Start-up method, device and system of converter test system and storage medium

Abstract

The application relates to a starting method and device of a converter test system, the converter test system, a computer readable storage medium and a computer program product. The converter comprises a measured module and a measured module connected thereto; the converter test system comprises a power supply module for accessing an external DC voltage, and the power supply module is connected to the measured module and the measured module; the method comprises the following steps: in the case that the capacitor voltage of the power supply module reaches a preset first target voltage, controlling the power supply module to output a preset negative voltage to the measured module via the measured module to charge the measured module; in the case that the capacitor voltage of the measured module reaches a preset second target voltage, controlling the power supply module to output a positive voltage to the measured module, and controlling the measured module to output a measured voltage to the measured module to charge the measured module until the capacitor voltage of the measured module reaches a preset third target voltage, and the charging starting of the converter test system is completed. Therefore, the cost of the test system can be reduced.

Description

Technical Field

[0001] This application relates to the field of electronic power technology, and in particular to a starting method, apparatus, converter test system, computer-readable storage medium, and computer program product for a converter test system. Background Technology

[0002] Modular multilevel converters (MMCs) have become core components in the field of high-voltage flexible direct current transmission due to their high degree of modularity, good harmonic characteristics, and ease of expansion. To reduce the construction cost of MMCs, a hybrid structure using switching valves and switched capacitor valves has been proposed in recent years. This structure can significantly reduce the number of active switching devices, thereby reducing manufacturing costs and operating losses.

[0003] In the engineering verification phase, traditional back-to-back test platforms cannot directly meet the operational capability verification needs of these novel topologies due to significant differences in working mechanisms, voltage stress, current stress, and energy coupling methods between switching valves and other converter valves such as switched capacitor valves. To verify the operational capability of converter valves under different operating conditions, it is typically necessary to build a test system containing multiple independent power supplies, which then power and control multiple test modules within the test system. However, using multiple power supplies complicates the test system structure, increases hardware costs, and makes it difficult to apply to real-world scenarios. Summary of the Invention

[0004] Therefore, it is necessary to provide a converter test system startup method, device, converter test system, computer-readable storage medium, and computer program product that can reduce the construction cost of the test system while providing power supply and control for the switching devices in the converter test system.

[0005] In a first aspect, this application provides a startup method for a converter test system, wherein the converter includes a module under test (DUT) and a support module connected to the DUT; the converter test system includes a power supply module for connecting an external DC voltage, the power supply module being connected to both the DUT and the support module; the method includes:

[0006] Obtain the capacitor voltage of the power replenishment module;

[0007] When the capacitor voltage of the power supply module reaches the preset first target voltage, the power supply module is controlled to output a preset negative voltage to the auxiliary test module through the module under test to charge the auxiliary test module; the module under test is short-circuited and conducts under negative voltage.

[0008] Obtain the capacitor voltage of the test module;

[0009] When the capacitor voltage of the test module reaches the preset second target voltage, the charging module is controlled to output a positive voltage to the module under test, and the test module is controlled to output a test voltage to the module under test. The module under test is charged by positive voltage and DC voltage until the capacitor voltage of the module under test reaches the preset third target voltage, thus completing the charging start-up of the converter test system.

[0010] In one embodiment, the auxiliary testing module includes multiple first half-bridge sub-modules connected in series, with the first and last ends of the series connection of the multiple first half-bridge sub-modules connected to the module under test and the power supply module, respectively; controlling the power supply module to output a preset negative voltage to the auxiliary testing module via the module under test includes:

[0011] The control power supply module outputs a preset negative voltage to the auxiliary test module via the test module to charge the first input sub-module in the auxiliary test module. The first input sub-module is the first half-bridge sub-module in the input state.

[0012] Obtain the first total capacitor voltage of the first capacitor voltage in each first input submodule;

[0013] When the first total capacitor voltage reaches a preset first charging limit, a first preset number of first input sub-modules are bypassed, wherein the first charging limit corresponds to the number of first input sub-modules.

[0014] In one embodiment, the control power supply module outputs a preset negative voltage to the auxiliary test module via the module under test, including:

[0015] Obtain the first capacitor voltage of each first input submodule and the second capacitor voltage of each first bypass submodule. The first bypass submodule is the first half-bridge submodule in the bypass state.

[0016] The sum of the voltages of each first capacitor and each second capacitor is taken as the capacitor voltage of the test module.

[0017] During the preset control cycle, the first input submodule with the largest first capacitor voltage is bypassed, and the first bypass submodule with the smallest second capacitor voltage is input, until the capacitor voltage of the test module reaches the preset second target voltage.

[0018] In one embodiment, the test module includes multiple first half-bridge sub-modules connected in series, with the first and last ends of the series connection of the multiple first half-bridge sub-modules connected to the module under test and the power supply module, respectively; controlling the test module to output a test voltage to the module under test includes:

[0019] According to the preset time interval, each first half-bridge submodule is switched to the working state in sequence, and the test voltage is output to the module under test through the first half-bridge submodule in the working state.

[0020] In one embodiment, the module under test includes multiple bridge arms connected according to a preset topology. The positive and negative ports of the multiple bridge arms connected according to the preset topology are respectively connected to the power supply module and the module under test. The bridge arms include multiple second half-bridge sub-modules connected in series. Charging the module under test with positive voltage and DC voltage includes:

[0021] The second input submodule in each bridge arm of the module under test is charged by positive voltage and DC voltage. The second input submodule is the second half-bridge submodule in the input state.

[0022] For each bridge arm, the second total capacitor voltage of the third capacitor voltage of each second input submodule in the bridge arm is obtained. When the second total capacitor voltage reaches the preset second charging upper limit, the second preset number of second input submodules in the bridge arm are bypassed, wherein the second charging upper limit corresponds to the number of second input submodules in the bridge arm.

[0023] In one embodiment, charging the module under test using a positive voltage and a DC voltage includes:

[0024] Obtain the third capacitor voltage of each second input submodule and the fourth capacitor voltage of each second bypass submodule. The second bypass submodule is the second half-bridge submodule in the bypass state.

[0025] The sum of the voltages of each third capacitor and each fourth capacitor is taken as the capacitor voltage of the module under test.

[0026] For each bridge arm, within a preset control cycle, the second input submodule with the largest third capacitor voltage in the bridge arm is bypassed, and the second bypass submodule with the smallest fourth capacitor voltage in the bridge arm is input, until the capacitor voltage of the module under test reaches the preset third target voltage.

