Power module test circuit and test method

Abstract

The present application provides a power module test circuit and test method, belonging to the field of battery technology. The power module test circuit includes: a first power module group, connected to a power source, including multiple first power modules, configured to be connected in parallel with each other; a second power module group, including multiple second power modules, configured to be connected in parallel with each other, wherein the multiple second power modules correspond one-to-one with the multiple first power modules, and each of the multiple second power modules is respectively connected to a corresponding first power module; and a switching element, connected between the first power module group and the second power module group, configured to selectively isolate the second power module group from the first power module group. This test circuit can improve the flexibility of the testing process and reduce testing costs.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a test circuit and a test method for a power module. Background Art

[0002] Energy conservation and emission reduction are key to sustainable social development. Rechargeable batteries, with their ability to store and release energy as needed, are widely used in various electrical devices and energy storage systems, playing a crucial role in promoting energy transformation and sustainable development. Battery technology is a crucial factor in the development of the new energy industry.

[0003] Currently, rechargeable batteries are widely used in energy storage systems. With the large-scale application of energy storage systems, the performance and reliability of the power conversion system (PCS), the core device for achieving bidirectional conversion of electrical energy in energy storage systems, have a significant impact on the operational stability of the energy storage system. As a core component of the PCS, the performance of the power module is crucial to the overall efficiency of the energy storage system. By conducting relevant testing on power modules, design flaws in the power modules can be identified promptly, providing technical support for the safe and long-life operation of energy storage systems. However, current testing methods for power modules are relatively simple and the testing costs are high. Summary of the Invention

[0004] The present application aims to at least solve the technical problem of a single power module test method in the background art. To this end, one object of the present application is to provide a power module test circuit to improve the flexibility of the test process and reduce the test cost.

[0005] An embodiment of the first aspect of the present application provides a test circuit for a power module, comprising: a first power module group, connected to a power supply, comprising a plurality of first power modules, the plurality of first power modules being configured to be connected in parallel with each other; a second power module group, comprising a plurality of second power modules, the plurality of second power modules being configured to be connected in parallel with each other, wherein the plurality of second power modules correspond one-to-one to the plurality of first power modules, and each of the plurality of second power modules is respectively connected to a corresponding first power module; a switching element, connected between the first power module group and the second power module group, and configured to selectively isolate the second power module group from the first power module group.

[0006] In the technical solution of the embodiment of the present application, a switching element is set between the two power module groups, and the topology of the test circuit can be changed according to the number of power modules to be tested. While increasing the number of power modules tested each time, the number of times the test circuit and test equipment are replaced is reduced, thereby reducing the test cost and improving the test efficiency.

[0007] In some embodiments, each of the plurality of first power modules includes a power connection point, and the switch element is configured to selectively connect the power connection points of the plurality of first power modules to one another. By connecting the power connection points in the first power modules, the second power module group can be isolated from the first power module group, thereby flexibly changing the topology of the test circuit and enabling testing of different numbers of power modules.

[0008] In some embodiments, each of the plurality of first power modules includes a first insulated gate bipolar transistor and a second insulated gate bipolar transistor connected in series, and the power connection point is configured to be located between the first and second insulated gate bipolar transistors. Positioning the power connection point between the two insulated gate bipolar transistors allows testing of the first power module group by connecting the respective power connection points, thereby increasing the testing flexibility of the test circuit.

[0009] In some embodiments, the test circuit further includes: a plurality of inductors corresponding one-to-one to the plurality of second power modules, each of the plurality of inductors being connected between a corresponding second power module and the first power module corresponding to the second power module. Providing the inductors between the first power module and the second power module can suppress sudden current fluctuations in the test circuit, reducing the risk of abnormalities in individual components in the circuit due to excessive current.

[0010] In some embodiments, each of the plurality of second power modules includes a third insulated gate bipolar transistor and a fourth insulated gate bipolar transistor connected in series. Each of the plurality of inductors is configured to be connected between a first end of the third insulated gate bipolar transistor in the corresponding second power module and a power connection point in the first power module corresponding to the second power module, with the first end of the third insulated gate bipolar transistor connected to the fourth insulated gate bipolar transistor. By properly designing the connection positions of the inductors, the topology of the test circuit can be switched, enabling testing of both the first and second power modules.

[0011] In some embodiments, the test circuit further includes: a first capacitor connected in parallel with the first power module group, the capacitance of the first capacitor being determined based on a preset test voltage; and a second capacitor connected in parallel with the second power module group, the capacitance of the second capacitor being determined based on the test voltage. The inclusion of the capacitor in the test circuit ensures that the voltage applied to the power components meets test requirements, thereby improving the accuracy of the test results.

[0012] In some embodiments, the test circuit further includes a resistor element connected in parallel with the first power module group, the resistor element being configured to suppress an oscillation signal in the test circuit. Providing the resistor element in the test circuit can increase the damping of the test circuit, thereby suppressing the oscillation signal in the circuit.

[0013] In some embodiments, the test circuit further includes an energy storage element connected in parallel with the second power module group, the energy storage element being configured to store the electrical energy transmitted by the second power module group. Providing the energy storage element in parallel with the second power module group in the test circuit can store the electrical energy used during the test, thereby reducing power loss during the test and saving testing costs.

[0014] The second embodiment of the present application provides a power module testing method, which is used for the power module test circuit in the above embodiment, including: controlling the switch element to isolate or not isolate the second power module group from the first power module group; controlling the first power module group to convert the DC power output by the power supply into AC power; testing multiple first power modules in the first power module group; in response to the second power module group being not isolated from the first power module group: controlling the second power module group to convert the AC power converted by the first power module group into DC power; and testing multiple second power modules in the second power module group. By controlling the switch element, the topology of the test circuit can be switched, and the first power module and / or the second power module can be tested according to the test requirements, thereby improving test flexibility, reducing test costs, and improving test efficiency.

[0015] In some embodiments, each of the plurality of first power modules includes a power connection point, and controlling the switch element to isolate or not isolate the second power module group from the first power module group includes: controlling the switch element to connect the power connection points in the plurality of first power modules to isolate the second power module group from the first power module group; or controlling the switch element to disconnect the power connection points in the plurality of first power modules to not isolate the second power module group from the first power module group. Controlling the switch element to connect or not connect the power connection points in the first power modules can isolate or not isolate the second power module group from the first power module group, thereby flexibly changing the topology of the test circuit and implementing testing of different numbers of power modules.

[0016] In some embodiments, testing multiple first power modules in the first power module group includes: adjusting the effective value of the current flowing through any one of the multiple first power modules; in response to the effective value of the current flowing through any one of the multiple first power modules reaching a first current value, testing the multiple first power modules for a first time period; in response to the effective value of the current flowing through any one of the multiple first power modules reaching a second current value, testing the multiple first power modules for a second time period; and in response to the effective value of the current flowing through any one of the multiple first power modules reaching a third current value, testing the multiple first power modules for a third time period. By testing the first power modules at different current values, relevant performance parameters of the first power modules can be fully obtained, design defects can be identified in a timely manner, and testing results can be improved.

