Test device

Abstract

The application discloses a test device, and relates to the technical field of converter testing, which comprises a connection interface, a test circuit module, a switching circuit module and a control circuit module, wherein the connection interface is used for connecting a to-be-tested converter; the test circuit module comprises a plurality of function test branches, each of which is used for outputting a corresponding test signal to the connected to-be-tested converter through the connection interface and receiving a corresponding test feedback signal output by the to-be-tested converter in response to the test signal; the switching circuit module is connected with each function test branch through a plurality of output ends; the control circuit module is connected with the input end of the switching circuit module, and the control circuit module controls the switching circuit module to be in communication with the corresponding function test branch, so that the corresponding function test branch works and outputs a test result according to the received test feedback signal. Through the plurality of function test branches, comprehensive testing of a plurality of different functions of the to-be-tested converter is realized.

Description

Technical Field

[0001] This application relates to the field of converter testing technology, and in particular to a testing device. Background Technology

[0002] Functional testing of converters is crucial for controlling product quality. As products evolve, the number of functions requiring testing increases. Existing testing methods are unable to perform tests on multiple different functions of the converter under test, leading to frequent product quality issues. Utility Model Content

[0003] The main objective of this application is to provide a testing device that addresses the technical problem of being unable to test multiple different functions of a converter under test.

[0004] To achieve the above objectives, this application proposes a testing apparatus comprising:

[0005] A connection interface, which is used to connect the converter under test;

[0006] The test circuit module includes multiple functional test branches. Each functional test branch is used to output a corresponding test signal to the connected converter under test through the connection interface, and to receive a corresponding test feedback signal output by the converter under test in response to the test signal.

[0007] A switching circuit module, wherein multiple output terminals of the switching circuit module are connected to each of the functional test branches;

[0008] A control circuit module is connected to the input terminal of the switching circuit module. The control circuit module controls the switching circuit module to connect with the corresponding functional test branch so that the corresponding functional test branch works and outputs test results according to the received test feedback signal.

[0009] In one embodiment, the plurality of functional test branches include at least one of the following: AC power supply test branch, communication test branch, parameter setting test branch, daisy-chain test branch, software version reading test branch, temperature test branch, insulation resistance test branch, open-loop test branch, short-circuit loop test branch, virtual synchronous generator test branch, overvoltage test branch, and polarity reverse connection test branch.

[0010] In one embodiment, the connection interface includes an AC power port, and one of the plurality of functional test branches includes an AC power supply test branch. The AC power supply test branch includes a transformer, the first end of which is used to connect to an AC power source; the second end of the transformer is provided with a plurality of secondary windings, which are connected to the AC power port. Each secondary winding is used to output a test AC current of a corresponding voltage level to the AC side of the converter under test, so that the converter under test outputs a corresponding AC power supply test feedback signal according to the received test AC current.

[0011] In one embodiment, the first end of the transformer has a primary winding, and the switching circuit module includes an overcurrent protection circuit, through which the primary winding is connected to an AC power source.

[0012] In one embodiment, the connection interface includes an AC power port, and the plurality of functional test branches also include a short-circuit loop test branch;

[0013] The AC power port includes three phase interfaces, and the short-circuit loop test branch is connected between the three phase interfaces. The short-circuit loop test branch is used to output a short-circuit test signal to the converter under test, so that the converter under test outputs a short-circuit test feedback signal according to the short-circuit test signal. The control circuit module is used to output a first alarm signal according to the short-circuit test feedback signal.

[0014] In one embodiment, the connection interface includes a DC power port, and among the plurality of functional test branches is an overvoltage test branch. The overvoltage test branch includes a bidirectional DC source, the input of which is connected to an AC power source, and the output of which is connected to the DC power port. The bidirectional DC source is used to convert the AC power from the AC power source into test DC power and output it to the DC side of the converter under test through the DC power port, so that the converter under test outputs a corresponding overvoltage test feedback signal according to the received test DC power.

[0015] In one embodiment, the connection interface includes a DC power port, and the plurality of functional test branches include a polarity reverse test branch, which includes a bidirectional DC source. The switching circuit module includes a forward selection branch and a reverse selection branch. The input terminals of the forward selection branch and the reverse selection branch are respectively connected to the output terminal of the bidirectional DC source, and the output terminals of the forward selection branch and the reverse selection branch are respectively connected to the DC power port.

[0016] When the forward selection branch is closed and the reverse selection branch is open, a positive test voltage is output to the converter under test through the bidirectional DC source;

[0017] When the forward selection branch is open and the reverse selection branch is closed, a reverse test voltage is output to the converter under test through the bidirectional DC source.

[0018] In one embodiment, the DC power supply port includes a first positive terminal, a first negative terminal, a second positive terminal, and a second negative terminal;

[0019] Wherein, the first positive terminal and the first negative terminal form a first DC power supply circuit, and the second positive terminal and the second negative terminal form a second DC power supply circuit;

[0020] The polarity reverse connection test branch includes a first output terminal block and a second output terminal block. The first output terminal block is connected to the first positive terminal and the second positive terminal; the second output terminal block is connected to the first negative terminal and the second negative terminal.

[0021] The forward selection branch includes a first relay and a second relay, and the reverse selection branch includes a third relay and a fourth relay. The positive terminal of the bidirectional DC source is connected to the first terminal of the first relay and the first terminal of the third relay, respectively. The negative terminal of the bidirectional DC source is connected to the first terminal of the second relay and the first terminal of the fourth relay, respectively. The second terminals of the first relay and the second relay are connected to the first output terminal block, respectively. The second terminals of the third relay and the fourth relay are connected to the second output terminal block, respectively.

[0022] In one embodiment, the test circuit module further includes an isolation circuit, the output terminal of which is connected to the input terminal of the bidirectional DC source and the input terminal of the transformer, respectively, and the input terminal of the isolation circuit is used to connect to an AC power source.

[0023] In one embodiment, the test circuit module further includes a test load, which is used to discharge electrical energy from the converter under test.

[0024] The control circuit module is specifically used to control the test load to work after receiving the test completion signal.

[0025] In one embodiment, the plurality of functional test branches include a communication test branch, and there are multiple connection interfaces, including at least one of a network communication interface, a CAN communication interface, a daisy-chain communication interface, and an RS485 communication interface.

[0026] The communication test branch is connected to the connection interface. The communication test branch is used to output the corresponding communication test signal when the converter under test is connected to each of the connection interfaces, and to receive the corresponding test feedback signal output by the converter under test in response to the test signal. The control circuit module is specifically used to output the test result according to the received communication test feedback signal.

[0027] In one embodiment, the plurality of functional test branches include a daisy-chain test branch, the connection interface includes a daisy-chain communication interface, the daisy-chain test branch is used to connect to the connected converter under test to form a ring circuit through the daisy-chain communication interface, and the control circuit module is specifically used to receive the onboard temperature signal of the product under test through the ring circuit.

[0028] In one embodiment, the plurality of functional test branches include an insulation impedance test branch, the insulation impedance test branch includes a resistor plate, the connection interface includes a DC power port, a first connection terminal of the resistor plate is used to connect to the positive terminal of the converter under test through the positive terminal of the DC power port, a second connection terminal of the resistor plate is used to connect to the negative terminal of the converter under test through the negative terminal of the DC power port, and a third connection terminal of the resistor plate is used to connect to the ground terminal of the converter under test.

[0029] The resistor board is used to output a DC high voltage test signal to the converter under test, so that the converter under test outputs a corresponding insulation impedance signal according to the DC high voltage test signal. The control circuit module is used to output a second alarm signal according to the insulation impedance signal.

[0030] In one embodiment, the resistor plate comprises two aluminum-cased resistors connected in series.

[0031] In one embodiment, the plurality of functional test branches include a temperature test branch, which is used to detect the test environment temperature, and the control circuit module is used to output test results based on the test environment temperature and the temperature feedback signal transmitted by the converter under test.