[0027] In one embodiment, the test module includes multiple first half-bridge sub-modules connected in series, with the first and last ends of the series connection of the multiple first half-bridge sub-modules connected to the module under test and the power replenishment module, respectively; after completing the charging start-up of the converter test system, the method further includes:

[0028] Obtain the voltage of the fifth capacitor of each first half-bridge submodule and obtain the test current flowing through the test module;

[0029] When the test current is positive, each first half-bridge submodule is switched to the engaged state in sequence according to the voltage of the fifth capacitor from small to large.

[0030] When the test current is negative, each first half-bridge submodule is switched to the working state in sequence according to the voltage of the fifth capacitor from large to small.

[0031] Secondly, this application also provides a starting device for a converter test system, wherein the converter includes a module under test and a supporting test module connected to the module under test; the converter test system includes a power supply module for connecting an external DC voltage, the power supply module being connected to both the module under test and the supporting test module; the device includes:

[0032] The first acquisition module is used to acquire the capacitor voltage of the energy replenishment module;

[0033] The first charging module is used to control the charging module to output a preset negative voltage to the auxiliary test module through the tested module when the capacitor voltage of the charging module reaches the preset first target voltage, so as to charge the auxiliary test module; the tested module is short-circuited and turned on under the negative voltage.

[0034] The second acquisition module is used to acquire the capacitor voltage of the test module;

[0035] The second charging module is used to control the energy replenishment module to output a positive voltage to the module under test when the capacitor voltage of the auxiliary module reaches the preset second target voltage, and to control the auxiliary module to output an auxiliary voltage to the module under test. The module under test is charged by positive voltage and DC voltage until the capacitor voltage of the module under test reaches the preset third target voltage, thus completing the charging start-up of the converter test system.

[0036] Thirdly, this application also provides a converter test system, including a control module and a power supply module for connecting an external DC voltage. The power supply module is also used to connect the module under test and the auxiliary test module in the converter. The module under test is also connected to the auxiliary test module. The control module is connected to the power supply module, the auxiliary test module and the module under test respectively.

[0037] The power supply module is used to connect to an external DC voltage to power the power supply module.

[0038] The control module is used to implement the following steps:

[0039] Obtain the capacitor voltage of the power replenishment module;

[0040] When the capacitor voltage of the power supply module reaches the preset first target voltage, the power supply module is controlled to output a preset negative voltage to the auxiliary test module through the module under test to charge the auxiliary test module; the module under test is short-circuited and conducts under negative voltage.

[0041] Obtain the capacitor voltage of the test module;

[0042] When the capacitor voltage of the test module reaches the preset second target voltage, the charging module is controlled to output a positive voltage to the module under test, and the test module is controlled to output a test voltage to the module under test. The module under test is charged by positive voltage and DC voltage until the capacitor voltage of the module under test reaches the preset third target voltage, thus completing the charging start-up of the converter test system.

[0043] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the following steps:

[0044] Obtain the capacitor voltage of the power replenishment module;

[0045] When the capacitor voltage of the power supply module reaches the preset first target voltage, the power supply module is controlled to output a preset negative voltage to the auxiliary test module through the module under test to charge the auxiliary test module; the module under test is short-circuited and conducts under negative voltage.

[0046] Obtain the capacitor voltage of the test module;

[0047] When the capacitor voltage of the test module reaches the preset second target voltage, the charging module is controlled to output a positive voltage to the module under test, and the test module is controlled to output a test voltage to the module under test. The module under test is charged by positive voltage and DC voltage until the capacitor voltage of the module under test reaches the preset third target voltage, thus completing the charging start-up of the converter test system.

[0048] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, performs the following steps:

[0049] Obtain the capacitor voltage of the power replenishment module;

[0050] When the capacitor voltage of the power supply module reaches the preset first target voltage, the power supply module is controlled to output a preset negative voltage to the auxiliary test module through the module under test to charge the auxiliary test module; the module under test is short-circuited and conducts under negative voltage.

[0051] Obtain the capacitor voltage of the test module;

[0052] When the capacitor voltage of the test module reaches the preset second target voltage, the charging module is controlled to output a positive voltage to the module under test, and the test module is controlled to output a test voltage to the module under test. The module under test is charged by positive voltage and DC voltage until the capacitor voltage of the module under test reaches the preset third target voltage, thus completing the charging start-up of the converter test system.

[0053] The aforementioned converter test system's startup method, apparatus, system, computer-readable storage medium, and computer program utilize a single external DC voltage source to pre-charge the power supply module, bringing its capacitor voltage to a first target voltage. Subsequently, the power supply module outputs a negative voltage, which, through the short-circuit conduction path within the module under test (DUT), directly and uncontrolledly charges the auxiliary module, allowing it to obtain startup energy without an independent power supply. Once the auxiliary module's capacitor voltage reaches a second target voltage, the power supply module switches to positive voltage output, simultaneously controlling the auxiliary module to output a supplementary voltage to the DUT. The combined positive and supplementary voltages charge the DUT, ultimately bringing its capacitor voltage to a third target voltage. The entire charging process relies on only one external power supply providing external DC voltage. By utilizing the DUT's conduction characteristics and the auxiliary module's voltage output capability in stages, all modules can be powered up sequentially. The system structure is simple, requiring fewer external DC voltage sources. Therefore, while ensuring the converter test system starts up normally and powers each module, the hardware construction cost of the test system is reduced, thus improving the system's versatility. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 This is an application environment diagram of the start-up method of the converter test system in one embodiment;

[0056] Figure 2 This is a schematic diagram of the energy replenishment module in a converter test system in one embodiment;

[0057] Figure 3 This is a schematic diagram of the structure of the first half-bridge submodule in the test module of the converter test system in one embodiment;

[0058] Figure 4 This is a schematic diagram of the converter test system in one embodiment;

[0059] Figure 5 This is a schematic diagram of the structure of the second half-bridge submodule in the converter test system of one embodiment;

[0060] Figure 6 This is a flowchart illustrating the startup method of a converter test system in one embodiment;

[0061] Figure 7 This is a detailed flowchart illustrating the process of controlling the energy replenishment module to output a preset negative voltage to the auxiliary test module via the module under test in one embodiment.

[0062] Figure 8 This is a detailed flowchart illustrating the process of controlling the power supply module to output a preset negative voltage to the auxiliary test module via the module under test in another embodiment.

[0063] Figure 9 This is a detailed flowchart illustrating the charging process of the module under test using positive voltage and DC voltage in one embodiment.

[0064] Figure 10 This is a detailed flowchart illustrating the charging process of the module under test using positive voltage and DC voltage in another embodiment.