[0017] In some embodiments, testing the plurality of second power modules in the second power module group includes: adjusting the effective value of the current flowing through any one of the plurality of second power modules; in response to the effective value of the current flowing through any one of the plurality of second power modules reaching a fourth current value, testing the plurality of second power modules for a fourth time period; in response to the effective value of the current flowing through any one of the plurality of second power modules reaching a fifth current value, testing the plurality of second power modules for a fifth time period; and in response to the effective value of the current flowing through any one of the plurality of second power modules reaching a sixth current value, testing the plurality of second power modules for a sixth time period. By testing the second power modules at different current values, relevant performance parameters of the second power modules can be fully obtained, design defects can be identified in a timely manner, and testing results can be improved.

[0018] In some embodiments, each of the plurality of first power modules includes a first insulated gate bipolar transistor and a second insulated gate bipolar transistor connected in series. Controlling the first power module group to convert the DC power output by the power supply into AC power includes: setting a switching frequency of the first and second insulated gate bipolar transistors to a first switching frequency; and controlling the first and second insulated gate bipolar transistors to turn on or off at the first switching frequency to convert the DC power output by the power supply into AC power. By setting the switching frequency of the two insulated gate bipolar transistors, an inverter control logic can be implemented to convert the DC power output by the power supply into AC power, thereby achieving electrical energy conversion.

[0019] In some embodiments, the testing method further includes: after testing the plurality of first power modules in the first power module group: setting the switching frequency of the first insulated gate bipolar transistor and the second insulated gate bipolar transistor to a second switching frequency; and controlling the first insulated gate bipolar transistor and the second insulated gate bipolar transistor to be turned on or off at the second switching frequency to convert the direct current output by the power supply into alternating current. By testing the first power modules at different switching frequencies, relevant performance parameters of the first power modules can be fully obtained, design defects can be identified promptly, and testing results can be improved.

[0020] In some embodiments, each of the plurality of second power modules includes a third insulated gate bipolar transistor and a fourth insulated gate bipolar transistor connected in series. Controlling the second power module group to convert the AC power converted by the first power module group into DC power includes: setting a switching frequency of the third and fourth insulated gate bipolar transistors to a third switching frequency; and controlling the third and fourth insulated gate bipolar transistors to turn on or off at the third switching frequency to convert the AC power converted by the first power module group into DC power. By setting the switching frequency of the two insulated gate bipolar transistors, rectification control logic can be implemented to convert the AC power output by the first power module group into DC power, thereby achieving electrical energy conversion.

[0021] In some embodiments, the testing method further includes: after testing the plurality of second power modules in the second power module group: setting the switching frequency of the third and fourth insulated gate bipolar transistors to a fourth switching frequency; and controlling the third and fourth insulated gate bipolar transistors to be turned on or off at the fourth switching frequency to convert the alternating current (AC) power converted by the first power module group into direct current (DC). By testing the second power modules at different switching frequencies, relevant performance parameters of the second power modules can be fully obtained, design defects can be identified promptly, and testing results can be improved.

[0022] In some embodiments, the test circuit further includes an energy storage element connected in parallel with the second power module group, and the testing method further includes: controlling the energy storage element to store the direct current converted by the second power module group. Using the energy storage element to store the electrical energy used during the test process can reduce power loss during the test process and save testing costs.

[0023] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar components or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0025] Figure 1 A schematic diagram of a test circuit for a power module according to some embodiments of the present application;

[0026] Figure 2 A schematic diagram of a test circuit for a power module according to some embodiments of the present application;

[0027] Figure 3 A schematic diagram of the connection relationship between the first power module group and the second power module group in some embodiments of the present application;

[0028] Figure 4 A schematic flow chart of a power module testing method according to some embodiments of the present application;

[0029] Figure 5 This is a schematic diagram of a flow chart of controlling the isolation or non-isolation of a first power module group and a second power module group in some embodiments of the present application;

[0030] Figure 6 This is a schematic diagram of a process for testing a first power module according to some embodiments of the present application;

[0031] Figure 7 This is a schematic diagram of a process for testing a second power module according to some embodiments of the present application;

[0032] Figure 8 This is a schematic diagram of a flow chart of controlling a first power module group to convert direct current into alternating current in some embodiments of the present application;

[0033] Figure 9 This is a schematic diagram of a flow chart of controlling a first power module group to convert direct current into alternating current in some embodiments of the present application;

[0034] Figure 10 A schematic diagram of a flow chart of controlling the second power module group to convert alternating current into direct current in some embodiments of the present application;

[0035] Figure 11 This is a schematic diagram of a flow chart of controlling the second power module group to convert alternating current into direct current according to some embodiments of the present application. DETAILED DESCRIPTION

[0036] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0038] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0039] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0040] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0041] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0042] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0043] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0044] Currently, market developments indicate that rechargeable batteries are becoming increasingly widely used. They are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but are also widely used in various electronic devices, including electric vehicles like electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. As the application areas of rechargeable batteries continue to expand, market demand is also growing.

[0045] Currently, rechargeable batteries are widely used in energy storage systems. With the large-scale application of energy storage systems, the performance and reliability of the power conversion system (PCS), the core device for achieving bidirectional conversion of electrical energy in energy storage systems, have a significant impact on the operational stability of the energy storage system. As the core component of the PCS, the power module undertakes the PCS's main functions, such as AC / DC conversion, voltage regulation, and power control. The power module's dynamic response characteristics, thermal management capabilities, and long-term operational reliability are crucial to the overall efficiency of the energy storage system. By conducting relevant testing on the power module, design flaws in the power module can be identified promptly, providing technical support for the safe and long-life operation of the energy storage system.

[0046] However, current testing methods for power modules are relatively limited, typically only testing a single power module and lacking test circuits for multiple power modules. As the number of power modules to be tested increases, the test circuits and equipment must be replaced, resulting in high testing costs.

[0047] To improve the flexibility of the testing process, a switch element can be installed between the two power module groups. The switch element can control whether the two power module groups are isolated from each other. When the two power module groups are isolated from each other, only the power modules in one power module group can be tested. When the two power module groups are not isolated from each other, the power modules in both power module groups can be tested.

[0048] Using such a test circuit, different circuit topologies can be selected for different numbers of power modules to be tested without having to replace the test circuit and test equipment, effectively reducing test costs.

[0049] The power module test circuit disclosed in the embodiments of this application can be used, but is not limited to, in the testing process of power modules used in electrical devices or energy storage devices such as vehicles, ships, or aircraft. Using the power module test circuit disclosed in this application can improve the flexibility of the power module testing process and reduce testing costs.

[0050] The present application embodiment provides a test circuit for a power module. Figure 1 The power module test circuit 100 includes a first power module group 110 , a second power module group 120 and a switching element 130 .

[0051] The first power module group 110 is connected to the power source 10 and includes a plurality of first power modules 111. The plurality of first power modules 111 are configured to be connected in parallel with each other.

[0052] The second power module group 120 includes a plurality of second power modules 121. The plurality of second power modules 121 are configured to be connected in parallel with each other. The plurality of second power modules 121 correspond one-to-one to the plurality of first power modules 111. Each second power module 121 in the plurality of second power modules 121 is connected to a corresponding first power module 111.

[0053] The switching element 130 is connected between the first power module group 110 and the second power module group 120 and is configured to selectively isolate the second power module group 120 from the first power module group 110 .

