge arm 11 one by one;

[0081] For each bridge arm selection switch, one end of the bridge arm selection switch is connected between the upper bridge arm and the lower bridge arm of the corresponding bridge arm, and the other end of the bridge arm selection switch is connected to the bridge arm selection connection terminal of the upper and lower bridge selection switch groups;

[0082] Each bridge arm selection switch is normally open.

[0083] In a preferred embodiment of the present invention, each bridge arm has a bridge arm number, and the control box 24 includes:

[0084] The bridge arm selection module 241 is used to close the corresponding bridge arm selection switch according to the bridge arm number included in the test instruction.

[0085] Specifically, Figure 1 As shown, there are three bridge arms in the rectifier bridge module to be tested, and the upper computer automatically numbers them in sequence, so the bridge arm selection switch group includes three bridge arm selection switches (S1, S2, and S3 in this embodiment) corresponding to the bridge arm 11. When testing other rectifier bridge modules, for example, including 4, 5, 6, 7, etc. bridge arms, correspondingly increase the bridge arm selection switch and connect it between the upper and lower bridge arms of the corresponding bridge arm. By closing the bridge arm selection switch, the corresponding bridge arm to be tested and the upper and lower bridge selection switch groups are turned on, thereby realizing flexible selection and conduction of the bridge arm.

[0086] The present invention also provides a surge voltage testing method for a rectifier bridge module, which is applied to the above-mentioned surge voltage testing circuit. Figure 3 As shown, including:

[0087] Step S1, the control box controls the switches in the bridge arm selection switch group to close according to the external test instruction to select the corresponding bridge arm as the bridge arm to be tested;

[0088] Step S2, the control box controls the switches in the upper and lower bridge selection switch group to close according to the external test instruction to connect the upper bridge arm or the lower bridge arm of the bridge arm to be tested to the surge generation circuit to form a test loop;

[0089] Step S3, the control box sends a pulse to the surge generation circuit to generate a surge voltage, and detects the voltage waveform and sends it to the host computer for test pass judgment.

[0090] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the contents of this specification and illustrations should be included in the protection scope of the present invention.

Claims

1. A surge voltage test circuit for a rectifier bridge module, characterized in that: The rectifier bridge module includes a plurality of bridge arms connected in parallel, each bridge arm includes an upper bridge arm and a lower bridge arm connected in series, and the surge voltage test circuit includes: A bridge arm selection switch group, wherein the bridge arm side connection terminal of the bridge arm selection switch group is connected between the upper bridge arm and the lower bridge arm of each bridge arm; An upper and lower bridge selection switch group, wherein the bridge arm side terminal of the upper and lower bridge selection switch group is connected to the cathode terminal and the anode terminal of the rectifier bridge module, and the bridge arm selection terminal of the upper and lower bridge selection switch group is connected to the surge side terminal of the bridge arm selection switch group; A surge generating circuit, wherein a surge generating end of the surge generating circuit is connected to a surge side terminal of the upper and lower bridge selection switch group; The control box is electrically connected to the bridge arm selection switch group, the upper and lower bridge selection switch groups and the surge generating circuit respectively, and is used to control the opening and closing of the switches in the bridge arm selection switch group and the upper and lower bridge selection switch groups according to the received test instructions to select the upper bridge arm or the lower bridge arm of one of the bridge arms of the rectifier bridge module to be connected to the surge generating circuit to form a test loop, and then control the surge generating circuit to generate a surge voltage and detect the voltage waveform to send to the host computer for test pass judgment.

2. The surge voltage test circuit according to claim 1, characterized in that: The surge generating circuit comprises: An insulated gate bipolar transistor, wherein the collector of the insulated gate bipolar transistor is connected to one end of an inductor, the other end of the inductor is connected to the positive electrode of a DC power supply, the emitter of the insulated gate bipolar transistor is connected to the negative electrode of the DC power supply, and the gate of the insulated gate bipolar transistor is connected to the control box; The energy storage capacitor is connected in parallel between the positive and negative electrodes of the DC power supply.

3. The surge voltage test circuit according to claim 2, characterized in that: The upper and lower bridge selection switch group includes a normally open upper bridge arm switch group and a lower bridge arm switch group; The upper bridge arm switch group includes: a first switch, wherein one end of the first switch is connected to the cathode terminal of the rectifier bridge module, and the other end of the first switch is connected to the collector of the insulated gate bipolar transistor; a second switch, one end of the second switch being connected to the surge side terminal of the bridge arm selection switch group, and the other end of the second switch being connected to the emitter of the insulated gate bipolar transistor; The lower bridge wall switch group includes: a third switch, one end of the third switch being connected to the anode terminal of the rectifier bridge module, and the other end of the third switch being connected to the emitter of the insulated gate bipolar transistor; A fourth switch, one end of the fourth switch is connected to the surge side terminal of the bridge arm selection switch group, and the other end of the fourth switch is connected to the collector of the insulated gate bipolar transistor.

4. The surge voltage test circuit according to claim 1, characterized in that: The bridge arm selection switch group includes a plurality of bridge arm selection switches, and each of the bridge arm selection switches corresponds to each of the bridge arms one by one; For each of the bridge arm selection switches, one end of the bridge arm selection switch is connected between the upper bridge arm and the lower bridge arm of the corresponding bridge arm, and the other end of the bridge arm selection switch is connected to the bridge arm selection connection terminal of the upper and lower bridge selection switch groups; Each of the bridge arm selection switches is normally open.

5. The surge voltage test circuit according to claim 4, characterized in that: Each of the bridge arms has a bridge arm number, and the control box includes: The bridge arm selection module is used to close the corresponding bridge arm selection switch according to the bridge arm number contained in the test instruction.

6. The surge voltage test circuit according to claim 3, characterized in that: The control box also includes: The upper and lower bridge selection module is used to turn on the upper bridge arm switch group when the upper and lower bridge arm types contained in the test instruction are upper bridge arms, and to turn on the lower bridge arm switch group when the upper and lower bridge arm types contained in the test instruction are lower bridge arms.

7. The surge voltage test circuit according to claim 2, characterized in that: The control box also includes voltage probes connected to the collector and emitter of the insulated gate bipolar transistor respectively; and The test start module is used to send a single pulse signal to the gate of the insulated gate bipolar transistor after controlling the switches in the bridge arm selection switch group and the upper and lower bridge selection switch groups to close, and then detect the voltage waveform obtained by the voltage probe and send it to the host computer for test pass judgment.

8. A surge voltage testing method for a rectifier bridge module, characterized in that: A surge voltage test circuit as claimed in any one of claims 1 to 7, comprising: Step S1, the control box controls the switches in the bridge arm selection switch group to close according to an external test instruction to select the corresponding bridge arm as the bridge arm to be tested; Step S2, the control box controls the switches in the upper and lower bridge selection switch group to close according to the external test instruction so as to connect the upper bridge arm or the lower bridge arm of the bridge arm to be tested with the surge generation circuit to form a test loop; Step S3, the control box sends a pulse to the surge generating circuit to generate a surge voltage, and detects the voltage waveform and sends it to the host computer for test passing judgment.

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