[0065] Figure 11 This is a flowchart illustrating the startup method of a converter test system in one embodiment;

[0066] Figure 12 This is a structural block diagram of the start-up device of a converter test system in one embodiment;

[0067] Figure 13 This is an internal structural diagram of a converter test system in one embodiment. Detailed Implementation

[0068] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0069] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0070] Modular multilevel converters (MMCs) have become core components in the field of high-voltage flexible direct current transmission due to their high degree of modularity, good harmonic characteristics, and ease of expansion. To reduce the construction cost of MMCs, a hybrid structure using switching valves and switched capacitor valves has been proposed in recent years. This structure can significantly reduce the number of active switching devices, thereby reducing manufacturing costs and operating losses.

[0071] Specifically, in traditional modular multilevel converters, each half-bridge or full-bridge submodule requires an independent active switching device (such as an IGBT) to achieve voltage output and capacitor voltage balancing. Since each submodule must participate in voltage regulation and voltage equalization control, the number of active switching devices increases proportionally with the number of submodules as the number of levels increases. However, in a hybrid structure combining a switching valve and a switched-capacitor valve, the switched-capacitor valve is used to achieve voltage self-balancing or energy buffering. It redistributes energy among the multiple submodules of the switching valve through the switching of the capacitor series-parallel network, thereby automatically aligning the capacitor voltages of each submodule. In this way, the submodules in the switching valve no longer need to perform complex active voltage equalization control individually; their active switching devices can be used solely for main power transmission, or even a simpler topology can be adopted (e.g., using only two switching devices instead of four). Therefore, by introducing a shared switched-capacitor valve, the entire converter replaces the voltage equalization-related active devices that were originally required independently by each submodule, thus significantly reducing the total number of active switching devices.

[0072] In the engineering verification phase, traditional back-to-back test platforms cannot directly meet the operational capability verification needs of these novel topologies due to significant differences in working mechanisms, voltage stress, current stress, and energy coupling methods between switching valves and other converter valves such as switched capacitor valves. To verify the operational capabilities of converter valves under different operating conditions, it is typically necessary to build a test system containing multiple independent power supplies, which then power and control multiple modules within the test system. However, using multiple power supplies complicates the test system structure, increases hardware costs, and makes it unsuitable for practical applications.

[0073] Based on the above problems, this application proposes a startup method for a converter test system. The startup method for a converter test system provided in this application can be applied to, for example... Figure 1 The converter test system shown includes a test module 110 and a support test module 120. The test system also includes a control module 140 and a power supply module 130 for connecting to an external DC voltage. The first terminal of the test module 110 is connected to the first terminal of the support test module 120, the second terminal of the support test module 120 is connected to the first terminal of the power supply module 130, and the second terminal of the power supply module 130 is connected to the second terminal of the test module 110. The third terminal of the power supply module 130 is also used to connect to an external DC voltage. The test module 110, support test module 120, and power supply module 130 are all communicatively connected to the control module 140.

[0074] When the converter test system is started, an external DC voltage source charges the power supply module 130, and the control module 140 continuously acquires the capacitor voltage of the power supply module 130. When the capacitor voltage of the power supply module 130 reaches the preset first target voltage, the control module 140 controls the power supply module 130 to output a negative voltage. Since the module under test 110 is short-circuited and conducting under negative voltage, it can be equivalent to the second terminal of the power supply module 130 being directly connected to the first terminal of the auxiliary test module 120, while the first terminal of the power supply module 130 is connected to the second terminal of the auxiliary test module 120. The negative voltage output by the power supply module 130 is directly applied to both ends of the auxiliary test module 120, charging the auxiliary test module 120.

[0075] After the auxiliary test module 120 begins charging, the control module 140 continuously acquires the capacitor voltage of the auxiliary test module 120. When the capacitor voltage of the auxiliary test module 120 reaches a preset second target voltage, the control module 140 controls the power supply module 130 to output a positive voltage. Under the positive voltage, the module under test 110 is in an uncontrolled charging state. Simultaneously, the control module 140 controls the auxiliary test module 120 to output a test voltage, which has the same polarity as the positive voltage. At this time, the series-connected power supply module 130 and auxiliary test module 120 can be regarded as a whole, jointly outputting a positive voltage to the module under test 110, thus charging the module under test 110. The control module 140 continuously acquires the capacitor voltage of the module under test 110. After detecting that the capacitor voltage of the module under test 110 has reached the preset third target voltage, it determines that the power replenishment module 130, the auxiliary test module 120 and the module under test 110 have all reached their respective rated voltages during normal operation. The converter test system starts normally and can operate stably under various test conditions (such as rated power output, transient overvoltage simulation, fault ride-through test, etc.).

[0076] In some embodiments, such as Figure 2As shown, the power supply module includes a full-bridge submodule composed of four switching transistors: Q1, Q2, Q3, and Q4. Q1 and Q3 form the left bridge arm, and Q2 and Q4 form the right bridge arm. The collectors of Q1 and Q2 are connected to the positive terminal of the DC input. The emitter of Q1 is connected to the collector and positive output terminal of Q3. The emitter of Q2 is connected to the collector and negative output terminal of Q4. The emitters of Q3 and Q4 are connected to the negative terminal of the DC input. An external DC voltage source is connected between the positive and negative terminals of the DC input. The base of each transistor is connected to an external drive signal to control the switching on and off of the transistor. A first energy storage capacitor C1 is also connected between the positive and negative terminals of the DC input terminal to store the voltage output by the DC voltage source and to supply power to other modules connected to the energy replenishment module.

[0077] When the first switch Q1 and the fourth switch Q4 are on, and the second switch Q2 and the third switch Q3 are off, the positive terminal of the DC input is connected to the positive terminal of the output through the first switch Q1, and the negative terminal of the DC input is connected to the negative terminal of the output through the fourth switch Q4, thus enabling the power supply module to output a positive voltage. When the second switch Q2 and the third switch Q3 are on, and the first switch Q1 and the fourth switch Q4 are off, the positive terminal of the DC input is connected to the negative terminal of the output through the second switch Q2, and the negative terminal of the DC input is connected to the positive terminal of the output through the third switch Q3, thus enabling the power supply module to output a reverse voltage. Therefore, the control module can control the polarity of the output voltage of the power supply module by controlling the switching states of the switches in the power supply module.