[0032] In one embodiment, the testing apparatus further includes a cooling fan for operation when the testing apparatus is connected to an AC power source.

[0033] The technical solution of this application enables the testing device to comprehensively test multiple different functions of the converter under test by setting up multiple functional test branches. The control circuit module connects to the corresponding functional test branches through the control switching circuit module, enabling the corresponding functional test branches to operate. The coordinated operation of the connection interface, test circuit module, switching circuit module, and control circuit module realizes automated testing of different functions of the converter under test. The control circuit module determines whether each function of the converter under test is normal based on the received test feedback signals and automatically outputs the test results, thereby realizing comprehensive testing of the hardware and software of the converter under test. By setting up and improving the functional test branches according to the functional testing requirements of the converter under test, the problem of not being able to comprehensively test multiple different functions is effectively solved, ensuring full coverage of product functional testing and improving product quality. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0035] Figure 1 A schematic diagram of a module provided for one embodiment of the calibration device of this application;

[0036] Figure 2 One of the electrical schematic diagrams provided for an embodiment of the calibration device of this application;

[0037] Figure 3 A second electrical schematic diagram provided for an embodiment of the calibration device of this application;

[0038] Figure 4 Electrical schematic diagram three provided for an embodiment of the calibration device of this application;

[0039] Figure 5 Electrical schematic diagram four provided for an embodiment of the calibration device of this application;

[0040] Figure 6 Fifth electrical schematic diagram provided for an embodiment of the calibration device of this application;

[0041] Figure 7 Electrical schematic diagram six provided for an embodiment of the calibration device of this application;

[0042] Figure 8 Seventh electrical schematic diagram provided for an embodiment of the calibration device of this application;

[0043] Figure 9Eighth electrical schematic diagram provided for an embodiment of the calibration device of this application;

[0044] Figure 10 Electrical schematic diagram nine, provided for an embodiment of the calibration device of this application;

[0045] Figure 11 Electrical schematic diagram ten provided for an embodiment of the calibration device of this application;

[0046] Figure 12 Electrical schematic diagram eleventh of an embodiment of the calibration device of this application;

[0047] Figure 13 Electrical schematic diagram XII, provided for an embodiment of the calibration device of this application;

[0048] Figures 14(a) to 14(d) A schematic diagram of a daisy-chain switching circuit provided for one embodiment of the calibration device of this application;

[0049] Figure 15 Electrical schematic diagram thirteenth provided for an embodiment of the calibration device of this application;

[0050] Figure 16 A schematic diagram of the panel and connection interface provided for one embodiment of the calibration device of this application;

[0051] Figure 17 This is a schematic diagram of a structure provided for one embodiment of the calibration device of this application.

[0052] Explanation of icon numbers:

[0053] 100. Tooling housing; 110. Connection interface; 121. First terminal block; 122. Second terminal block; 123. Third terminal block;

[0054] 200. Test circuit module; 201. Functional test branch; 210. Transformer; 220. Bidirectional DC power supply; 230. Resistor board;

[0055] 300. Switching circuit module;

[0056] 400. Control circuit module;

[0057] 500. The converter under test.

[0058] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0059] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0060] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0061] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0062] Functional testing of converters is crucial for controlling product quality. However, with continuous product evolution, ensuring comprehensive functional testing remains a critical challenge. Existing testing technologies cannot perform multi-functional testing on the converter under test, let alone achieve complete functional testing, leading to frequent product quality issues.

[0063] Reference Figure 1 In order to enable the testing of multiple different functions of the converter under test, and further to achieve comprehensive testing of multiple different functions of the converter under test, this application proposes a testing device.

[0064] The testing device includes a connection interface 110, a test circuit module 200, a switching circuit module 300, and a control circuit module 400. The connection interface 110 is used to connect to the converter under test (DUT) 500. The connection interface can be located on a fixture housing 100, which primarily serves to support and protect the internal circuitry and other components of the testing device. The fixture housing 100 has the connection interface 110 for connecting to the DUT 500, providing a connection basis for testing and ensuring smooth testing. The connection interface 110 can be designed as a socket, plug, terminal block, or other type of connector for electrical and communication connections with the DUT 500. The fixture housing 100 may also include auxiliary components such as heat dissipation holes, indicator lights, and operation buttons, as well as user interface devices such as a touch screen and LCD display; the specific configuration can be determined according to actual needs.

[0065] Reference Figure 2 , Figure 3 The test circuit module 200 includes multiple functional test branches 201. Each functional test branch 201 is used to output a corresponding test signal to the connected converter under test 500 through the connection interface 110, and to receive the corresponding test feedback signal output by the converter under test 500 in response to the test signal.

[0066] Understandably, each functional test branch 201 is responsible for outputting specific test signals (such as electrical signals like voltage, current, and frequency, or other test signals) to the converter under test 500, and receiving test feedback signals from the converter under test 500. These test signals are used to simulate various conditions in the actual working environment to evaluate the performance and quality of the converter. Through the setup of the test circuit module 200, various functions of the converter can be tested, such as AC power supply testing, electrical performance testing, and insulation resistance testing.

[0067] like Figure 4 As shown, multiple output terminals of the switching circuit module 300 are connected to each functional test branch 201; the control circuit module 400 is connected to the input terminal of the switching circuit module 300, and the control circuit module 400 controls the switching circuit module 300 to connect with the corresponding functional test branch 201 so that the corresponding functional test branch 201 works, and outputs the test result according to the received test feedback signal.

[0068] Under the control of the control circuit module 400, the switching circuit module 300 is responsible for selectively connecting different functional test branches 201. In this way, the testing device can select the appropriate test branch for testing according to different testing requirements. The switching circuit module 300 can be implemented using devices such as relays, analog switches, and digital switches, or circuits containing these devices.

[0069] The control circuit module 400 is also connected to the test circuit module 200. The control circuit module 400 receives and processes the test feedback signals output by the test circuit module 200. It analyzes and processes the test feedback signals according to preset test procedures and judgment criteria, and finally outputs the test results. The control circuit module 400 can be implemented using a microcontroller (such as a single-chip microcomputer), a programmable logic controller (PLC), a digital signal processor (DSP), a field-programmable gate array (FPGA), or other controllers or circuits containing these controllers. It controls the operation of the entire testing device to automate the testing process and improve accuracy.

[0070] The embodiments of this application, by setting up multiple functional test branches 201, enable the testing device to comprehensively test multiple different functions of the converter under test 500. The control circuit module 400 connects to the corresponding functional test branch 201 through the control switching circuit module 300, enabling the corresponding functional test branch 201 to operate. The coordinated operation of the connection interface 110, the test circuit module 200, the switching circuit module 300, and the control circuit module 400 achieves automated testing of different functions of the converter under test 500. Based on the received test feedback signals, the control circuit module 400 determines whether each function of the converter under test 500 is normal and automatically outputs the test results, thereby achieving comprehensive testing of the hardware and software of the converter under test 500. By setting and improving the functional test branches 201 according to the functional testing requirements of the converter under test 500, the problem of not being able to comprehensively test multiple different functions is effectively solved, ensuring full coverage of product functional testing and improving product quality.

[0071] Reference Figure 3 , Figure 4 In one embodiment, the plurality of functional test branches 201 include at least one of the following: AC power supply test branch, communication test branch, parameter setting test branch, daisy chain test branch, software version reading test branch, temperature test branch, insulation impedance test branch, open loop test branch, short circuit loop test branch, virtual synchronous generator test branch, overvoltage test branch, and polarity reverse connection test branch.

[0072] By configuring multiple functional test branches 201, the AC power supply test, communication test, parameter setting test, daisy-chain test, software version reading test, temperature test, insulation impedance test, open-loop test, short-circuit loop test, VSG (Virtual Synchronous Generator) test, overvoltage test, and polarity reverse connection test can be performed on the converter 500 under test. Among them, the parameter setting test includes, but is not limited to, CMU (Communication Management Unit) parameter setting, CMU address bit setting, and time setting. Specifically, at least some or all of the multiple functional test branches 201 can be configured according to actual needs, and different functional tests can be switched by controlling the connection or disconnection of the corresponding functional test branches 201 according to actual test requirements.