[0054] In the embodiments of the present application, the power module can realize the conversion and control of electric energy, for example, it can realize the conversion of AC and DC, voltage regulation, power control and other functions, and is suitable for various power electronics applications, such as energy storage systems, solar and wind energy converters, electric vehicle control, etc. In one example, the power module can be used in the energy storage converter PCS of the energy storage system. The PCS can control the charging and discharging process of the rechargeable battery and perform AC / DC conversion. The power module is the main component of the PCS.

[0055] During use, power modules are subject to multiple stresses, including high-frequency switching, complex power grid fluctuations, and extreme temperature fluctuations. Electrical parameter drift, component aging, and thermal failure can lead to performance degradation or even system failure. Test circuit 100 can be used to test power modules. By performing various tests on power modules, design flaws can be identified, enabling improvements to the module's design.

[0056] like Figure 1 As shown, the test circuit 100 includes two power module groups, namely a first power module group 110 and a second power module group 120. Each power module group is provided with a plurality of power modules, and the performance of these power modules can be tested. The first power module 111 and the second power module 121 can use the same power module or different power modules. Figure 1 In the example shown, each power module group includes three power modules connected in parallel. The three first power modules 111 (i.e., first power module 111-a, first power module 111-b, first power module 111-c) in the first power module group 110 and the three second power modules 121 (i.e., second power module 121-a, second power module 121-b, second power module 121-c) in the second power module group 120 correspond one to one. The corresponding first power modules 111 and second power modules 121 are connected together, as shown in FIG. Figure 1 The first power module 111 - a is connected to the second power module 121 - a , the first power module 111 - b is connected to the second power module 121 - b , and the first power module 111 - c is connected to the second power module 121 - c .

[0057] The first power module group 110 is connected to the power supply 10 and can receive the power output by the power supply 10 for testing the power module. In some embodiments, the power supply 10 can use a direct current power supply.

[0058] A switch element 130 is also provided between the first power module group 110 and the second power module group 120. Switch element 130 controls whether the two power module groups are isolated from each other. When the second power module group 120 is not isolated from the first power module group 110, the first power module group 110 can transfer power to the second power module group 120, thereby enabling the power modules in both power module groups to be tested using the power output from the battery. When the second power module group 120 is isolated from the first power module group 110, the power output from the first power module group 110 will not be transferred to the second power module group 120, and the power output from the battery will only be used to test the first power module 111 in the first power module group 110.

[0059] By setting a switching element between the two power module groups, the topology of the test circuit can be changed according to the number of power modules to be tested. While increasing the number of power modules tested each time, the number of times the test circuit and test equipment are replaced can be reduced, thereby reducing test costs and improving test efficiency.

[0060] According to some embodiments of the present application, reference Figure 2 Each of the plurality of first power modules 111 includes a power connection point A. The switching element 130 is configured to selectively connect the power connection points A of the plurality of first power modules 111 to each other.

[0061] like Figure 2 As shown, the power module may be a power half-bridge module, that is, a power electronic device module integrating two insulated gate bipolar transistors (IGBTs) and supporting circuits. Figure 2 T1 and T4 in Figure 1 The two IGBTs integrated in the first power module 111-a shown in the figure, T2 and T5 are the two IGBTs integrated in the first power module 111-b, T3 and T6 are the two IGBTs integrated in the first power module 111-c, T7 and T10 are the two IGBTs integrated in the second power module 121-c, T8 and T11 are the two IGBTs integrated in the second power module 121-b, and T9 and T12 are the two IGBTs integrated in the second power module 121-a.

[0062] In each first power module 111, a power connection point A is provided. The switch element 130 can control whether the power connection points A are connected to each other. Figure 2As shown, when the three power connection points A are not connected to each other, the second power module group 120 is not isolated from the first power module group 110, and each first power module 111 in the first power module group 110 will be connected to the corresponding second power module 121 in the second power module group 120, thereby forming the following Figure 3 The circuit topology shown above is a structure in which the second power module group 120 is not isolated from the first power module group 110. In this case, the first power module group 110 transmits power to the second power module group 120, and the three first power modules 111 and the three second power modules 121 can be tested. When the three power connection points A are connected to each other, the three first power modules 111 are short-circuited to each other, and the first power module group 110 will not transmit power to the second power module group 120, thereby isolating the second power module group 120 from the first power module group 110. When the three power connection points A are connected to each other, a circuit topology can be formed as shown in FIG. Figure 3 The circuit topology shown below is when the second power module group 120 is isolated from the first power module group 110. In this case, only the three first power modules 111 will be tested.

[0063] In some embodiments, the switch element 130 may include a relay. When the relay is closed, the power connection points A in the first power modules 111 are connected to each other, thereby short-circuiting the plurality of first power modules 111 to each other.

[0064] By connecting the power connection points in the first power module, the second power module group can be isolated from the first power module group, so that the topology of the test circuit can be flexibly changed to achieve testing of different numbers of power modules.

[0065] According to some embodiments of the present application, reference Figure 2 Each of the plurality of first power modules 111 includes a first insulated gate bipolar transistor and a second insulated gate bipolar transistor connected in series. The power connection point A is configured to be located between the first insulated gate bipolar transistor and the second insulated gate bipolar transistor.

[0066] like Figure 2 As shown, each first power module 111 includes two IGBTs, and the power connection point A is set between the two IGBTs, that is, the power connection point A in the first power module 111-a is set between the first insulated gate bipolar transistor T1 and the second insulated gate bipolar transistor T4, the power connection point A in the first power module 111-b is set between the first insulated gate bipolar transistor T2 and the second insulated gate bipolar transistor T5, and the power connection point A in the first power module 111-c is set between the first insulated gate bipolar transistor T3 and the second insulated gate bipolar transistor T6.

[0067] The power connection point is set between the two insulated gate bipolar transistors. The first power module group can be tested by connecting the power connection points, thereby improving the test flexibility of the test circuit.

[0068] According to some embodiments of the present application, reference Figure 2 , the test circuit 100 further includes a plurality of inductive elements.

[0069] The plurality of inductance elements correspond one-to-one to the plurality of second power modules 121. Each of the plurality of inductance elements is connected between a corresponding second power module 121 and a first power module 111 corresponding to the second power module 121.

[0070] like Figure 2 As shown, the test circuit 100 also includes inductors L1, L2, and L3. An inductor is provided between each first power module 111 and its corresponding second power module 121. Inductor L3 is connected between the corresponding first power module 111-a and second power module 121-a, inductor L2 is connected between the corresponding first power module 111-b and second power module 121-b, and inductor L1 is connected between the corresponding first power module 111-c and second power module 121-c.

[0071] During the use of power modules, each IGBT will frequently switch between on and off states. During this switching, current spikes will be generated. The instantaneous high current value may cause damage to components in the circuit. Inductors can suppress current spikes.

[0072] In some embodiments, a plurality of inductive elements may be provided between each first power module 111 and the switching element 130. Figure 2 As shown, the inductor element L3 is connected between the first power module 111-a and the switch element 130, the inductor element L2 is connected between the first power module 111-b and the switch element 130, and the inductor element L1 is connected between the first power module 111-c and the switch element 130. In this way, when the switch element 130 isolates the second power module group 120 from the first power module group 110 (for example, forming Figure 3 In the circuit topology in which the second power module group is isolated from the first power module group shown below), the inductor element can still suppress the current spike in the circuit.