[0078] In some embodiments, the companion testing module includes multiple first half-bridge sub-modules connected in series, such as... Figure 3As shown, the first half-bridge submodule includes a fifth switch Q5, a sixth switch Q6, and a second energy storage capacitor C2. The collector of the fifth switch Q5 is connected to the first terminal of the second energy storage capacitor C2, and the emitter of the fifth switch Q5 is connected to the collector of the sixth switch Q6. When the first half-bridge submodule is connected to the positive port of the test module, the emitter of the fifth switch Q5 is also connected to the positive port of the test module, and the emitter of the sixth switch Q6 and the second terminal of the second energy storage capacitor C2 are connected to the emitter of the fifth switch Q5 in the next first half-bridge submodule. When the first half-bridge submodule is not directly connected to the positive or negative port of the test module, the emitter of the fifth switch Q5 is also connected to the emitter of the sixth switch Q6 in the previous first half-bridge submodule, and the emitter of the sixth switch Q6 and the second terminal of the second energy storage capacitor C2 are connected to the emitter of the fifth switch Q5 in the next first half-bridge submodule. With the first half-bridge submodule connected to the negative port of the auxiliary test module, the emitter of the fifth switch Q5 is also connected to the emitter of the sixth switch Q6 in the first half-bridge submodule. The emitter of the sixth switch Q6 and the second terminal of the second energy storage capacitor C2 are connected to the negative port of the auxiliary test module. The negative port of the auxiliary test module is connected to the positive output terminal of the power supply module. When the fifth switch Q5 is on and the sixth switch Q6 is off, the first half-bridge submodule is in the active state. When the fifth switch Q5 is off and the sixth switch Q6 is on, the first half-bridge submodule is bypassed.

[0079] When charging each of the first half-bridge sub-modules in the test module, the control module controls the fifth switch Q5 of the first half-bridge sub-module requiring charging to turn on and the sixth switch Q6 to turn off, switching it to the active state. The control module controls the power supply module to output a negative voltage. At this time, the module under test is short-circuited, which can be equivalent to the positive terminal of the test module being connected to the negative terminal of the power supply module. Since the voltage output by the power supply module is negative, the current flows from the negative terminal of the power supply module into the positive terminal of the test module. In the first half-bridge sub-module in the active state, after the fifth switch Q5 charges the second energy storage capacitor C2, the current flows out from the negative terminal of the test module to the positive terminal of the power supply module, thereby charging each of the first half-bridge sub-modules in the test module through the negative voltage output by the power supply module.

[0080] When the module under test needs to discharge, the control module turns on the fifth switch Q5 and turns off the sixth switch Q6 of the first half-bridge sub-module that needs to be discharged, switching it to the active state. The control module controls the power supply module to output a positive voltage. At the same time, the capacitor in the active first half-bridge module discharges. At this time, the polarity of the capacitor output voltage is the same as the polarity of the power supply module output, and together they charge the module under test.

[0081] In some embodiments, such as Figure 4As shown, the module under test includes four bridge arms 401 connected in an H-bridge topology. The upper end of the H-bridge topology is the positive port (V+ as shown in the figure), and the lower end is the negative port (V- as shown in the figure). The positive port is connected to the positive port of the auxiliary test module, and the negative port is connected to the output negative terminal of the power supply module. Each bridge arm 401 includes multiple second half-bridge sub-modules connected in series. In the two bridge arms 401 connected in series on the left or the two bridge arms 401 connected in series on the right, the lower end of the first second half-bridge sub-module is directly connected to the upper end of the second second half-bridge sub-module. The uppermost sub-module in the two bridge arms 401 connected in series is connected to the positive port, and the lowermost sub-module in the two bridge arms 401 connected in series is connected to the AC side node.

[0082] like Figure 5 As shown, the second half-bridge submodule includes diode D1, a seventh switch Q7, and a third energy storage capacitor C3. The cathode of diode D1 is connected to the anode of the third energy storage capacitor C3, and the anode of diode D1 is connected to the upper end of the second half-bridge submodule and the collector of the seventh switch Q7. The emitter of the seventh switch Q7 and the cathode of the third energy storage capacitor C3 are connected to the lower end of the second half-bridge submodule. When the seventh switch Q7 is on, the second half-bridge submodule is in a bypass state; when the seventh switch Q7 is off, the second half-bridge submodule is in a conduction state.

[0083] When the auxiliary module is being charged, and the control module controls the power supply module to output a negative voltage, the diodes in each of the seventh switching transistors Q7 form a direct path, short-circuiting and turning on the module under test, so that the power supply module can directly charge the auxiliary module.

[0084] When charging the module under test (DUT), the control module turns off the seventh switch Q7 in the second half-bridge sub-module that needs charging, switching the second half-bridge module into the active state. The control module controls the power supply module and the auxiliary test module to jointly output a positive voltage. Current flows from the positive terminal of the auxiliary test module into the positive terminal of the DUT, charges the third energy storage capacitor C3 via diode D1, and then flows from the negative terminal of the DUT into the negative terminal of the power supply module. This charges the energy storage capacitor in the second half-bridge module, which is in the active state.

[0085] In some embodiments, the control module includes a control unit and multiple secondary control loops. The control unit is connected to each secondary control loop, and each secondary control loop is connected to the module under test, the auxiliary test module, and the power replenishment module in a one-to-one correspondence. The secondary control loops are used to drive the switching state of the power devices in the connected modules, collect the capacitor voltage of the connected modules, and communicate with the control unit, so that the control unit can control the switching state of the power devices in each module according to the capacitor voltage of each module, thereby controlling the operating state of each module.

[0086] In one exemplary embodiment, such as Figure 6 As shown, a startup method for a converter test system is provided, which is applied to... Figure 1 Taking the control module 140 as an example, the explanation includes the following steps 602 to 608. Wherein:

[0087] Step 602: Obtain the capacitor voltage of the power replenishment module.

[0088] In this embodiment, the control module collects the voltage signal across the DC-side capacitor in the power replenishment module in real time through a secondary control loop in order to monitor the charging process of the power replenishment module by the external DC voltage source.

[0089] Step 604: When the capacitor voltage of the power replenishment module reaches the preset first target voltage, control the power replenishment module to output a preset negative voltage to the auxiliary test module through the module under test to charge the auxiliary test module.

[0090] The tested module is short-circuited and conducts under negative voltage; the first target voltage refers to the rated operating voltage value that the power replenishment module needs to reach.

[0091] In this embodiment, after the control module detects that the capacitor voltage of the power supply module has stabilized at the first target voltage, the control module sends a switching command to the power supply module, causing its output voltage polarity to be a preset negative voltage output. Since the module under test exhibits short-circuit conduction characteristics under this negative voltage condition, the current flows directly to the auxiliary module, charging each sub-module in the auxiliary module.

[0092] Step 606: Obtain the capacitor voltage of the test module.

[0093] In this embodiment, while the charging module outputs a negative voltage to charge the test module, the control module continuously collects the capacitor voltage of each half-bridge submodule in the test module through the secondary control loop.