[0073] The AC power supply test branch provides test power to the converter under test (DUT) 500, simulating different voltage, frequency, and load conditions in a real power grid environment to test the performance and stability of the DUT 500. The communication test branch tests the communication capabilities of the DUT 500, including communication protocol compatibility, data transmission accuracy, and stability. The parameter setting test branch allows for the configuration and adjustment of the converter's parameters, verifying its ability to correctly receive and apply external parameter settings, such as CMU parameters, address bits, and time, ensuring the flexibility and configurability of its operating state. The daisy-chain test branch tests the communication function of the DUT 500 in a daisy-chain connection, improving the stability and accuracy of signal transmission in multi-device connection scenarios. The software version reading test branch reads the software version information of the DUT 500, confirming that the running software version is compatible with the requirements or the current system and application. The temperature test branch detects temperature changes during the operation of the DUT 500, ensuring it operates within a safe temperature range and preventing overheating to some extent. The insulation impedance test branch is used to detect the insulation impedance of the converter, ensuring its electrical insulation performance meets safety standards and preventing electrical leakage and short circuits to a certain extent. The open-loop test branch is used to test the output response of the converter under test (DUT) 500 under open-loop conditions, evaluating its performance without feedback control. The short-circuit loop test branch simulates short-circuit conditions, testing the protection functions and response capabilities of the DUT 500 during short circuits. The virtual synchronous generator (VSG) test branch simulates the operating characteristics of a synchronous generator (VSG), testing the performance of the DUT 500 in grid-connected or similar application scenarios. The overvoltage test branch simulates overvoltage conditions, testing the protection capabilities and stability of the DUT 500. The reverse polarity test branch simulates reverse polarity faults, testing the converter's protection functions and response capabilities.

[0074] Reference Figure 4The testing device includes multiple switching circuits, including the aforementioned switching circuit module 300. A control circuit module 400 is connected to the multiple switching circuits and is used to control the switching circuits to activate and execute corresponding test functions, or to control the switching circuits to deactivate and stop executing corresponding test functions. In addition to the aforementioned AC power supply tests, communication tests, and parameter setting tests, some of the multiple switching circuits are also used to implement emergency stop control (e.g., ...). Figure 4 The DI shown); some switching circuits are also used as reserved circuits (such as DI); Figure 4 The D0 shown can be used to implement other testing functions; the specific settings can be adjusted according to actual needs, and are not limited here.

[0075] Optionally, the connection interface 110 includes at least one or more of the following: a connection port and a communication interface. The connection port includes, but is not limited to, an AC power port and a DC power port; the communication interface includes, but is not limited to, a network communication interface, a CAN communication interface, a daisy-chain communication interface, and an RS485 communication interface; specific configurations can be made according to actual needs and are not limited here.

[0076] Reference Figure 2 In one embodiment, the connection interface 110 includes an AC power port, and the multiple functional test branches 201 include an AC power supply test branch. The AC power supply test branch includes a transformer 210. The first end of the transformer 210 is used to connect to the AC power source. The second end of the transformer 210 is provided with multiple secondary windings, which are connected to the AC power port. Each secondary winding is used to output a test AC current of the corresponding voltage level to the AC side of the converter under test 500, so that the converter under test 500 outputs a corresponding AC power supply test feedback signal according to the received test AC current.

[0077] Specifically, secondary windings can be configured to accommodate different rated voltages. By setting multiple secondary windings with different rated voltages on the transformer 210, these secondary windings are independent and can be adapted to multiple different models of the converter under test 500, expanding the applicability of product testing and improving the versatility of the testing device. In addition to being used for AC power supply testing, it can also be used to further realize open-loop testing, completing open-loop testing without receiving corresponding feedback signals, and realizing open-loop testing at different voltage levels.

[0078] As is understandable, open-loop operation refers to the operation of a motor or control system without feedback regulation, operating solely based on the input control signal without relying on feedback signals to correct its state. The testing device in this application possesses open-loop testing capabilities at different voltage levels. Open-loop testing at different voltage levels refers to testing and verifying the open-loop operating state of a power electronic system or equipment under different voltage levels (such as low, medium, and high voltage). This type of testing is used to evaluate the stability and performance of the system under different voltage conditions, improving its reliability in various operating scenarios.

[0079] Reference Figure 2 In one embodiment, the control circuit module 400 is specifically used to control the operation of the corresponding secondary winding after receiving the parameters of the product under test, and the voltage level includes at least one of 400V, 480V, 690V and 800V.

[0080] The second end of the transformer 210 is provided with multiple secondary windings, which specifically include a primary winding providing a rated voltage of 400V, a secondary winding providing a rated voltage of 480V, a tertiary winding providing a rated voltage of 690V, and a quaternary winding providing a rated voltage of 800V.

[0081] Optionally, the parameters of the product under test can be, but are not limited to, those obtained by scanning a QR code, those obtained by receiving a user input signal, those obtained by receiving a communication signal when the converter under test 500 is connected through the connection interface 110, or those obtained by the product parameters preset by the test pipeline; the specific parameters can be set according to actual conditions and are not limited here.

[0082] Optionally, the second end of transformer 210 is also equipped with a switching circuit, through which multiple secondary windings are connected to the AC side of the converter under test 500. Specifically, the primary, secondary, tertiary, and quaternary windings are connected to the converter under test 500 via relays KM4, KM5, KM6, and KM7 or other switching circuits. When the test device has an AC power port, the multiple secondary windings can be connected to the AC power port of the test device via the switching circuit, and then connected to the AC side of the converter under test 500 via the AC power port.

[0083] Furthermore, fuses can be added to the switching circuit. Specifically, the primary, secondary, tertiary, and quaternary windings of the second terminal of transformer 210 are connected to the first terminal of relay KM8 via relays KM4, KM5, KM6, and KM7, respectively. The second terminal of relay KM8 is connected in series with circuit breaker Q5 and the fuse, and then connected to the AC power port. The AC power port includes a first AC port, a second AC port, and a third AC port, corresponding to the R, S, and T interfaces of the three phase interfaces, respectively. The fuse provides circuit protection by automatically disconnecting the circuit in the event of overload or other phenomena, protecting equipment and lines, and providing safety assurance for the circuit.

[0084] Reference Figure 5 In some embodiments, in order to detect the current of the converter under test 500, current transformers CT1, CT2 and CT3 for detecting the current of the three phases A, B, and C can be installed at the intermediate connection point of the circuit breaker Q5 and the fuse respectively; the data detected by the current transformers are transmitted to the energy meter.

[0085] By setting multiple secondary windings with different rated voltages on transformer 210, multiple different models of converters under test (DUTs) 500 can be adapted; furthermore, it can help the testing device detect whether the various hardware and software of the DUTs 500 are working properly. In addition, open-loop testing can be completed without feedback, realizing open-loop testing at different voltage levels. In the embodiments of this application, it can be used to implement 300V, 1400V open-loop testing, or other voltage levels, without limitation.

[0086] Reference Figure 2 In one embodiment, the first end of the transformer 210 has a primary winding, and the switching circuit module 300 includes an overcurrent protection circuit, through which the primary winding is connected to an AC power supply.

[0087] In some specific embodiments, the overcurrent protection circuit includes relay KM2, a load resistor, circuit breaker Q4, and relay KM3. The primary winding of the transformer 210 has ABC ports. The primary winding is connected to the output of the AC power supply through circuit breaker Q4. Relay KM3 is connected in series between the ABC ports of the primary winding and circuit breaker Q4. The two ends of relay KM3 are connected in parallel with the series circuit consisting of relay KM2 and the load resistor. Relay KM3 can control the opening and closing of the circuit between the ABC ports of the primary winding of transformer 210 and circuit breaker Q4. When relay KM3 is closed, the circuit is open, the load resistor is connected to the circuit, and the load resistor can limit the current of the primary winding of transformer 210, thus providing current limiting protection. At this time, transformer 210 can work normally, receiving and converting electrical energy. When relay KM3 is open, the circuit is closed, transformer 210 stops working, thereby cutting off the power transmission. Specifically, when a fault occurs in the primary winding of transformer 210 or circuit breaker Q4 (such as overload, short circuit, etc.), relay KM3 can quickly disconnect the circuit, which can prevent the fault from spreading to a certain extent and protect the safety of subsequent circuits and equipment. This protection mechanism helps to reduce safety hazards such as equipment damage and fire caused by faults.