[0073] Providing an inductor between the first power module and the second power module can suppress sudden current changes in the test circuit and reduce the risk of abnormalities in various components in the circuit due to excessive current.

[0074] According to some embodiments of the present application, reference Figure 2 Each of the plurality of second power modules 121 includes a third insulated gate bipolar transistor and a fourth insulated gate bipolar transistor connected in series.

[0075] Each of the plurality of inductance elements is configured to be connected between a first terminal B of a third insulated gate bipolar transistor in a corresponding second power module 121 and a power connection point A in a first power module 111 corresponding to the second power module 121. The first terminal B of the third insulated gate bipolar transistor is connected to a fourth insulated gate bipolar transistor.

[0076] like Figure 2 As shown, each second power module 121 includes two IGBTs. T7, T8 and T9 can be considered as third insulated gate bipolar transistors, and T10, T11 and T12 can be considered as fourth insulated gate bipolar transistors. The first terminal B of the third insulated gate bipolar transistor is the terminal where the third insulated gate bipolar transistor is connected to the fourth insulated gate bipolar transistor. Each inductor element is respectively connected between the power connection point A of the first power module 111 and the first terminal B of the third insulated gate bipolar transistor in the second power module 121. Figure 2 In the example shown, the inductor element L3 is connected between the power connection point A in the first power module 111-a and the first end B of the third insulated gate bipolar transistor T9 in the second power module 121-a, the inductor element L2 is connected between the power connection point A in the first power module 111-b and the first end B of the third insulated gate bipolar transistor T8 in the second power module 121-b, and the inductor element L1 is connected between the power connection point A in the first power module 111-c and the first end B of the third insulated gate bipolar transistor T7 in the second power module 121-c.

[0077] By properly designing the connection position of the inductor element, the topology of the test circuit can be switched, so that the test of the first power module and the second power module can be completed.

[0078] According to some embodiments of the present application, reference Figure 2 , the test circuit 100 further includes a first capacitive element C1 and a second capacitive element C2.

[0079] The first capacitor element C1 is connected in parallel with the first power module group 110. The capacitance of the first capacitor element C1 is determined according to a preset test voltage.

[0080] The second capacitor element C2 is connected in parallel with the second power module group 120. The capacitance of the second capacitor element C2 is determined according to the test voltage.

[0081] like Figure 2 As shown, the test circuit 100 is also provided with a first capacitor element C1 and a second capacitor element C2, which can play the role of supporting capacitors, that is, they can filter the voltage in the circuit and reduce the voltage fluctuation in the circuit. The first capacitor element C1 is connected in parallel with the first power module group 110, and its capacitance can be determined according to the test voltage of the first power module 111, so that the voltage on the first power module 111 can reach the preset test voltage during the test. The second capacitor element C2 is connected in parallel with the second power module group 120, and its capacitance can be determined according to the test voltage of the second power module 121, so that the voltage on the second power module 121 can reach the preset test voltage during the test. Figure 2 In the example shown using a power half-bridge module, the capacitance of the capacitor element can be determined according to a predetermined bridge arm voltage.

[0082] Providing a capacitor element in the test circuit can ensure that the voltage applied to the power element meets the test requirements and improve the accuracy of the test results.

[0083] According to some embodiments of the present application, reference Figure 2 , the test circuit 100 further includes a resistance element R1.

[0084] The resistor R1 is connected in parallel with the first power module group 110 . The resistor R1 is used to suppress an oscillation signal in the test circuit 100 .

[0085] like Figure 2 As shown, the test circuit 100 is also provided with a resistor element R1 connected in parallel with the first power module group 110. During the test process, the IGBT in the power module will switch between on / off states at a certain frequency. Parasitic oscillations may exist in the test circuit 100, that is, an oscillation signal that is inconsistent with the operating frequency. It can also be understood as an oscillation signal that is unrelated to the switching frequency of the IGBT or is not within the switching frequency range of the IGBT due to parasitic parameters in the circuit. The resistor element R1 can increase the damping of the test circuit 100, so that the parasitic oscillation signal is dissipated due to greater resistance.

[0086] Providing a resistance element in the test circuit can increase the damping of the test circuit and suppress the oscillation signal in the circuit.

[0087] According to some embodiments of the present application, reference Figure 2 , the test circuit 100 further includes an energy storage element R2.

[0088] The energy storage element R2 is connected in parallel with the second power module group 120. The energy storage element R2 is used to store the electric energy transmitted by the second power module group 120.

[0089] like Figure 2 As shown, energy storage element R2 is connected in parallel with the second power module group 120. The power output by the second power module group 120 can be transmitted to energy storage element R2. In some embodiments, energy storage element R2 can use an energy storage battery. After receiving the power transmitted by the second power module group 120, the energy storage battery can store the power and apply the power to other use scenarios.

[0090] An energy storage element connected in parallel with the second power module group is provided in the test circuit to store the electric energy used in the test process, thereby reducing the power loss in the test process and saving the test cost.

[0091] Based on the same technical concept, the embodiment of the present application provides a power module testing method, which is used for the power module testing circuit 100 in the above embodiment. The embodiment of the power module testing method can refer to the embodiment of the power module testing circuit 100, and the repeated parts will not be repeated. Figure 4 The power module testing method 400 includes steps 410 to 450 .

[0092] In step 410 , the switch element 130 is controlled to isolate or not isolate the second power module group 120 from the first power module group 110 .

[0093] Step 420 : Control the first power module group 110 to convert the direct current output by the power supply 10 into alternating current.

[0094] Step 430 : Testing the plurality of first power modules 111 in the first power module group 110 .

[0095] In response to the second power module group 120 not being isolated from the first power module group 110:

[0096] Step 440 : Control the second power module group 120 to convert the AC power converted by the first power module group 110 into DC power.

[0097] Step 450 : Testing the plurality of second power modules 121 in the second power module group 120 .

[0098] As described above, switch element 130 can isolate the two power module groups. In step 410, switch element 130 can be controlled based on test requirements. In one example, when all power modules in both power module groups need to be tested, switch element 130 can be controlled to maintain isolation between second power module group 120 and first power module group 110. However, when only first power module 111 in first power module group 110 needs to be tested, switch element 130 can be controlled to isolate second power module group 120 from first power module group 110.

[0099] In some embodiments, how to control the switch element 130 can be determined according to the number of power modules to be tested. Figure 2 Taking the example in which each power module group includes 3 power modules as an example, if the number of power modules to be tested does not exceed three, the power module to be tested can be used as the first power module 111 and set in the first power module group 110. During the test, the control switch element 130 isolates the second power module group 120 from the first power module group 110, so that only the first power module 111 in the first power module group 110 can be tested; if the number of power modules to be tested exceeds three, the power modules to be tested can be respectively set in the first power module group 110 and the second power module group 120, and the control switch element 130 does not isolate the second power module group 120 from the first power module group 110, so that both the first power module 111 in the first power module group 110 and the second power module 121 in the second power module group 120 can be tested.