[0094] Step 608: When the capacitor voltage of the auxiliary test module reaches the preset second target voltage, control the energy replenishment module to output a positive voltage to the module under test, and control the auxiliary test module to output an auxiliary voltage to the module under test. Charge the module under test with positive voltage and DC voltage until the capacitor voltage of the module under test reaches the preset third target voltage, and complete the charging start of the converter test system.

[0095] In this embodiment, after the control module confirms that the capacitor voltage of the auxiliary test module has reached the second target voltage, the control module first switches the output voltage of the charging module from negative to positive. Simultaneously, the control module causes the auxiliary test module to output its auxiliary voltage. This positive voltage and the auxiliary voltage are applied together to the module under test, performing uncontrolled charging of each energy storage capacitor within the module. During this charging process, the control module monitors the voltage of the energy storage capacitors of each sub-module within the module under test in real time, raising the voltage of all sub-modules of the module under test to the third target voltage. When the voltage of all sub-modules of the module under test reaches the third target voltage, the charging start-up process of the entire test system is completed.

[0096] The above steps utilize a single external DC voltage source to pre-charge the power supply module, bringing its capacitor voltage to the first target voltage. Subsequently, the power supply module outputs a negative voltage, which, through the internal short-circuit conduction path of the module under test (DUT), directly charges the auxiliary module without control, allowing it to obtain startup energy without an independent power supply. Once the auxiliary module's capacitor voltage reaches the second target voltage, the power supply module switches to positive voltage output, simultaneously controlling the auxiliary module to output a supplementary voltage to the DUT. The combined positive and supplementary voltages charge the DUT, ultimately bringing its capacitor voltage to the third target voltage. The entire charging process relies on only one external power supply providing the external DC voltage. By utilizing the conduction characteristics of the DUT and the voltage output capability of the auxiliary modules in stages, the power supply startup of all modules can be completed sequentially. The system structure is simple, requiring fewer external DC voltage sources. Therefore, while ensuring the converter test system starts normally and supplies power to each module, the hardware construction cost of the test system is reduced, thus improving the versatility of the test system.

[0097] In some embodiments, such as Figure 7 As shown, step 604 above includes steps 702 to 706, wherein:

[0098] Step 702: Control the charging module to output a preset negative voltage to the auxiliary module via the module under test, so as to charge the first input sub-module in the auxiliary module.

[0099] The first input submodule is the first half-bridge submodule that is in the input state.

[0100] In this embodiment, after the control module switches the output voltage of the power replenishment module to a preset negative voltage, it controls a specific number of first half-bridge sub-modules in the test module to be in the activated state. The first half-bridge sub-modules in the activated state are defined as the first activated sub-modules. The negative voltage output by the power replenishment module forms a charging circuit through the short-circuited test module. The charging current in this circuit directly acts on the energy storage capacitor of the first activated sub-modules, causing these first activated sub-modules to begin storing electrical energy, and their capacitor voltage gradually increases from zero.

[0101] Step 704: Obtain the first total capacitor voltage of the first capacitor voltage in each first input submodule.

[0102] In this embodiment, the control module continuously collects the first capacitor voltage of each first input submodule in the test module during the negative voltage charging process, and sums these first capacitor voltages to calculate the first total capacitor voltage.

[0103] Step 706: When the first total capacitor voltage reaches the preset first charging upper limit, the first preset number of first input sub-modules are bypassed.

[0104] The first charging limit corresponds to the number of units deployed in the first deployment sub-module.

[0105] In this embodiment, the control module compares the first total capacitor voltage calculated in real time with a preset first charging upper limit. This first charging upper limit is not a fixed value, but is dynamically determined based on the number of first sub-modules currently in operation. When the control module determines that the first total capacitor voltage has reached the corresponding first charging upper limit, it performs a bypass operation, disconnecting a first preset number of first sub-modules from the charging circuit, stopping the charging of these sub-modules, and redirecting the charging current in the circuit to the remaining sub-modules still in operation. In some embodiments, after starting to charge the auxiliary testing module, the control module can gradually decrease the number of first sub-modules in the auxiliary testing module at certain time intervals until the number of first sub-modules in operation is 1.

[0106] By gradually reducing the number of sub-modules put into operation, the total series voltage drop can be reduced, allowing each first sub-module to be individually or partially charged to a higher voltage, even when the output voltage of the charging module is limited.

[0107] In some embodiments, such as Figure 8 As shown, step 604 above includes steps 802 to 806, wherein:

[0108] Step 802: Obtain the first capacitor voltage of each first input submodule and the second capacitor voltage of each first bypass submodule.

[0109] The first bypass submodule is the first half-bridge submodule in the bypass state.

[0110] In this embodiment, during the charging process of the auxiliary test module, the control module continuously collects the first capacitor voltage of the first sub-module in the input state and the second capacitor voltage of the first sub-module in the bypass state within the auxiliary test module.

[0111] Step 804: The sum of the voltages of each first capacitor and each second capacitor is used as the capacitor voltage of the test module.

[0112] In this embodiment, the control module sums all the first capacitor voltages and all the second capacitor voltages collected, that is, it adds the capacitor voltages of each half-bridge submodule in the test module one by one, and the calculated sum is defined as the capacitor voltage of the test module.

[0113] Step 806: During the preset control cycle, the first input submodule with the largest first capacitor voltage is bypassed, and the first bypass submodule with the smallest second capacitor voltage is input, until the capacitor voltage of the test module reaches the preset second target voltage.

[0114] In this embodiment, the control module performs voltage equalization control operations periodically according to a preset control cycle. Within each control cycle, the control module sorts all first capacitor voltages, identifies the first connected submodule with the highest voltage value, and issues a command to bypass this submodule, stopping its charging. Simultaneously, the control module sorts all second capacitor voltages, identifies the first bypassed submodule with the lowest voltage value, and issues a command to connect this submodule, reconnecting it to the main circuit to begin charging. The control module repeatedly performs the above-mentioned cyclical operation of bypassing the high-voltage module and connecting the low-voltage module. During this process, it continuously calculates the capacitor voltage of the monitored module and compares this capacitor voltage with a second target voltage until the capacitor voltage reaches the second target voltage, at which point the voltage equalization control process stops.

[0115] By acquiring the voltage of all submodules in real time and employing a cyclic switching control strategy based on sorting and comparison, the voltage deviation between submodules can be automatically balanced during charging. This prevents some submodules from being over-voltaged while others are under-voltaged, ensuring that the voltage of all submodules rises synchronously to the second target voltage. This enables dynamic equalization adjustment of the voltage of each submodule within the test module.

[0116] In some embodiments, step 608 includes: sequentially switching each first half-bridge submodule to the active state according to a preset time interval, and outputting a test voltage to the module under test through the first half-bridge submodule in the active state.