[0088] In some optional embodiments, the AC power supply is used to provide 400V or other AC power to the test equipment. A circuit breaker Q2 is provided at the output of the AC power supply; specifically, the first terminal of circuit breaker Q2 can be connected to the output of the AC power supply. The primary winding of transformer 210 is connected to the second terminal of circuit breaker Q2 via circuit breaker Q4, and is also connected to the AC power supply via circuit breaker Q2.

[0089] Reference Figure 2 In one embodiment, the connection interface 110 includes an AC power port, and the multiple functional test branches 201 also include a short-circuit loop test branch.

[0090] The AC power port includes three phase interfaces, and a short-circuit loop test branch is connected between the three phase interfaces. The short-circuit loop test branch is used to output a short-circuit test signal to the converter under test 500, so that the converter under test 500 outputs a short-circuit test feedback signal according to the short-circuit test signal. The control circuit module 400 is used to output a first alarm signal according to the short-circuit test feedback signal.

[0091] The AC power port serves as the connection interface 110 between the test device and the converter under test 500, used to output short-circuit test signals and receive short-circuit test feedback signals. Optionally, the AC power port includes a first AC port, a second AC port, and a third AC port, corresponding to interface R, interface S, and interface T of the three phase interfaces, respectively. In the embodiments of this application, a short-circuit loop test branch is connected between the three phase interfaces. The short-circuit loop test branch is set between the three phase interfaces to implement short-circuit loop testing and verify the protection function and response speed of the converter under test 500 under short-circuit conditions.

[0092] The short-circuit loop test branch is used to simulate short-circuit conditions and test the protection function and response capability of the converter under test 500 during a short circuit. The control circuit module 400 is used to determine whether the protection function and response capability (such as response time) of the converter under test 500 during a short circuit are qualified based on the received short-circuit test feedback signal. Specifically, it is used to output a first alarm signal when the protection function and response capability of the converter under test 500 during a short circuit are unqualified (and to display the alarm through corresponding indicator lights, display screens, buzzers, etc.). In addition, the control circuit module 400 is also used to output a short-circuit loop test qualified signal when the protection function and response capability of the converter under test 500 during a short circuit are qualified. The specific settings can be adjusted according to actual conditions and are not limited here.

[0093] Reference Figure 2 In one embodiment, the connection interface 110 includes a DC power port, and the multiple functional test branches 201 include a virtual synchronous generator test branch (VSG test branch). The virtual synchronous generator test branch includes a bidirectional DC source 220. The input terminal of the bidirectional DC source 220 is used to connect to an AC power source, and the output terminal is connected to the DC power port. It is used to convert the AC power from the AC power source into test DC power and output it to the DC side of the converter under test 500 through the DC power port, so as to realize the grid connection test of the converter under test 500 and realize the grid connection control of the converter under test 500 through a preset VSG strategy.

[0094] By setting up a bidirectional DC source 220 to convert AC and DC power, grid connection testing of the converter 500 product under test is achieved. VSG technology is used to simulate the inertia and damping characteristics of a traditional synchronous generator, enabling the converter to better adapt to dynamic changes in the power grid during grid connection, thus improving grid connection stability and reliability.

[0095] Reference Figure 2In one embodiment, the connection interface 110 includes a DC power port, and the multiple functional test branches 201 include an overvoltage test branch. The overvoltage test branch includes a bidirectional DC source 220. The input terminal of the bidirectional DC source 220 is used to connect to an AC power source, and the output terminal is connected to the DC power port. It is used to convert the AC power from the AC power source into test DC power and output it to the DC side of the converter under test 500 through the DC power port, so that the converter under test 500 outputs a corresponding overvoltage test feedback signal according to the received test DC power.

[0096] In some optional embodiments, an AC power supply is used to provide 400V or other AC power to the test equipment. The output of the AC power supply is equipped with a circuit breaker Q2, specifically, the first terminal of circuit breaker Q2 can be connected to the output of the AC power supply. The first terminal of the bidirectional DC source 220 is connected in series with a circuit breaker Q3 to the second terminal of circuit breaker Q2 to access the AC power supply; the second terminal of the bidirectional DC source 220 is connected to the DC side of the converter under test 500 via a DC power interface.

[0097] The overvoltage test can be implemented through the overvoltage test branch, which provides a DC voltage source exceeding the rated voltage to the converter under test 500 and detects the current and voltage response of the converter under test 500. The control circuit module 400 verifies whether the overvoltage protection function and stability of the converter under test 500 are normal under overvoltage conditions based on the received overvoltage test feedback signal.

[0098] In addition, overvoltage conditions can be simulated through related circuits such as transformer 210 to provide an AC voltage source exceeding the rated voltage to the PCS; the specific settings can be adjusted according to actual conditions and are not limited here.

[0099] Reference Figure 2 In one embodiment, the connection interface 110 includes a DC power port, and the multiple functional test branches 201 include a polarity reversal test branch, which includes a bidirectional DC source 220. The switching circuit module 300 includes a forward selection branch and a reverse selection branch. The input terminals of the forward selection branch and the reverse selection branch are respectively connected to the output terminals of the bidirectional DC source 220, and the output terminals of the forward selection branch and the reverse selection branch are respectively connected to the DC power port.

[0100] When the forward selection branch is closed and the reverse selection branch is open, a positive test voltage is output to the converter under test 500 through the bidirectional DC source 220;

[0101] When the forward selection branch is open and the reverse selection branch is closed, a reverse test voltage is output to the converter under test 500 through the bidirectional DC source 220.

[0102] The control circuit module 400 controls the connection or disconnection of the forward and reverse selection branches, thereby determining the output direction of the bidirectional DC source 220: When the forward selection branch is closed and the reverse selection branch is open, the bidirectional DC source 220 outputs a forward test current to the converter under test 500 through the forward selection branch, which is used to detect the output accuracy of the converter under test 500 under forward current, improving the accuracy of the converter under test 500 in the forward current operating mode. When the reverse selection branch is closed and the forward selection branch is open, the bidirectional DC source 220 outputs a reverse test current to the converter under test 500 through the reverse selection branch, which is used to detect the output accuracy of the converter under test 500 under reverse current, ensuring the stability of the converter under test 500 in the reverse current operating mode. By configuring the forward and reverse selection branches in this way, the output direction of the bidirectional DC source 220 can be flexibly switched, enabling comprehensive testing of the converter under test 500, meeting the requirements for forward and reverse current detection, and improving the efficiency and accuracy of the testing. The polarity reverse connection test branch is also used to simulate a polarity reverse connection fault, testing the protection function and response capability of the converter under test 500 under polarity reverse connection conditions.

[0103] Reference Figure 2 In one embodiment, the DC power supply port includes a first positive terminal DC1+, a first negative terminal DC1-, a second positive terminal DC2+, and a second negative terminal DC2-; wherein the first positive terminal DC1+ and the first negative terminal DC1- constitute a first DC power supply circuit, and the second positive terminal DC2+ and the second negative terminal DC2- constitute a second DC power supply circuit.

[0104] The polarity reverse connection test branch includes a first output terminal block S1 and a second output terminal block S2. The first output terminal block S1 is connected to the first positive terminal DC1+ and the second positive terminal DC2+; the second output terminal block S1 is connected to the first negative terminal DC1- and the second negative terminal DC2-.