[0100] In step 420, the first power module 111 in the first power module group 110 can be controlled to perform AC / DC conversion to implement an inverter function, that is, to convert the DC power output by the power supply 10 into AC power. In step 430, the first power module 111 in the first power module group 110 can be tested. Test parameters and test items can be determined according to different needs. For example, the bridge arm current, capacitor current, voltage stress of each IGBT, device temperature, etc. in the power module can be tested, and this application does not limit this.

[0101] When the second power module group 120 is not isolated from the first power module group 110, the second power module 121 will also be tested. In step 440, the second power module 121 in the second power module group 120 can be controlled to perform AC-DC conversion to achieve a rectification function, that is, to convert the AC power output by the first power module group 110 into DC power. In step 450, the second power module 121 in the second power module group 120 can be tested. Test parameters and test items can be determined according to different requirements. For example, the bridge arm current, capacitor current, voltage stress of each IGBT, device temperature, etc. in the power module can be tested, and this application does not limit this.

[0102] By controlling the switching elements, the topology of the test circuit can be switched, and the first power module and / or the second power module can be tested according to the test requirements, thereby improving test flexibility, reducing test costs, and improving test efficiency.

[0103] According to some embodiments of the present application, reference Figure 5 , step 410 includes step 510 or step 520.

[0104] In step 510 , the switch element 130 is controlled to connect the power connection points A in the plurality of first power modules 111 to each other, so that the second power module group 120 is isolated from the first power module group 110 .

[0105] In step 520 , the switch element 130 is controlled to disconnect the power connection points A in the plurality of first power modules 111 from each other, so that the second power module group 120 is not isolated from the first power module group 110 .

[0106] As described above, when the power connection points A in the first power module 111 are connected, the second power module group 120 is isolated from the first power module group 110, and the first power module group 110 does not transmit power to the second power module group 120. When the power connection points A in the first power module 111 are disconnected, the second power module group 120 is not isolated from the first power module group 110, and the first power module group 110 transmits power to the second power module group 120.

[0107] By controlling the switch element to connect or disconnect the power connection point in the first power module, the second power module group and the first power module group can be isolated or not, thereby flexibly changing the topology of the test circuit and realizing testing of different numbers of power modules.

[0108] According to some embodiments of the present application, reference Figure 6 , step 430 includes steps 610 to 640.

[0109] Step 610 : Adjust the effective value of the current flowing through any first power module 111 among the plurality of first power modules 111 .

[0110] Step 620 : In response to the effective value of the current flowing through any one of the plurality of first power modules 111 reaching a first current value, testing the plurality of first power modules 111 within a first time period.

[0111] Step 630 : In response to the effective value of the current flowing through any one of the plurality of first power modules 111 reaching a second current value, testing the plurality of first power modules 111 within a second time period.

[0112] Step 640 : In response to the effective value of the current flowing through any one of the plurality of first power modules 111 reaching a third current value, testing the plurality of first power modules 111 within a third time period.

[0113] In step 610, the effective value of the current flowing through each first power module 111 can be adjusted. Figure 2 In the example of using a power half-bridge module, this can also be understood as adjusting the effective value of the bridge arm current. In some embodiments, the effective value of the current flowing through the first power module 111 can be adjusted to gradually increase at a certain slope. This can be achieved by adjusting the capacitance of the capacitors (C1, C2, etc.) and the inductance of the inductors (L1, L2, L3, etc.).

[0114] The first current value, the second current value, and the third current value can be predetermined based on the performance of the power module to be tested. In some embodiments, the second current value can be set to be greater than the first current value, and the third current value can be set to be greater than the second current value. For example, the first current value, the second current value, and the third current value can be set to 1000A (amperes), 1500A, and 2000A, respectively.

[0115] The first duration, the second duration, and the third duration can be preset according to the requirements of the test process, and can be set to the same duration or different durations.

[0116] As the test progresses, the effective value of the current flowing through the first power module 111 will gradually increase. When the effective value of the current reaches the preset first current value I1, the first power module 111 can be tested within a first time period. For example, when the effective value of the current flowing through the first power module 111 reaches the first current value I1, after the current waveform stabilizes, the test circuit 100 can be used to conduct uninterrupted testing for 2 hours. Within 2 hours, various performance indicators of the first power module 111 can be tested, such as the bridge arm current, capacitor current, voltage stress of each IGBT, device temperature, etc.

[0117] If the RMS current reaches the first current value I1 and the various performance indicators of the first power module 111 meet the requirements, the RMS current can be further increased. For example, the capacitance of the capacitors (C1, C2, etc.) and the inductance of the inductors (L1, L2, L3, etc.) can be adjusted. As the test progresses, the RMS current flowing through the first power module 111 will gradually increase. When the RMS current reaches a pre-set second current value I2, the first power module 111 can be tested for a second duration. For example, when the RMS current flowing through the first power module 111 reaches the second current value I2 and the current waveform stabilizes, the test circuit 100 can be used to conduct uninterrupted testing for two hours, and the various performance indicators of the first power module 111 can be tested within two hours.

[0118] If the performance indicators of the first power module 111 meet the requirements when the effective current reaches the second current value I2, the effective current can be further increased. For example, the capacitance of the capacitors (C1, C2, etc.) and the inductance of the inductors (L1, L2, L3, etc.) can be adjusted. As the test progresses, the effective current flowing through the first power module 111 will gradually increase. When the effective current reaches a predetermined third current value I3, the first power module 111 can be tested for a third duration. For example, when the effective current flowing through the first power module 111 reaches the third current value I3 and the current waveform stabilizes, the test circuit 100 can be used to conduct continuous testing for two hours, and the various performance indicators of the first power module 111 can be tested within two hours.

[0119] By testing the first power module at different current values, relevant performance parameters of the first power module can be fully acquired, design defects can be identified in a timely manner, and the test effect can be improved.

[0120] According to some embodiments of the present application, reference Figure 7 , step 450 includes steps 710 to 740.

[0121] Step 710 : Adjust the effective value of the current flowing through any second power module 121 among the plurality of second power modules 121 .

[0122] Step 720 : In response to the effective value of the current flowing through any second power module 121 among the plurality of second power modules 121 reaching a fourth current value, testing the plurality of second power modules 121 within a fourth time period.

[0123] Step 730 : In response to the effective value of the current flowing through any second power module 121 among the plurality of second power modules 121 reaching a fifth current value, testing the plurality of second power modules 121 within a fifth time period.

[0124] Step 740 : In response to the effective value of the current flowing through any second power module 121 among the plurality of second power modules 121 reaching a sixth current value, testing the plurality of second power modules 121 within a sixth time period.

[0125] Similar to the test on the first power module 111, in step 710, the effective value of the current flowing through each second power module 121 can be adjusted. Figure 2 In the example of using a power half-bridge module, this can also be understood as adjusting the effective value of the bridge arm current. In some embodiments, the effective value of the current flowing through the second power module 121 can be adjusted to gradually increase at a certain slope. This can be achieved by adjusting the capacitance of the capacitors (C1, C2, etc.) and the inductance of the inductors (L1, L2, L3, etc.).