[0117] In this embodiment, after confirming that the charging module has switched to positive voltage output, the control module begins to execute a gradual increase control of the test voltage. The control module sequentially switches one of the first half-bridge submodules in the test module from bypass to active state at a fixed time period, according to a pre-set time interval. Each time a first half-bridge submodule is switched to active state, the voltage at the output of the test module increases by an amplitude equal to the capacitor voltage of that submodule, resulting in a stepped increase in the test voltage. The control module continues this operation, gradually increasing the number of active submodules to increase the test voltage from zero. This increased test voltage is applied to the module under test, providing it with charging energy. This stepped voltage increase reduces the risk of voltage surges caused by the instantaneous activation of all submodules, thus reducing the voltage impact on the module under test.

[0118] In some embodiments, such as Figure 9 As shown, step 608 above includes steps 902 and 904, wherein:

[0119] Step 902: Charge each second input submodule in each bridge arm of the module under test with positive voltage and DC voltage.

[0120] The second input submodule is the second half-bridge submodule that is in the input state.

[0121] In this embodiment, after the test module and the power supply module output a positive voltage, the test voltage is applied between the positive and negative ports of the DC side of the module under test. The module under test contains multiple parallel bridge arms, each composed of multiple series-connected second half-bridge sub-modules. The control module controls a specific number of second half-bridge sub-modules in each bridge arm to be in the active state; these sub-modules are defined as the second active sub-modules of that bridge arm. The test voltage and the power supply module charge the capacitors of the second active sub-modules in each bridge arm, causing the capacitor voltages of these second active sub-modules to gradually increase from zero.

[0122] Step 904: For each bridge arm, obtain the second total capacitor voltage of the third capacitor voltage of each second input submodule in the bridge arm. If the second total capacitor voltage reaches the preset second charging upper limit, bypass the second preset number of second input submodules in the bridge arm.

[0123] The second charging limit corresponds to the number of second charging sub-modules deployed in the bridge arm.

[0124] In this embodiment, the control module independently performs voltage monitoring and control for each bridge arm in the tested module. For a single bridge arm, the control module collects the third capacitor voltage of each second engaged submodule within that bridge arm in real time, and sums these voltage values ​​to calculate the second total capacitor voltage of that bridge arm. The control module compares this second total capacitor voltage with a preset second charging upper limit, which is dynamically determined based on the number of second engaged submodules currently engaged in that bridge arm. When the control module determines that the second total capacitor voltage has reached the corresponding second charging upper limit, the control module performs a bypass operation within that bridge arm, disconnecting a second preset number of second engaged submodules from the charging circuit of that bridge arm, stopping these submodules from charging, while the charging current continues to charge the remaining second engaged submodules within that bridge arm.

[0125] By gradually reducing the number of sub-modules put into operation, the total series voltage drop can be reduced, allowing each first sub-module to be individually or partially charged to a higher voltage, even when the output voltage of the charging module is limited.

[0126] In some embodiments, such as Figure 10 As shown, step 608 above includes steps 1002 to 1006, wherein:

[0127] Step 1002: Obtain the third capacitor voltage of each second input submodule and the fourth capacitor voltage of each second bypass submodule.

[0128] The second bypass submodule is the second half-bridge submodule in bypass mode.

[0129] In this embodiment, during the charging process of the module under test, the control module continuously collects the third capacitor voltage of the second sub-module in the engaged state and the fourth capacitor voltage of the second sub-module in the bypass state for each bridge arm in the module under test.

[0130] Step 1004: The sum of the voltages of each third capacitor and each fourth capacitor is taken as the capacitor voltage of the module under test.

[0131] In this embodiment, the control module sums all the collected third capacitor voltages with all the fourth capacitor voltages, that is, it adds the capacitor voltages of each second half-bridge submodule in each bridge arm of the module under test one by one, and the calculated sum is the capacitor voltage of the module under test.

[0132] Step 1006: For each bridge arm, within a preset control cycle, the second input submodule with the largest third capacitor voltage in the bridge arm is bypassed, and the second bypass submodule with the smallest fourth capacitor voltage in the bridge arm is input, until the capacitor voltage of the module under test reaches the preset third target voltage.

[0133] In this embodiment, the control module independently performs voltage equalization control operations for each bridge arm of the module under test according to a preset control cycle. Within each control cycle, for a single bridge arm, the control module sorts all third capacitor voltages within that bridge arm, identifies the second connected sub-module with the highest voltage value, and issues a command to bypass this sub-module, stopping its charging. Simultaneously, the control module sorts all fourth capacitor voltages within that bridge arm, identifies the second bypass sub-module with the lowest voltage value, and issues a command to connect this sub-module, connecting it to the bridge arm circuit to begin charging. The control module independently and repeatedly performs the above-mentioned bypassing high-voltage modules and connecting low-voltage modules in each bridge arm, continuously calculating the capacitor voltage of the entire module under test during this process and comparing it with a third target voltage until the capacitor voltage of the module under test reaches the third target voltage, at which point the voltage equalization control process stops.

[0134] By acquiring the voltage of all sub-modules in real time and employing a cyclic switching control strategy based on sorting and comparison, the voltage deviation between sub-modules can be automatically balanced during charging. This prevents some sub-modules from being over-voltaged while others are under-voltaged, ensuring that the voltage of all sub-modules rises synchronously to the third target voltage. This enables dynamic equalization adjustment of the voltage of each sub-module within the module under test.

[0135] In some embodiments, such as Figure 11 As shown, after step 608 above, the start-up method of the converter test system further includes steps 1102 to 1106, wherein:

[0136] Step 1102: Obtain the fifth capacitor voltage of each first half-bridge submodule and obtain the test current flowing through the test module.

[0137] In this embodiment, after the converter test system completes charging startup and enters steady-state operation, the control module continuously collects the voltage of the fifth capacitor of each first half-bridge submodule in the auxiliary test module. Simultaneously, the control module acquires the auxiliary test current flowing through the auxiliary test module and determines in real time whether the polarity of this current is positive or negative.

[0138] Step 1104: When the test current is positive, control each first half-bridge submodule to switch to the working state in sequence according to the voltage of the fifth capacitor from small to large.

[0139] In this embodiment, the control module monitors the polarity of the test current in real time. When the test current is determined to be positive, the control module sorts the fifth capacitor voltages of all the current first half-bridge submodules, forming a sequence from lowest to highest voltage. Following this sequence, the control module prioritizes switching the first half-bridge submodule with the lowest voltage to the active state, then sequentially switches in the submodule with the second lowest voltage, and so on, ensuring that the submodule with the lowest voltage receives the longest charging time, thus allowing its voltage to be preferentially increased.