[0105] The forward selection branch includes a first relay KZ1 and a second relay KZ2, and the reverse selection branch includes a third relay KZ3 and a fourth relay KZ4. The positive terminal of the bidirectional DC source 220 is connected to the first terminal of the first relay KZ1 and the first terminal of the third relay KZ3, respectively. The negative terminal of the bidirectional DC source 220 is connected to the first terminal of the second relay KZ2 and the first terminal of the fourth relay KZ4, respectively. The second terminals of the first relay KZ1 and the second terminals of the second relay KZ2 are connected to the first output terminal block S1, respectively. The second terminals of the third relay KZ3 and the second terminals of the fourth relay KZ4 are connected to the second output terminal block S2, respectively.

[0106] The DC power port serves as the connection interface 110 between the test device and the converter under test 500, used for transmitting test signals and test power. The DC power port flexibly switches the output direction of the bidirectional DC source 220 through two independent DC power circuits and corresponding relays or other switching components, enabling reverse polarity testing. It also meets the testing requirements of the converter under test 500 in different operating modes by outputting different forward and reverse test currents.

[0107] Optionally, the first output terminal block S1 is connected to the first positive terminal DC1+ via relay KZ5 and to the second positive terminal DC2+ via relay KZ7; the second output terminal block S2 is connected to the first negative terminal DC1- via relay KZ6 and to the second negative terminal DC2- via relay KZ8.

[0108] Specifically, the switching circuit module 300 controls the on / off states of different relays (KZ5, KZ6, KZ7, KZ8) to switch the connection between the bidirectional DC source 220 and the DC power supply ports (DC1+, DC1-, DC2+, DC2-). The polarity reverse connection test is performed on the product under test, and the contactors are all controlled by the host computer to achieve automated testing. When a forward test current is required, relays KZ1 and KZ2 are closed, and relays KZ3 and KZ4 are open. The bidirectional DC source 220 outputs a forward test current to the converter under test 500 through the forward path formed by the closed relays KZ1 and KZ2. When a reverse test current is required, relays KZ3 and KZ4 are closed, and relays KZ1 and KZ2 are open. The bidirectional DC source 220 outputs a reverse test current to the converter under test 500 through the reverse path formed by the closed relays KZ3 and KZ4. The on / off state of each relay is precisely controlled by the control circuit module 400. The control circuit module 400 dynamically adjusts the on / off state of the relays based on the received test feedback signal and the parameter signal of the converter under test 500 detected by the detection circuit, so as to optimize the automation and accuracy of the test process.

[0109] Reference Figure 6 , Figure 7 In some embodiments, the test device is powered by a three-phase system, drawing 220V. The test device is equipped with a control switch, which is used to start the test by closing the switch or to stop the test by closing the switch.

[0110] Reference Figure 8 In one embodiment, the test circuit module 200 further includes an isolation circuit. The output terminal of the isolation circuit is connected to the input terminal of the bidirectional DC source 220 and the input terminal of the transformer 210, respectively. The input terminal of the isolation circuit is used to connect to an AC power source.

[0111] Optionally, the output terminal of the AC power supply is connected to the input terminals of the bidirectional DC power supply 220 and the transformer 210 respectively via circuit breaker Q2, and specifically, an isolation circuit can be connected between the output terminal of the AC power supply and circuit breaker Q2. The isolation circuit includes an isolation transformer T1, the input terminal of which is connected to the AC voltage source, and the output terminal of the isolation transformer T1 outputs AC power to power the transformer 210, the bidirectional DC power supply 220, the test platform, and other test devices, as well as the display screen. The display screen is mainly used to display information detected during the test, parameter information of the converter under test 500, test results, etc. Specifically, the testing device also includes a first terminal block 121, a second terminal block 122, and a third terminal block 123. The testing device is used to supply power to switching components such as circuit breakers or other associated circuits associated with the bidirectional DC source 220 through the first terminal block 121; to supply power to switching components such as circuit breakers or other associated circuits associated with the transformer 210 through the second terminal block 122; and to supply power to computers (host computers, mainframes) or other components of the testing device, as well as other output devices such as displays, through the third terminal block 123.

[0112] When the AC power supply outputs electrical energy to the isolation circuit, the isolation circuit isolates and converts the electrical energy through the isolation transformer T1, and then provides the required electrical energy to the bidirectional DC power supply 220, transformer 210, etc. By setting the isolation transformer T1 to isolate the AC power supply, during the test, when the converter under test 500 starts up or when the converter under test 500 fails, the isolation transformer 210 plays a protective role, preventing the surge voltage from damaging other electrical components to a certain extent.

[0113] Reference Figure 2 In one embodiment, the test circuit module 200 further includes a test load for discharging electrical energy from the converter 500 under test.

[0114] The control circuit module 400 is specifically used to control the test load to work after receiving the test completion signal.

[0115] During testing, the converter under test 500 may output excess electrical energy. This energy needs to be safely discharged through the test load to resolve the problem of equipment damage caused by energy accumulation. In this way, it can also be used to achieve accurate, efficient and safe testing of the converter under test 500.

[0116] In some optional embodiments of this application, the test load can specifically be an aluminum-cased resistor. Specifically, a contactor KZ11, an aluminum-cased resistor for discharging the converter under test 500, and a contactor KZ12 are connected in series between the first output terminal block S1 and the second output terminal block S2. After the test is completed, the product is discharged to the safety standard by closing contactors KZ11 and KZ12. In order to speed up the discharge time and improve the test efficiency, the test device adds a discharge aluminum-cased resistor to discharge the electrical energy of the converter under test 500, which can greatly reduce the discharge time and improve the discharge efficiency. In addition, the use of an aluminum-cased resistor also enhances the safety of the test process, so that the converter under test 500 will not be damaged due to energy accumulation during the discharge process.

[0117] Optionally, the test completion signal can be, but is not limited to, a signal triggered by the user, an output from the detection circuit of the test device, or an automatic output from the test circuit module 200. Furthermore, in some embodiments of this application, besides selecting to connect the corresponding functional test branch 201 according to actual needs to achieve various different test items, it is also possible to set corresponding test items and test sequences for different types and models of converters under test 500, so that when the converter under test 500 is connected, the test of the converter under test 500 is automatically completed according to the preset test sequence. When setting the test sequence, the specific test sequence can be, but is not limited to, AC power supply test, communication test, parameter setting test (CMU parameter setting, CMU address bit setting), daisy chain test, software version reading test, parameter setting test (time setting), temperature test, insulation resistance test, reverse polarity test, 300V open-loop test, 1400V open-loop test, short-circuit loop test, VSG test (virtual synchronous generator test), and overvoltage test. The same test items can also be repeated by adjusting parameters or other control factors. The specific settings can be made according to actual conditions and are not limited here.

[0118] Reference Figure 2 In one embodiment, the plurality of functional test branches 201 include an insulation impedance test branch, the insulation impedance test branch includes a resistor plate 230, the connection interface 110 includes a DC power port, the first connection terminal of the resistor plate 230 is used to connect to the positive terminal of the converter under test 500 through the positive terminal of the DC power port, the second connection terminal of the resistor plate 230 is used to connect to the negative terminal of the converter under test 500 through the negative terminal of the DC power port, and the third connection terminal of the resistor plate 230 is used to connect to the ground terminal of the converter under test 500.

[0119] The resistor board 230 is used to output a DC high voltage test signal to the converter under test 500, so that the converter under test 500 outputs a corresponding insulation impedance signal according to the DC high voltage test signal. The control circuit module 400 is used to output a second alarm signal according to the insulation impedance signal.

[0120] During insulation impedance testing, the received feedback signal is the insulation impedance signal. Insulation impedance testing is used to detect the insulation performance between the chassis of the converter under test (500) and ground. Good insulation performance can reduce leakage or short-circuit accidents during electrical equipment operation, ensuring safe operation. The design of the resistance plate 230 allows the test current to flow within a controllable range, reducing test errors and improving the accuracy of insulation impedance testing. When the insulation impedance value is lower than the safety standard, the system will promptly issue a fault signal, enabling operators to quickly locate the problem, such as checking for insulation damage or proper grounding, thereby preventing further deterioration of the fault to some extent.