[0126] The fourth current value, the fifth current value, and the sixth current value can be predetermined based on the performance of the power module to be tested. In some embodiments, the fifth current value can be set to be greater than the fourth current value, and the sixth current value can be set to be greater than the fifth current value. In some embodiments, the fourth current value can be equal to the first current value, the fifth current value can be equal to the second current value, and the sixth current value can be equal to the third current value. For example, the fourth current value, the fifth current value, and the sixth current value can be set to 1000A, 1500A, and 2000A, respectively.

[0127] The fourth duration, the fifth duration, and the sixth duration can be pre-set according to the requirements of the test process, and can be set to the same duration or different durations. In some embodiments, the fourth duration can be equal to the first duration, the fifth duration can be equal to the second duration, and the sixth duration can be equal to the third duration.

[0128] As the test progresses, the effective value of the current flowing through the second power module 121 will gradually increase. When the effective value of the current reaches the pre-set fourth current value I4, the second power module 121 can be tested within a fourth time period. For example, when the effective value of the current flowing through the second power module 121 reaches the fourth current value I4, after the current waveform stabilizes, the test circuit 100 can be used to conduct uninterrupted testing for 2 hours. Within 2 hours, various performance indicators of the second power module 121 can be tested, such as the bridge arm current, capacitor current, voltage stress of each IGBT, device temperature, etc.

[0129] If the performance indicators of the second power module 121 meet the requirements when the effective current reaches the fourth current value I4, the effective current can be further increased. For example, the capacitance of the capacitors (C1, C2, etc.) and the inductance of the inductors (L1, L2, L3, etc.) can be adjusted. As the test progresses, the effective current flowing through the second power module 121 will gradually increase. When the effective current reaches the preset fifth current value I5, the second power module 121 can be tested for a fifth time period. For example, when the effective current flowing through the second power module 121 reaches the fifth current value I5 and the current waveform stabilizes, the test circuit 100 can be used to conduct continuous testing for two hours, and the various performance indicators of the second power module 121 can be tested within two hours.

[0130] If the performance indicators of the second power module 121 meet the requirements when the effective current value reaches the fifth current value I5, the effective current value can be further increased. For example, the capacitance of the capacitors (C1, C2, etc.) and the inductance of the inductors (L1, L2, L3, etc.) can be adjusted. As the test progresses, the effective current value flowing through the second power module 121 will gradually increase. When the effective current value reaches the preset sixth current value I6, the second power module 121 can be tested for a sixth time period. For example, when the effective current value flowing through the second power module 121 reaches the sixth current value I6, after the current waveform stabilizes, the test circuit 100 can be used to conduct uninterrupted testing for two hours, and the various performance indicators of the second power module 121 can be tested within two hours.

[0131] In some embodiments, the tests on the first power module 111 and the second power module 121 may be performed simultaneously.

[0132] By testing the second power module at different current values, relevant performance parameters of the second power module can be fully obtained, design defects can be identified in a timely manner, and test results can be improved.

[0133] According to some embodiments of the present application, each of the plurality of first power modules 111 includes a first insulated gate bipolar transistor and a second insulated gate bipolar transistor connected in series. Figure 8 , step 420 includes steps 810 to 820.

[0134] Step 810 : Setting the switching frequency of the first insulated gate bipolar transistor and the second insulated gate bipolar transistor to a first switching frequency.

[0135] Step 820 , controlling the first insulated gate bipolar transistor and the second insulated gate bipolar transistor to be turned on or off at a first switching frequency, so as to convert the direct current output by the power supply 10 into alternating current.

[0136] As mentioned above, the first power module group 110 can convert the DC power output by the power supply 10 into AC power, that is, realize the inverter function. Figure 2 As shown, each first power module 111 includes two IGBTs, and the inverter function can be achieved by controlling these two IGBTs. In some embodiments, the state of the IGBT, that is, whether the IGBT is on or off, can be determined by a voltage signal applied to its control electrode. For example, a pulse width modulation signal (PWM) can be used to control the IGBT. When one IGBT is on and the others are off, the output voltage is positive; similarly, when one IGBT is on and the others are off, the output voltage is negative. By controlling each IGBT to turn on or off in turn at a certain frequency, the output voltage of the first power module group 110 will become an alternating square wave, realizing the conversion of direct current into alternating current. The frequency of the IGBT control signal determines the output frequency of the first power module group 110.

[0137] In some embodiments, the switching frequency of the first and second insulated gate bipolar transistors can be controlled by applying a control signal to the transistors, thereby converting the direct current output by the power supply 10 into alternating current and adjusting the frequency of the alternating current output by the first power module group 110.

[0138] In one example, the first switching frequency may be set to 250 Hz (Hertz).

[0139] By setting the switching frequency of the two insulated gate bipolar transistors, the inverter control logic can be realized to convert the direct current output of the power supply into alternating current, thereby realizing the conversion of electrical energy.

[0140] According to some embodiments of the present application, the testing method 400 further includes a first process 900 after step 430. Figure 9 , the first process 900 includes steps 910 to 920.

[0141] Step 910 : Setting the switching frequency of the first insulated gate bipolar transistor and the second insulated gate bipolar transistor to a second switching frequency.

[0142] Step 920 , controlling the first insulated gate bipolar transistor and the second insulated gate bipolar transistor to be turned on or off at a second switching frequency, so as to convert the direct current output by the power supply 10 into alternating current.

[0143] After completing the test of the first and second IGBTs at the first switching frequency, the IGBT switching frequency can be changed to further test various performance indicators of the power module after the switching frequency change. The switching frequencies of the first and second IGBTs are set to the second switching frequency, and the conversion of the DC power output by the power supply 10 into AC power continues. The frequency of the AC power output by the first power module group 110 is adjusted.

[0144] When the switching frequency is set to the second switching frequency, step 430 may be executed to test various performance indicators of the power module at the second switching frequency. For example, steps 610 to 640 mentioned above may be executed.

[0145] In some embodiments, the second switching frequency may be set to be greater than the first switching frequency. For example, the second switching frequency may be set to 300 Hz.

[0146] By testing the first power module at different switching frequencies, relevant performance parameters of the first power module can be fully acquired, design defects can be identified in a timely manner, and testing results can be improved.

[0147] According to some embodiments of the present application, reference Figure 10 , step 440 includes steps 1010 to 1020.

[0148] Step 1010: Set the switching frequency of the third insulated gate bipolar transistor and the fourth insulated gate bipolar transistor to a third switching frequency.

[0149] Step 1020 : Control the third insulated gate bipolar transistor and the fourth insulated gate bipolar transistor to be turned on or off at a third switching frequency, so as to convert the alternating current converted by the first power module group 110 into direct current.

[0150] The second power module group 120 is capable of converting AC power into DC power, that is, achieving a rectification function. Similar to the first power module group 110 mentioned above, as the reverse process of inversion, the rectification function can also be achieved by controlling the two IGBTs in the second power module 121. By controlling each IGBT to turn on or off at a certain frequency, the output voltage of the second power module group 120 will become DC power, achieving the conversion of AC power into DC power. In some embodiments, the third switching frequency can be set to be equal to the first switching frequency to achieve the conversion of AC power output by the first power module group 110 into DC power.

[0151] In some embodiments, the switching frequencies of the third and fourth insulated gate bipolar transistors can be controlled by applying control signals to the transistors, thereby converting the alternating current (AC) output by the first power module group 110 into direct current (DC).