[0140] Step 1106: When the test current is negative, control each first half-bridge submodule to switch to the working state in sequence according to the voltage of the fifth capacitor from large to small.

[0141] In this embodiment, the control module monitors the polarity of the test current in real time. When the test current is determined to be negative, the control module sorts the fifth capacitor voltages of all current first half-bridge submodules, forming a sequence from highest to lowest voltage. Following this sequence, the control module prioritizes switching the first half-bridge submodule with the highest voltage to the active state, then sequentially switches the submodule with the second highest voltage to the active state, and so on, ensuring that the submodule with the highest voltage receives the longest discharge time, thus preferentially reducing its voltage.

[0142] By following the steps described above, the low-voltage sub-module is prioritized for charging during the charging half-cycle of the test module, and the high-voltage sub-module is prioritized for discharging during the discharging half-cycle. The charging and discharging process within each cycle automatically corrects the voltage deviation between the sub-modules in the test module. No additional voltage equalization circuit is required. By simply controlling the order of activation, the voltage of all sub-modules in the test module can be kept stable within the allowable range, ensuring that the test module continuously outputs a stable test voltage during steady-state operation.

[0143] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0144] Based on the same inventive concept, this application also provides a starting device for a converter test system to implement the starting method of the converter test system described above. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations in one or more starting device embodiments of the converter test system provided below can be found in the limitations of the starting method of the converter test system described above, and will not be repeated here.

[0145] In one exemplary embodiment, such as Figure 12 As shown, a start-up device for a converter test system is provided, comprising:

[0146] The first acquisition module 1201 is used to acquire the capacitor voltage of the energy replenishment module;

[0147] The first charging module 1202 is used to control the charging module to output a preset negative voltage to the auxiliary module via the module under test when the capacitor voltage of the charging module reaches the preset first target voltage, so as to charge the auxiliary module; the module under test is short-circuited and turned on under the negative voltage.

[0148] The second acquisition module 1203 is used to acquire the capacitor voltage of the test module;

[0149] The second charging module 1204 is used to control the energy replenishment module to output a positive voltage to the module under test when the capacitor voltage of the auxiliary module reaches the preset second target voltage, and to control the auxiliary module to output an auxiliary voltage to the module under test. The module under test is charged by positive voltage and DC voltage until the capacitor voltage of the module under test reaches the preset third target voltage, thus completing the charging start-up of the converter test system.

[0150] In one embodiment, the first charging module 1202 is further configured to control the charging module to output a preset negative voltage to the auxiliary testing module via the tested module, to charge the first input sub-module in the auxiliary testing module, wherein the first input sub-module is a first half-bridge sub-module in the input state; to obtain the first total capacitor voltage of the first capacitor voltage in each first input sub-module; and to bypass a first preset number of first input sub-modules when the first total capacitor voltage reaches a preset first charging upper limit, wherein the first charging upper limit corresponds to the number of first input sub-modules in the input state.

[0151] In one embodiment, the first charging module 1202 is further configured to acquire the first capacitor voltage of each first input submodule and the second capacitor voltage of each first bypass submodule, wherein the first bypass submodule is a first half-bridge submodule in a bypass state; the sum of each first capacitor voltage and each second capacitor voltage is used as the capacitor voltage of the companion module; and in a preset control cycle, the first input submodule with the largest first capacitor voltage is controlled to bypass, and the first bypass submodule with the smallest second capacitor voltage is controlled to input, until the capacitor voltage of the companion module reaches a preset second target voltage.

[0152] In one embodiment, the second charging module 1204 is further configured to sequentially switch each first half-bridge sub-module to the engaged state according to a preset time interval, and output the test voltage to the module under test through the first half-bridge module in the engaged state.

[0153] In one embodiment, the second charging module 1204 is further configured to control the auxiliary test module to output an auxiliary test voltage to the module under test, thereby charging each second input submodule in each bridge arm of the module under test, wherein the second input submodule is a second half-bridge submodule in the input state; for each bridge arm, the second total capacitor voltage of the third capacitor voltage of each second input submodule in the bridge arm is obtained; when the second total capacitor voltage reaches a preset second charging upper limit, a second preset number of second input submodules in the bridge arm are bypassed, wherein the second charging upper limit corresponds to the number of second input submodules in the bridge arm.

[0154] In one embodiment, the second charging module 1204 is further configured to acquire the third capacitor voltage of each second input submodule and the fourth capacitor voltage of each second bypass submodule, wherein the second bypass submodule is a second half-bridge submodule in a bypass state; the sum of each third capacitor voltage and each fourth capacitor voltage is used as the capacitor voltage of the module under test; for each bridge arm, in a preset control cycle, the second input submodule with the largest third capacitor voltage in the bridge arm is controlled to bypass, and the second bypass submodule with the smallest fourth capacitor voltage in the bridge arm is controlled to input, until the capacitor voltage of the module under test reaches a preset third target voltage.

[0155] In one embodiment, the starting device of the converter test system further includes an operation control module, which is used to acquire the fifth capacitor voltage of each first half-bridge sub-module and acquire the test current flowing through the test module; when the test current is positive, the first half-bridge sub-module is controlled to switch to the working state in sequence according to the fifth capacitor voltage from small to large; when the test current is negative, the first half-bridge sub-module is controlled to switch to the working state in sequence according to the fifth capacitor voltage from large to small.

[0156] Each module in the starting device of the aforementioned converter test system can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of the converter test system in hardware form or independent of it, or they can be stored in the memory of the converter test system in software form, so that the processor can call and execute the corresponding operations of each module.

[0157] In one exemplary embodiment, a converter testing system is provided, the internal structure of which can be shown in the following diagram. Figure 13 As shown, the control module of this converter test system includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor of this control module provides computational and control capabilities. The memory of this control module includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database of this control module stores the control data of the control module. The I / O interfaces of this control module are used for exchanging information between the processor and external devices. The communication interface of this control module is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a startup method for the converter test system.

[0158] Those skilled in the art will understand that Figure 13 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the control module applied thereto. The specific control module may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0159] In an exemplary embodiment, a converter testing system is provided, including a control module and a power supply module for connecting to an external DC voltage. The power supply module is also used to connect the module under test and the auxiliary test module in the converter. The module under test is also connected to the auxiliary test module. The control module is connected to the power supply module, the auxiliary test module and the module under test respectively.

[0160] The power supply module is used to connect to an external DC voltage to power the power supply module.

[0161] The control module is used to implement the steps in the above-described converter test system startup method embodiment.

[0162] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps in the above-described converter test system startup method embodiment.