[0121] Reference Figure 2 In one embodiment, the resistor plate 230 includes two aluminum-cased resistors connected in series.

[0122] Optionally, a contactor KZ9, a resistor plate 230, and a contactor KZ10 are connected in series between the first output terminal block S1 and the second output terminal block S2. The resistor plate 230 includes two aluminum-cased resistors connected in series. The two aluminum-cased resistors are connected to the OUT-PE (Output Protective Earth) of the converter 500 under test chassis. The insulation resistance of the converter 500 chassis is tested through the positive and negative terminals of the test device. During the test, a DC voltage (such as 1KV-1.5KV or other suitable DC voltages for actual testing) is applied to the converter 500 chassis through the positive and negative terminals of the test device. Specifically, when the DC voltage is 1KV-1.5KV, the DC resistance to ground is checked to see if it meets the requirements. If it does not meet the requirements, a second alarm signal is output, such as a fault signal indicating low ISO insulation resistance.

[0123] Reference Figure 9 In one embodiment, the multiple functional test branches 201 include a temperature test branch, which is used to detect the test environment temperature. The control circuit module 400 is used to output test results based on the test environment temperature and the temperature feedback signal transmitted by the converter under test 500.

[0124] Understandably, the converter under test (DUT) 500 will be equipped with temperature detection devices such as AC relays, bus electrolytic capacitors, module NTCs, AC film capacitors, and DC film capacitors, including temperature sensors, to detect temperature and transmit corresponding temperature feedback signals to the testing device. The temperature detection branch is used to measure the ambient temperature (internal temperature of the testing device), and the control circuit module 400 outputs test results based on the ambient temperature and the temperature feedback signal transmitted by the DUT 500. Specifically, the control circuit module 400 obtains the temperature of the DUT 500 based on the received temperature feedback signal. When the temperature difference between the ambient temperature and the DUT temperature is within the range of 0–30°C (or other temperature ranges), it determines that the DUT 500's heat dissipation function is normal; when the temperature difference exceeds the range of 0–30°C (or other temperature ranges), it determines that the DUT 500's heat dissipation function is abnormal. Specific settings can be configured according to actual conditions and are not limited here.

[0125] It should be noted that the transformer 210, bidirectional DC source 220 and other devices in the aforementioned multiple functional test branches 201 can be used together; or they can be set separately for multiple different functional test branches 201; the specific settings can be determined according to actual conditions, and are not limited here.

[0126] Reference Figure 2 In one embodiment, the testing apparatus further includes a cooling fan for operation when the testing apparatus is connected to an AC power source.

[0127] Because the testing device contains numerous electrical components, and the bidirectional DC power source 220 generates significant heat during operation, this application employs a cabinet-top fan mounted on the testing fixture platform or other testing equipment as a cooling fan to address the heat dissipation problem and prevent issues such as excessive internal temperature and component burnout caused by overheating. Optionally, the cooling fan includes fan FS1 and fan FS2; the two power terminals of fan FS1 and fan FS2 are connected in parallel to the second terminal of circuit breaker Q2 to connect to AC power. When circuit breaker Q2 closes and the testing device begins operation, the cooling fan is simultaneously activated for heat dissipation.

[0128] Reference Figure 9 In one embodiment, the multiple functional test branches 201 include a communication test branch, and there are multiple connection interfaces 110. The multiple connection interfaces 110 include at least one or more of the following: network communication interface, CAN communication interface, daisy chain communication interface, RS485 communication interface.

[0129] The communication test branch is connected to the connection interface 110. The communication test branch is used to output the corresponding communication test signal when the converter under test 500 is connected to each connection interface 110, and to receive the corresponding test feedback signal output by the converter under test 500 in response to the test signal. The control circuit module 400 is specifically used to output the test result according to the received communication test feedback signal.

[0130] Establish a communication connection with the converter under test 500 through the network communication interface, CAN communication interface, daisy-chain communication interface, RS485 communication interface, etc. of the test device to verify whether the functions of these interfaces are normal.

[0131] like Figure 10 As shown, the communication test branch includes a communication module. Taking daisy-chain testing as an example, the communication module includes multiple daisy-chain communication branches matched with different converters under test 500. Each daisy-chain communication branch includes a daisy-chain communication PCB board and other functional boards. The operation of different daisy-chain communication PCB boards is switched via contactors. Specifically, the model of the converter under test 500 can be determined based on the received parameters of the converter under test, and the connected daisy-chain communication PCB board is switched according to the model of the converter under test 500 to save time on material replacement. The embodiments of this application include the daisy-chain PCB boards shown in P1 and P2, corresponding to different models of converters under test, and are operated via contactors as shown in the diagram. Figure 11 , Figure 12 , Figure 13 The daisy-chain function board shown enables daisy-chain testing for different models, and multiple communication interfaces are used for communication with, for example, […]. Figure 11 , Figure 12 , Figure 13 The functional board connections are shown. In some embodiments, the switching circuit module 300 includes, as shown in the diagram. Figures 14(a) to 14(d) The diagram shows multiple daisy-chain switching loops provided for different models. These loops are used to achieve multi-level switching for different models, and daisy-chain testing for the corresponding models is achieved through daisy-chain switching loop control.

[0132] like Figure 15 As shown, the communication test includes network port communication test. Taking the network port communication test as an example, the function boards P3 and P4 are used to implement the switch function, which is used to read relevant data from the State Grid and to further realize network port communication.

[0133] like Figure 15 As shown, the communication test includes Bluetooth communication test. Taking Bluetooth communication test as an example, Bluetooth communication is realized through function board P5, and communication conversion is realized through communication conversion board P6.

[0134] The switching circuit module 300 controls the connection between different function boards and their corresponding communication board interfaces to perform communication tests on the corresponding function boards. The communication test branch outputs corresponding communication test signals to the converter under test (DUT) 500 when each connection interface 110 is connected to the DUT 500, and receives corresponding test feedback signals output by the DUT 500 in response to the test signals. The control circuit module 400 specifically verifies the correctness of the communication protocol, the integrity of data transmission, and the response time based on the received communication test feedback signals, and outputs the test results.

[0135] like Figure 16 As shown, optionally, indicator boards or other indicators can be set for specific communication interfaces such as network communication interfaces, CAN communication interfaces, daisy-chain communication interfaces, and RS485 communication interfaces to verify whether these interfaces are functioning normally. For example, an external indicator board for the communication function of the corresponding communication interface can be used. If, during the test, the indicator light on the external indicator board matches the indicator light on the converter under test 500 used to indicate the corresponding communication function, it indicates that the communication of the corresponding communication interface is normal.

[0136] like Figure 16 , Figure 17 As shown, in some embodiments of this application, the control circuit module 400 implements communication testing through a communication test branch, and through the communication test branch, Figure 16 , Figure 17 The interface receives control signals from external sources (such as user input, host computer control commands, sensor signals, etc.) and transmits these signals to the switching circuit module 300 via electrical connection. Based on the received signals, the control circuit module 400 controls the switching circuit module 300 to operate, thereby completing various tests and automatic switching between different test functions.

[0137] Reference Figure 10 In one embodiment, the multiple functional test branches 201 include a daisy-chain test branch, and the connection interface 110 includes a daisy-chain communication interface. The daisy-chain test branch is used to connect to the connected converter under test 500 to form a ring circuit through the daisy-chain communication interface. The control circuit module 400 is specifically used to receive the onboard temperature signal of the product under test through the ring circuit.