[0152] In one example, the third switching frequency may be set to 250 Hz.

[0153] In some embodiments, steps 420 and 440 can be performed simultaneously, so that the first power module group 110 can convert the DC power output by the power supply 10 into AC power, and the second power module group 120 can further convert the AC power output by the first power module group 110 back into DC power. Accordingly, steps 430 and 450 can also be performed simultaneously.

[0154] By setting the switching frequency of the two insulated gate bipolar transistors, the rectification control logic can be realized to convert the alternating current output by the first power module group into direct current, thereby realizing the conversion of electric energy.

[0155] According to some embodiments of the present application, the testing method 400 further includes a second process 1100 after step 450. Figure 11 , the second process 1100 includes steps 1110 to 1120.

[0156] Step 1110 : setting the switching frequency of the third insulated gate bipolar transistor and the fourth insulated gate bipolar transistor to a fourth switching frequency.

[0157] Step 1120 , controlling the third insulated gate bipolar transistor and the fourth insulated gate bipolar transistor to be turned on or off at a fourth switching frequency, so as to convert the alternating current converted by the first power module group 110 into direct current.

[0158] Similar to the first power module group 110 mentioned above, after completing the test of the third and fourth IGBTs switching at the third switching frequency, the IGBT switching frequency can be changed to further test the various performance indicators of the power module after the switching frequency change. The switching frequency of the third and fourth IGBTs is set to the fourth switching frequency, and the AC power output from the first power module group 110 is continued to be converted into DC power.

[0159] When the switching frequency is set to the fourth switching frequency, step 450 may be executed to test various performance indicators of the power module at the second switching frequency. For example, steps 710 to 740 mentioned above may be executed.

[0160] In some embodiments, the fourth switching frequency may be set to be greater than the third switching frequency. For example, the fourth switching frequency may be set to 300 Hz.

[0161] In some embodiments, the fourth switching frequency may be set equal to the second switching frequency.

[0162] In some embodiments, the first process 900 and the second process 1100 can be performed simultaneously, so that the first power module group 110 can convert the direct current output by the power supply 10 into alternating current, and the second power module group 120 can further convert the alternating current output by the first power module group 110 back into direct current.

[0163] By testing the second power module at different switching frequencies, relevant performance parameters of the second power module can be fully obtained, design defects can be identified in a timely manner, and testing results can be improved.

[0164] According to some embodiments of the present application, the test circuit 100 further includes an energy storage element R2 connected in parallel with the second power module group 120. The test method 400 further includes: controlling the energy storage element R2 to store the DC power converted by the second power module group 120.

[0165] As described above, the energy storage element R2 can store the electric energy output by the second power module, so that the electric energy can be applied to other usage scenarios.

[0166] Using energy storage elements to store the electrical energy used in the test process can reduce power loss during the test process and save test costs.

[0167] A specific embodiment of the present application is described below. It should be understood that this specific embodiment is described for illustrative purposes only and should not be construed as limiting the present application.

[0168] like Figures 1 to 3 As shown, in a power module test circuit 100, a first power module group 110 and a second power module group 120 are provided. Each power module group includes multiple power modules connected in parallel. The power modules may be power half-bridge modules. A first power module 111 in the first power module group 110 corresponds to a second power module 121 in the second power module group 120. The corresponding first power modules 111 and second power modules 121 are connected together. A switching element 130 is also provided between the first power module group 110 and the second power module group 120. The switching element 130 can control whether the two power module groups are isolated from each other.

[0169] like Figure 2As shown, in each first power module 111, a power connection point A is respectively provided. Each first power module 111 includes two IGBTs, and the power connection point A is provided between the two IGBTs. The switching element 130 can control whether the power connection points A are connected to each other. When the multiple power connection points A are not connected to each other, the second power module group 120 is not isolated from the first power module group 110, and each first power module 111 in the first power module group 110 will be connected to the corresponding second power module 121 in the second power module group 120. The first power module group 110 transmits the electric energy output by the power supply 10 to the second power module group 120, and the multiple first power modules 111 and the multiple second power modules 121 can be tested. When multiple power connection points A are connected to each other, the multiple first power modules 111 are short-circuited with each other, and the first power module group 110 will not transmit electrical energy to the second power module group 120, thereby isolating the second power module group 120 from the first power module group 110, and only testing the multiple first power modules 111.

[0170] The test circuit 100 also includes an inductor. An inductor is provided between each first power module 111 and its corresponding second power module 121. Each inductor is connected between the power connection point A of the corresponding first power module 111 and the first terminal B of the third insulated gate bipolar transistor in the second power module 121. The test circuit 100 also includes a first capacitor C1 and a second capacitor C2. The first capacitor C1 is connected in parallel with the first power module group 110, and the second capacitor C2 is connected in parallel with the second power module group 120. In addition, the test circuit 100 also includes a resistor R1 connected in parallel with the first power module group 110 and an energy storage element R2 connected in parallel with the second power module group 120.

[0171] When testing the power modules, the control switch element 130 connects or disconnects the power connection point A in the first power module 111 to isolate or non-isolate the first power module group 110 from the second power module group 120. The first power modules 111 in the first power module group 110 are controlled to perform AC / DC conversion, achieving an inverter function. The switching frequency of the first and second insulated gate bipolar transistors is set to a first switching frequency and turned on or off at the first switching frequency, thereby converting the DC power output by the power supply 10 into AC power. The first power modules 111 in the first power module group 110 are tested, and the effective current value flowing through each first power module 111 is adjusted. When the effective current value reaches a preset first current value I1, the first power module 111 can be tested for a first duration. If the performance indicators of the first power module 111 meet the requirements when the effective current value reaches the first current value I1, the effective current value can be further increased. When the effective current value reaches a preset second current value I2, the first power module 111 can be tested for a second duration. If the performance indicators of the first power module 111 meet the use requirements when the current effective value reaches the second current value I2, the current effective value can be further increased. When the current effective value reaches the preset third current value I3, the first power module 111 can be tested within a third time period.

[0172] After completing the test of the first insulated gate bipolar transistor and the second insulated gate bipolar transistor at the first switching frequency, the switching frequency of the IGBT can be changed, the switching frequency of the first insulated gate bipolar transistor and the second insulated gate bipolar transistor can be set to the second switching frequency, and the above test steps can be repeated to test the various performance indicators of the first power module 111 at the second switching frequency.

[0173] When the second power module group 120 is not isolated from the first power module group 110, the second power modules 121 are also tested. The second power modules 121 in the second power module group 120 are controlled to perform AC / DC conversion to achieve rectification. The switching frequency of the third and fourth insulated gate bipolar transistors is set to a third switching frequency and turned on and off at the third switching frequency to convert the AC power converted by the first power module group 110 into DC power. The second power modules 121 in the second power module group 120 are tested by adjusting the effective current value (RMS) flowing through each second power module 121. When the effective current value reaches a predetermined fourth current value (I4), the second power modules 121 can be tested for a fourth duration. If the performance indicators of the second power modules 121 meet the requirements after the effective current value reaches the fourth current value (I4), the effective current value can be further increased. When the effective current value reaches a predetermined fifth current value (I5), the second power modules 121 can be tested for a fifth duration. If the performance indicators of the second power module 121 meet the use requirements when the effective current value reaches the fifth current value I5, the effective current value can be further increased. When the effective current value reaches the preset sixth current value I6, the second power module 121 can be tested within the sixth time period.