[0163] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above-described converter test system startup method embodiment.

[0164] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0165] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0166] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A startup method for a converter test system, characterized in that, The converter includes a module under test (DUT) and a companion test module connected to the DUT; the converter test system includes a power supply module for connecting to an external DC voltage, the power supply module being connected to both the DUT and the companion test module; the method includes: Obtain the capacitor voltage of the power replenishment module; When the capacitor voltage of the power replenishment module reaches the preset first target voltage, the power replenishment module is controlled to output a preset negative voltage to the auxiliary test module via the module under test to charge the auxiliary test module; the module under test is short-circuited and conducts under the negative voltage. Obtain the capacitor voltage of the accompanying test module; When the capacitor voltage of the auxiliary test module reaches the preset second target voltage, the charging module is controlled to output a positive voltage to the module under test, and the auxiliary test module is controlled to output a test voltage to the module under test. The module under test is charged by the positive voltage and the DC voltage until the capacitor voltage of the module under test reaches the preset third target voltage, thus completing the charging start-up of the converter test system.

2. The method according to claim 1, characterized in that, The accompanying test module includes multiple first half-bridge sub-modules connected in series, with the first and last ends of the series connection of the multiple first half-bridge sub-modules respectively connected to the module under test and the power supply module; controlling the power supply module to output a preset negative voltage to the accompanying test module via the module under test includes: The power supply module is controlled to output a preset negative voltage to the auxiliary test module via the module under test, so as to charge the first input sub-module in the auxiliary test module. The first input sub-module is the first half-bridge sub-module in the input state. Obtain the first total capacitor voltage of the first capacitor voltage in each of the first input sub-modules; When the voltage of the first total capacitor reaches a preset first charging limit, a first preset number of the first input sub-modules are bypassed, wherein the first charging limit corresponds to the number of first input sub-modules.

3. The method according to claim 2, characterized in that, The control of the energy replenishment module to output a preset negative voltage to the auxiliary test module via the module under test includes: Obtain the first capacitor voltage of each of the first input submodules and the second capacitor voltage of each of the first bypass submodules, wherein the first bypass submodule is a first half-bridge submodule in a bypass state; The sum of the voltages of each of the first capacitors and each of the second capacitors is taken as the capacitor voltage of the test module; During the preset control cycle, the first input submodule with the largest first capacitor voltage is bypassed, and the first bypass submodule with the smallest second capacitor voltage is input, until the capacitor voltage of the accompanying test module reaches the preset second target voltage.

4. The method according to claim 1, characterized in that, The accompanying test module includes multiple first half-bridge sub-modules connected in series, with the first and last ends of the series connection of the multiple first half-bridge sub-modules respectively connected to the module under test and the power replenishment module; controlling the accompanying test module to output an accompanying test voltage to the module under test includes: According to a preset time interval, each of the first half-bridge submodules is switched to the working state in sequence, and the test voltage is output to the module under test through the first half-bridge submodule in the working state.

5. The method according to claim 1, characterized in that, The module under test includes multiple bridge arms connected according to a preset topology. The positive and negative ports of the multiple bridge arms connected according to the preset topology are respectively connected to the power supply module and the module under test. The bridge arms include multiple second half-bridge sub-modules connected in series. Charging the module under test using the positive voltage and the DC voltage includes: The positive voltage and the DC voltage are used to charge each of the second input sub-modules in each of the bridge arms of the module under test, where the second input sub-module is a second half-bridge sub-module in the input state; For each of the bridge arms, the second total capacitor voltage of the third capacitor voltage of each of the second input sub-modules in the bridge arm is obtained. When the second total capacitor voltage reaches the preset second charging upper limit, a second preset number of the second input sub-modules in the bridge arm are bypassed, wherein the second charging upper limit corresponds to the number of the second input sub-modules in the bridge arm.

6. The method according to claim 5, characterized in that, The controller charges the module under test using the positive voltage and the DC voltage, including: Obtain the third capacitor voltage of each of the second input submodules and the fourth capacitor voltage of each of the second bypass submodules, wherein the second bypass submodule is a second half-bridge submodule in a bypass state; The sum of the voltages of each of the third capacitors and the voltages of each of the fourth capacitors is taken as the capacitor voltage of the module under test; For each bridge arm, within a preset control cycle, the second input submodule with the largest third capacitor voltage in the bridge arm is bypassed, and the second bypass submodule with the smallest fourth capacitor voltage in the bridge arm is input, until the capacitor voltage of the module under test reaches the preset third target voltage.

7. The method according to claim 1, characterized in that, The test module includes multiple first half-bridge sub-modules connected in series, and the first and last ends of the multiple first half-bridge sub-modules connected in series are respectively connected to the module under test and the energy replenishment module; After the converter test system has been charged and started, the method further includes: Obtain the fifth capacitor voltage of each of the first half-bridge sub-modules, and obtain the test current flowing through the test module; When the test current is positive, each of the first half-bridge sub-modules is switched to the working state in sequence according to the fifth capacitor voltage from small to large. When the test current is negative, each of the first half-bridge submodules is switched to the working state in sequence according to the fifth capacitor voltage from large to small.

8. A starting device for a converter test system, characterized in that, The converter includes a module under test (DUT) and a companion test module connected to the DUT; the converter test system includes a power supply module for connecting to an external DC voltage, the power supply module being connected to both the DUT and the companion test module; the device includes: The first acquisition module is used to acquire the capacitor voltage of the energy replenishment module; The first charging module is used to control the charging module to output a preset negative voltage to the auxiliary testing module via the tested module when the capacitor voltage of the charging module reaches a preset first target voltage, so as to charge the auxiliary testing module; the tested module is short-circuited and conducts under the negative voltage. The second acquisition module is used to acquire the capacitor voltage of the accompanying test module; The second charging module is used to control the energy replenishment module to output a positive voltage to the module under test when the capacitor voltage of the auxiliary test module reaches a preset second target voltage, and to control the auxiliary test module to output a test voltage to the module under test. The module under test is charged by the positive voltage and the DC voltage until the capacitor voltage of the module under test reaches a preset third target voltage, thus completing the charging start-up of the converter test system.

9. A converter testing system, characterized in that, It includes a control module and a power supply module for connecting to an external DC voltage. The power supply module is also used to connect the module under test and the auxiliary test module in the converter. The module under test is also connected to the auxiliary test module. The control module is connected to the power supply module, the auxiliary test module and the module under test respectively. The power supply module is used to connect to an external DC voltage so that the power supply module is powered by the external DC voltage; The control module is used to control the charging of the energy replenishment module, the accompanying test module, and the tested module according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

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