[0138] like Figure 12 , Figure 12 , Figure 13As shown, the test setup includes a BMU fixture. The connection interface 110 includes terminals on the BMU fixture. Terminals on the panel of the converter under test (DUT) 500 are connected to some terminals on the BMU fixture, and other terminals on the panel of the DUT 500 are connected to other terminals on the BMU fixture, forming a loop circuit. After connecting the daisy chain, the onboard temperature information of the BMU is read through the CMU. The ability to read a normal temperature value indicates that the CMU daisy chain communication is normal. Here, CMU (Communication Management Unit) daisy chain communication refers to the use of a daisy chain topology in a BMS (Battery Management System) or other systems requiring distributed data communication to achieve data communication between the CMU and other devices (such as the Battery Management Unit (BMU)). Daisy chain communication, as a network topology, is typically used to connect multiple devices in a linear sequence. In a BMS system, the CMU communicates sequentially with each BMU via daisy chain communication, with data transmitted from the initial CMU to the next CMU.

[0139] In this embodiment, verification is performed before communication testing, including the following steps: First, power is supplied to the main control board of the converter under test 500 (e.g., 24V). The test device communicates with the converter under test 500 via Ethernet, CAN, daisy-chain, and RS485 communication, respectively realizing the function of a test switch. The converter under test 500's CMU reads the product's internal software version number. The daisy-chain test branch is connected to the connected converter under test 500 through the daisy-chain communication interface to form a ring circuit (e.g., the terminals HP1 and HN1 on the panel of the converter under test 500 are connected to the terminal J5 of the first BMU on the BMU fixture, and the terminals LP1 and LN1 on the panel of the converter under test 500 are connected to the terminal J6 of the last BMU on the BMU fixture as the output terminal). After connecting the daisy chain, the onboard temperature information of the BMU is read through the CMU. If a normal temperature value can be read, it indicates that the CMU daisy-chain communication is normal. Specifically, an external light board can be used to correspond to the communication function of the communication interface. Taking the light board corresponding to the RS485 communication interface as an example, the RS485 communication interface is connected to the external light board. If the indicator light on the external light board and the indicator light on the converter under test 500 that indicates the RS485 communication function are consistent during the test, it means that the RS485 communication is normal.

[0140] The testing apparatus of this application can be used to implement any one or more of the following schemes:

[0141] AC power supply test of the converter:

[0142] The first end of transformer 210 is connected to an AC power source. The second end of transformer 210 has multiple secondary windings, each connected to an AC power source port. Each secondary winding outputs a test AC current of a corresponding voltage level to the AC side of the converter under test (PCS) 500, enabling the PCS 500 to output a corresponding AC power supply test feedback signal based on the received test AC current. Different voltages (400V, 480V, 690V, and 800V) output by transformer 210 are used to adapt to different PCS 500s and simulate different power qualities. The AC power supply test provides test power to the PCS 500, simulating different voltage, frequency, and load conditions in a real power grid environment to test the performance and stability of the PCS 500.

[0143] Communication testing, primarily used to test network port communication under AC power supply conditions:

[0144] The test device establishes communication connections with the converter under test (DUT) 500 through its network communication interface, CAN communication interface, daisy-chain communication interface, and RS485 communication interface to verify the functionality of these interfaces. This is used to test the communication capabilities of the DUT 500, including communication protocol compatibility, data transmission accuracy, and stability.

[0145] Parameter setting test, including CMU parameter settings, CMU address bit settings, and time settings.

[0146] CMU parameter settings:

[0147] Connect the test device and the CMU (Communication Management Unit) using a communication cable (such as RS232, RS485, or Ethernet cable). The test device sends parameter setting commands to the CMU through the communication interface and reads the current configuration of the CMU to verify whether the software version number inside the converter under test 500 product meets the test requirements.

[0148] CMU address settings:

[0149] The correctness of the CMU address settings is verified by sending an address query command to the CMU and verifying whether the returned address matches the expectation.

[0150] Time settings:

[0151] The control circuit module 400 sets the time parameters, sends a time setting command to the converter under test 500, and verifies whether the time of the converter under test 500 is consistent with the expectation.

[0152] The parameter setting test allows the parameters of the converter 500 under test to be configured and adjusted, verifying its ability to correctly receive and apply external parameter settings, such as CMU parameters, address bits, and time, to ensure the flexibility and configurability of its operating status.

[0153] Daisy chain test:

[0154] A ring structure is formed by connecting BMUs (Battery Management Units or other modules). Specifically, the HP1 and HN1 terminals on the panel of the inverter under test (DUT) 500 are connected to the J5 terminal of the first BMU on the BMU fixture, and the LP1 and LN1 terminals on the panel of the DUT 500 are connected to the J6 terminal of the last BMU on the BMU fixture as the output terminals. After connecting the daisy chain, the onboard temperature information of the BMU is read through the CMU. If a normal temperature value is read, it indicates that the CMU daisy chain communication is normal. The daisy chain test is used to test the communication function of the DUT 500 under daisy chain connection, improving the stability and accuracy of signal transmission in multi-device connection scenarios.

[0155] Software version reading test:

[0156] The Communication Management Unit (CMU) is used to communicate with the converter under test (DUT) 500. A software version query command is sent to the DUT 500 to read the internal software version number and verify the accuracy of the returned version information. The software version read test is used to read the software version information of the DUT 500 and confirm that the running software version is compatible with the requirements or the current system and application.

[0157] Temperature test:

[0158] The converter under test (DUT) 500 is equipped with temperature detection devices such as AC relays, bus electrolytic capacitors, module NTCs, AC film capacitors, and DC film capacitors, including temperature sensors, to detect temperature and transmit corresponding temperature feedback signals to the testing device. The temperature detection branch is used to test the ambient temperature (the internal ambient temperature of the testing device), and the control circuit module 400 outputs test results based on the ambient temperature and the temperature feedback signal transmitted by the DUT 500. Temperature testing is used to detect temperature changes during the operation of the DUT 500, ensuring it operates within a safe temperature range and preventing overheating to some extent.

[0159] Insulation resistance test:

[0160] During testing, a DC voltage (such as 1KV-1.5KV or other suitable DC voltages) is applied to the chassis of the converter 500 under test through the positive and negative terminals of the testing device. Specifically, when the DC voltage is 1KV-1.5KV, the DC-to-ground resistance is checked to see if it meets the requirements. If it does not meet the requirements, a second alarm signal is output, such as a low ISO insulation resistance fault signal. The insulation resistance test is used to detect the insulation resistance of the converter, ensuring that its electrical insulation performance meets safety standards and preventing electrical leakage and short circuits to a certain extent.

[0161] Reverse polarity test:

[0162] By configuring contactors KZ25, KZ26, KZ27, and KZ28 in combination, positive and negative polarity switching can be achieved to perform polarity reverse connection tests on the product under test. All contactors are controlled by a host computer for on / off switching, enabling automated testing. The polarity reverse connection test simulates a polarity reverse connection fault, testing the converter's protection functions and response capabilities.

[0163] Open-loop testing, primarily used for 300V and 1400V open-loop testing.

[0164] Multiple secondary windings with different rated voltages are installed on transformer 210, which can accommodate multiple different models of test products. It can also detect whether the various hardware and software components of the product are functioning properly, completing open-loop testing without feedback, thus enabling open-loop testing at different voltage levels. Open-loop testing is used to test the output response of the converter under test 500 under open-loop conditions, evaluating its performance without feedback control.

[0165] Short-circuit loop test:

[0166] The AC power port includes three phase interfaces, with a short-circuit loop test branch connected between them. This branch simulates short-circuit conditions to test the protection functions and response capabilities of the converter under test (DUT) 500 during a short circuit.

[0167] Virtual Synchronous Generator (VSG) Testing:

[0168] By setting up a bidirectional DC source 220 to convert AC to DC power, grid-connected testing of the converter under test (DUT) 500 product is achieved. VSG technology is used to simulate the inertia and damping characteristics of a traditional synchronous generator, enabling the converter to better adapt to dynamic changes in the grid during grid connection, thus improving grid stability and reliability. The virtual synchronous generator test branch is used to simulate the operating characteristics of a synchronous generator VSG, testing the performance of the DUT 500 in grid-connected scenarios with a synchronous generator or similar applications.