[0174] After completing the test of the switching frequency of the third insulated gate bipolar transistor and the fourth insulated gate bipolar transistor at the third switching frequency, the switching frequency of the IGBT can be changed, and the switching frequency of the third insulated gate bipolar transistor and the fourth insulated gate bipolar transistor can be set to the fourth switching frequency. The above test steps are repeated to test the various performance indicators of the power module at the fourth switching frequency.

[0175] During the test, the energy storage element R2 may be controlled to store the DC power converted by the second power module group 121 120 .

[0176] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A power module test circuit, characterized in that: include: a first power module group connected to a power source, comprising a plurality of first power modules, wherein the plurality of first power modules are configured to be connected in parallel with each other, each of the plurality of first power modules comprising a power connection point and a first insulated gate bipolar transistor and a second insulated gate bipolar transistor connected in series, wherein the power connection point is configured to be located between the first insulated gate bipolar transistor and the second insulated gate bipolar transistor; a second power module group, comprising a plurality of second power modules, wherein the plurality of second power modules are configured to be connected in parallel with each other, wherein the plurality of second power modules correspond one-to-one to the plurality of first power modules, and each of the plurality of second power modules is respectively connected to a corresponding first power module; A switching element is connected between the first power module group and the second power module group, and is configured to selectively isolate the second power module group from the first power module group so that the electric energy output by the first power module group is selectively transmitted to the second power module group. The switching element is configured to selectively connect the power connection points of the multiple first power modules to each other.

2. The test circuit according to claim 1, wherein: The test circuit further includes: A plurality of inductance elements correspond one-to-one to the plurality of second power modules, and each of the plurality of inductance elements is connected between a corresponding second power module and a first power module corresponding to the second power module.

3. The test circuit according to claim 2, wherein: Each of the plurality of second power modules includes a third insulated gate bipolar transistor and a fourth insulated gate bipolar transistor connected in series, each of the plurality of inductance elements is configured to be connected between a first end of the third insulated gate bipolar transistor in the corresponding second power module and the power connection point in the first power module corresponding to the second power module, and the first end of the third insulated gate bipolar transistor is connected to the fourth insulated gate bipolar transistor.

4. The test circuit according to any one of claims 1 to 3, characterized in that: The test circuit further includes: a first capacitor element connected in parallel with the first power module group, wherein the capacitance of the first capacitor element is determined according to a preset test voltage; A second capacitor element is connected in parallel with the second power module group, and a capacitance of the second capacitor element is determined according to the test voltage.

5. The test circuit according to any one of claims 1 to 3, characterized in that: The test circuit further includes: A resistance element is connected in parallel with the first power module group, and the resistance element is used to suppress the oscillation signal in the test circuit.

6. The test circuit according to any one of claims 1 to 3, characterized in that: The test circuit further includes: An energy storage element is connected in parallel with the second power module group, and the energy storage element is used to store the electric energy transmitted by the second power module group.

7. A power module testing method, used for the power module testing circuit according to claim 1, characterized in that: include: controlling the switch element to isolate or not isolate the second power module group from the first power module group; controlling the first power module group to convert the direct current output by the power supply into alternating current; testing the plurality of first power modules in the first power module group; In response to the second power module group being not isolated from the first power module group: controlling the second power module group to convert the alternating current converted by the first power module group into direct current; The plurality of second power modules in the second power module group are tested.

8. The testing method according to claim 7, characterized in that: Each of the plurality of first power modules includes a power connection point, and controlling the switch element to isolate or not isolate the second power module group from the first power module group includes: controlling the switch element to connect the power connection points in the plurality of first power modules to each other, so that the second power module group is isolated from the first power module group; or The switching element is controlled to disconnect the power connection points in the plurality of first power modules from each other, so that the second power module group is not isolated from the first power module group.

9. The testing method according to claim 7 or 8, characterized in that: The testing of the plurality of first power modules in the first power module group includes: adjusting an effective value of a current flowing through any one of the plurality of first power modules; In response to an effective value of a current flowing through any one of the plurality of first power modules reaching a first current value, testing the plurality of first power modules within a first time period; In response to an effective value of a current flowing through any one of the plurality of first power modules reaching a second current value, testing the plurality of first power modules within a second time period; In response to the effective value of the current flowing through any one of the plurality of first power modules reaching a third current value, the plurality of first power modules are tested within a third time period.

10. The testing method according to claim 7 or 8, characterized in that: The testing of the plurality of second power modules in the second power module group includes: adjusting an effective value of a current flowing through any second power module among the plurality of second power modules; In response to an effective value of a current flowing through any one of the plurality of second power modules reaching a fourth current value, testing the plurality of second power modules within a fourth time period; In response to an effective value of a current flowing through any one of the plurality of second power modules reaching a fifth current value, testing the plurality of second power modules within a fifth time period; In response to the effective value of the current flowing through any one of the plurality of second power modules reaching a sixth current value, the plurality of second power modules are tested within a sixth time period.

11. The testing method according to claim 7 or 8, characterized in that: Each of the plurality of first power modules includes a first insulated gate bipolar transistor and a second insulated gate bipolar transistor connected in series, and controlling the first power module group to convert the direct current output by the power supply into alternating current includes: Setting the switching frequency of the first insulated gate bipolar transistor and the second insulated gate bipolar transistor to a first switching frequency; The first insulated gate bipolar transistor and the second insulated gate bipolar transistor are controlled to be turned on or off at the first switching frequency to convert the direct current output by the power supply into alternating current.

12. The testing method according to claim 11, characterized in that: The test method further comprises: After testing the plurality of first power modules in the first power module group: Setting the switching frequency of the first insulated gate bipolar transistor and the second insulated gate bipolar transistor to a second switching frequency; The first insulated gate bipolar transistor and the second insulated gate bipolar transistor are controlled to be turned on or off at the second switching frequency to convert the direct current output by the power supply into alternating current.

13. The testing method according to claim 7 or 8, characterized in that: Each of the plurality of second power modules includes a third insulated gate bipolar transistor and a fourth insulated gate bipolar transistor connected in series, and controlling the second power module group to convert the AC power converted by the first power module group into DC power includes: Setting the switching frequency of the third insulated gate bipolar transistor and the fourth insulated gate bipolar transistor to a third switching frequency; The third insulated gate bipolar transistor and the fourth insulated gate bipolar transistor are controlled to be turned on or off at the third switching frequency to convert the alternating current converted by the first power module group into direct current.

14. The testing method according to claim 13, characterized in that: The test method further comprises: After testing the plurality of second power modules in the second power module group: Setting the switching frequency of the third insulated gate bipolar transistor and the fourth insulated gate bipolar transistor to a fourth switching frequency; The third insulated gate bipolar transistor and the fourth insulated gate bipolar transistor are controlled to be turned on or off at the fourth switching frequency to convert the alternating current converted by the first power module group into direct current.

15. The testing method according to claim 7 or 8, characterized in that: The test circuit further includes an energy storage element connected in parallel with the second power module group, and the test method further includes: The energy storage element is controlled to store the direct current converted by the second power module group.

Images