[0169] Overvoltage test:

[0170] The overvoltage test branch simulates overvoltage conditions to test the protection capability and stability of the converter under test (DUT) 500. The reverse polarity test branch simulates a reverse polarity fault to test the converter's protection function and response capability.

[0171] The above description is merely an exemplary embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the technical concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A testing device, characterized in that, include: Connection interface (110), the connection interface (110) is used to connect the converter under test (500); The test circuit module (200) includes multiple functional test branches (201). Each functional test branch (201) is used to output a corresponding test signal to the connected converter under test (500) through the connection interface (110) and receive a corresponding test feedback signal output by the converter under test (500) in response to the test signal. A switching circuit module (300) has multiple output terminals connected to each of the functional test branches (201); A control circuit module (400) is connected to the input terminal of the switching circuit module (300). The control circuit module (400) controls the switching circuit module (300) to connect with the corresponding functional test branch (201) so that the corresponding functional test branch (201) works and outputs test results according to the received test feedback signal.

2. The testing apparatus as described in claim 1, characterized in that, The connection interface (110) includes an AC power port, and one of the multiple functional test branches (201) includes an AC power supply test branch. The AC power supply test branch includes a transformer (210). The first end of the transformer (210) is used to connect to an AC power source. The second end of the transformer (210) is provided with multiple secondary windings. The multiple secondary windings are connected to the AC power port. Each secondary winding is used to output a test AC current of the corresponding voltage level to the AC side of the converter under test (500), so that the converter under test (500) outputs a corresponding AC power supply test feedback signal according to the received test AC current.

3. The testing apparatus as described in claim 2, characterized in that, The transformer (210) has a primary winding at its first end, and the switching circuit module (300) includes an overcurrent protection circuit. The primary winding is connected to an AC power source through the overcurrent protection circuit.

4. The testing apparatus as described in claim 1, characterized in that, The connection interface (110) includes an AC power port, and the multiple functional test branches (201) also include a short-circuit loop test branch; The AC power port includes three phase interfaces, and the short-circuit loop test branch is connected between the three phase interfaces. The short-circuit loop test branch is used to output a short-circuit test signal to the converter under test (500), so that the converter under test (500) outputs a short-circuit test feedback signal according to the short-circuit test signal. The control circuit module (400) is used to output a first alarm signal according to the short-circuit test feedback signal.

5. The testing apparatus as described in claim 2, characterized in that, The connection interface (110) includes a DC power port. Among the multiple functional test branches (201), there is an overvoltage test branch. The overvoltage test branch includes a bidirectional DC source (220). The input end of the bidirectional DC source (220) is used to connect to an AC power source, and the output end is connected to the DC power port. It is used to convert the AC power from the AC power source into test DC power and output it to the DC side of the converter under test (500) through the DC power port, so that the converter under test (500) outputs a corresponding overvoltage test feedback signal according to the received test DC power.

6. The testing apparatus as described in claim 2, characterized in that, The connection interface (110) includes a DC power port, and among the multiple functional test branches (201) is a polarity reverse test branch, which includes a bidirectional DC source (220). The switching circuit module (300) includes a forward selection branch and a reverse selection branch. The input terminals of the forward selection branch and the reverse selection branch are respectively connected to the output terminal of the bidirectional DC source (220), and the output terminals of the forward selection branch and the reverse selection branch are respectively connected to the DC power port. When the forward selection branch is closed and the reverse selection branch is open, a positive test voltage is output to the converter under test (500) through the bidirectional DC source (220); When the forward selection branch is open and the reverse selection branch is closed, a reverse test voltage is output to the converter under test (500) through the bidirectional DC source (220).

7. The testing apparatus as described in claim 6, characterized in that, The DC power supply port includes a first positive terminal (DC1+), a first negative terminal (DC1-), a second positive terminal (DC2+), and a second negative terminal (DC2-); Wherein, the first positive terminal (DC1+) and the first negative terminal (DC1-) constitute the first DC power supply circuit, and the second positive terminal (DC2+) and the second negative terminal (DC2-) constitute the second DC power supply circuit; The polarity reverse connection test branch includes a first output terminal block (S1) and a second output terminal block (S2). The first output terminal block (S1) is connected to the first positive terminal (DC1+) and the second positive terminal (DC2+). The second output terminal block (S2) is connected to the first negative terminal (DC1-) and the second negative terminal (DC2-). The forward selection branch includes a first relay (KZ1) and a second relay (KZ2), and the reverse selection branch includes a third relay (KZ3) and a fourth relay (KZ4). The positive terminal of the bidirectional DC source (220) is connected to the first terminal of the first relay (KZ1) and the first terminal of the third relay (KZ3), respectively. The negative terminal of the bidirectional DC source (220) is connected to the first terminal of the second relay (KZ2) and the first terminal of the fourth relay (KZ4), respectively. The second terminals of the first relay (KZ1) and the second terminals of the second relay (KZ2) are connected to the first output terminal block (S1), respectively. The second terminals of the third relay (KZ3) and the second terminals of the fourth relay (KZ4) are connected to the second output terminal block (S2), respectively.

8. The testing apparatus as described in claim 5, characterized in that, The test circuit module (200) also includes an isolation circuit. The output terminal of the isolation circuit is connected to the input terminal of the bidirectional DC source (220) and the input terminal of the transformer (210), respectively. The input terminal of the isolation circuit is used to connect to an AC power source.

9. The testing apparatus as described in claim 5, characterized in that, The test circuit module (200) also includes a test load, which is used to discharge the electrical energy of the converter under test (500); The control circuit module (400) is specifically used to control the test load to work after receiving the test completion signal.

10. The testing apparatus as described in claim 1, characterized in that, The multiple functional test branches (201) include a communication test branch, and there are multiple connection interfaces (110). The multiple connection interfaces (110) include at least one of network communication interface, CAN communication interface, daisy chain communication interface, and RS485 communication interface. The communication test branch is connected to the connection interface (110). The communication test branch is used to output the corresponding communication test signal when the converter under test (500) is connected to each of the connection interfaces (110), and to receive the corresponding test feedback signal output by the converter under test (500) in response to the test signal. The control circuit module (400) is specifically used to output the test result according to the received communication test feedback signal.

11. The testing apparatus as described in claim 1, characterized in that, The multiple functional test branches (201) include a daisy-chain test branch, the connection interface (110) includes a daisy-chain communication interface, the daisy-chain test branch is used to connect to the connected converter under test (500) through the daisy-chain communication interface to form a ring circuit, and the control circuit module (400) is specifically used to receive the onboard temperature signal of the product under test through the ring circuit.

12. The testing apparatus as described in any one of claims 1 to 11, characterized in that, The multiple functional test branches (201) include an insulation impedance test branch, which includes a resistor plate (230). The connection interface (110) includes a DC power port. The first connection end of the resistor plate (230) is used to connect to the positive terminal of the converter under test (500) through the positive terminal of the DC power port. The second connection end of the resistor plate (230) is used to connect to the negative terminal of the converter under test (500) through the negative terminal of the DC power port. The third connection end of the resistor plate (230) is used to connect to the ground terminal of the converter under test (500). The resistor plate (230) is used to output a DC high voltage test signal to the converter under test (500), so that the converter under test (500) outputs a corresponding insulation impedance signal according to the DC high voltage test signal, and the control circuit module (400) is used to output a second alarm signal according to the insulation impedance signal.

13. The testing apparatus as described in claim 12, characterized in that, The resistor plate (230) includes two aluminum-cased resistors connected in series.

14. The testing apparatus as described in any one of claims 1 to 11, characterized in that, The multiple functional test branches (201) include a temperature test branch, which is used to detect the test environment temperature. The control circuit module (400) is used to output test results based on the test environment temperature and the temperature feedback signal transmitted by the converter under test (500).

15. The testing apparatus as described in any one of claims 1 to 11, characterized in that, The testing device also includes a cooling fan, which is used to operate when the testing device is connected to an AC power source.

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