Multi-pulse inversion control method and device

Abstract

The invention relates to the technical field of multi-pulse testing, and discloses a multi-pulse inversion control method and device, and the method comprises the steps: carrying out the short circuit of the AC side of an inverter, matching with a simple tool, completing the building of a test loop, and not needing to frequently change the wiring mode or adjust the position of a pair tube for a single to-be-tested switch tube. The test operation process is greatly simplified, and the problems of tedious wiring and long consumed time of the existing multi-pulse test are solved; the magnetizing loop and the follow current loop are accurately constructed and alternately run, the inductive current can stably rise to a preset threshold value, key waveform data such as voltage stress, current stress, driving and reverse recovery can be accurately collected in the process, the working characteristics of a switching tube in a system loop are comprehensively verified, and the running reliability of an inverter is effectively guaranteed.

Description

Technical Field

[0001] This invention relates to the field of multi-pulse testing technology, and specifically to a multi-pulse inverter control method and device. Background Technology

[0002] In the field of photovoltaic energy storage inverter system technology, transistor stress testing and verification of photovoltaic grid-connected inverters and energy storage inverters is a key link in ensuring product reliability. Currently, the industry mainly uses multi-pulse test verification platforms to meet this testing requirement. For T-Type Neutral Point Clamped (TNPC) topology, existing multi-pulse test solutions require testing each transistor under test individually. During the testing process, not only are transistors under test frequently replaced, but the pairing positions of the transistors under test also need to be adjusted accordingly to adapt to the test requirements, making the entire testing and wiring operation process cumbersome, time-consuming, and labor-intensive.

[0003] At the same time, refer to Figure 1 The existing multi-pulse test platform, as shown, has a highly complex multi-pulse debugging process. It requires continuous optimization of the time parameters T1, T2, and T3 during testing, based on the different characteristics of the transistors under test. This not only increases the debugging difficulty but also significantly limits the system's hardware modification, scalability, and flexibility. Furthermore, existing multi-pulse test platforms can only perform independent testing of a single transistor, failing to meet the universality requirements of inverter transistor verification and struggling to adapt to the batch testing needs of mass production scenarios. These problems directly lead to the inability of existing testing solutions to guarantee the consistency of photovoltaic grid-connected inverters and energy storage inverters. They also have significant shortcomings in terms of universality for mass production and product reliability, failing to meet the industry's demand for efficient, accurate, and mass-production-compatible transistor stress testing. Summary of the Invention

[0004] This invention provides a multi-pulse inverter control method and apparatus to solve the problem in the prior art that when performing pulse testing on inverter switching transistors, it is necessary to frequently change the wiring method or adjust the position of the transistors for a single transistor under test, which leads to a complicated testing process and makes it impossible to perform batch testing of switching transistors.

[0005] In a first aspect, the present invention provides a multi-pulse inverter control method. This method is applied to multi-pulse testing of a TNPC inverter, where the DC side of the inverter is connected to DC power and the AC side is short-circuited. When performing a full-machine multi-pulse test on any bridge arm switch of any phase, the control method includes: using the bridge arm switch as the target switch; constructing a magnetization circuit using the bridge arm switch of the target phase and the opposing bridge arm switches of the other two phases; constructing a freewheeling circuit using the freewheeling switch of the target phase and the freewheeling switches of the other two phases; and alternately constructing the magnetization circuit... The magnetic circuit and freewheeling circuit are blocked when the test conditions are met, and the characteristic parameters of the target switch are tested and recorded. When performing a pulse test on any freewheeling switch of any phase, the control method includes: taking the freewheeling switch as the target switch; constructing a magnetization circuit through the freewheeling switch of the phase and the bridge arm switches of the other two phases; constructing a freewheeling circuit through the freewheeling switch of the phase and the freewheeling switches of the other two phases; alternately constructing the magnetization circuit and the freewheeling circuit, blocking the wave when the test conditions are met, and testing and recording the characteristic parameters of the target switch.

[0006] In one optional implementation, when performing a multi-pulse test on the upper arm switch of any phase, this phase is taken as the target phase, and the upper arm switch is taken as the target switch. The process of constructing the magnetization circuit and the freewheeling circuit includes: controlling the first freewheeling switch of the target phase to be continuously turned on and the lower arm switch to be continuously turned off; controlling the upper arm switch and the second freewheeling switch of the target phase to be alternately turned on and off; controlling the upper arm switch and the lower arm switch of the other two phases to be continuously turned off, and controlling the first freewheeling switch and the second freewheeling switch of the other two phases to be continuously turned on; wherein, when the upper arm switch of the target phase is turned on and the second freewheeling switch is turned off, the magnetization circuit is formed by the upper arm switch of the target phase and the first freewheeling switch and the second freewheeling switch of the other two phases; when the upper arm switch of the target phase is turned off and the second freewheeling switch is turned on, the freewheeling circuit is formed by the first freewheeling switch and the second freewheeling switch of each phase.

[0007] In one optional implementation, when performing a multi-pulse test on the first freewheeling switch of any phase, the phase is taken as the target phase and the first freewheeling switch is taken as the target switch. The process of constructing the magnetization circuit and the freewheeling circuit includes: controlling the upper and lower bridge arm switches of the target phase to be continuously off, and controlling the first and second freewheeling switches of the target phase to be continuously on; controlling the upper bridge arm switches of the other two phases to be continuously off and the second freewheeling switches to be continuously on, and controlling the first freewheeling switches and the lower bridge arm switches of the other two phases to be alternately on and off; wherein, when the first freewheeling switches of the other two phases are off and the lower bridge arm switches are on, the magnetization circuit is formed by the first freewheeling switch of the target phase, the second freewheeling switch of the target phase, and the lower bridge arm switches of the other two phases; when the first freewheeling switches of the other two phases are on and the lower bridge arm switches are off, the freewheeling circuit is formed by the first and second freewheeling switches of each phase.

[0008] In one optional implementation, when performing a multi-pulse test on the second freewheeling switch of any phase, the phase is taken as the target phase and the second freewheeling switch is taken as the target switch. The process of constructing the magnetization circuit and the freewheeling circuit includes: controlling the upper and lower bridge arm switches of the target phase to be continuously turned off, and controlling the first and second freewheeling switches of the target phase to be continuously turned on; controlling the lower bridge arm switches of the other two phases to be continuously turned off and the first freewheeling switches to be continuously turned on, and controlling the second freewheeling switches and the upper bridge arm switches of the other two phases to be alternately turned on and off; wherein, when the upper bridge arm switches of the other two phases are turned on and the second freewheeling switches are turned off, the magnetization circuit is formed by the first freewheeling switch of the target phase, the second freewheeling switch of the target phase, and the upper bridge arm switches of the other two phases; when the upper bridge arm switches of the other two phases are turned off and the second freewheeling switches are turned on, the freewheeling circuit is formed by the first and second freewheeling switches of each phase.

[0009] In one optional implementation, when performing a multi-pulse test on the lower bridge arm switch of any phase, this phase is taken as the target phase, and the lower bridge arm switch is taken as the target switch. The process of constructing the magnetization circuit and the freewheeling circuit includes: controlling the second freewheeling switch of the target phase to be continuously turned on and the upper bridge arm switch to be continuously turned off; controlling the lower bridge arm switch of the target phase and the first freewheeling switch of the target phase to be alternately turned on and off; controlling the upper bridge arm switch and the lower bridge arm switch of the other two phases to be continuously turned off, and controlling the first freewheeling switch and the second freewheeling switch of the other two phases to be continuously turned on; wherein, when the lower bridge arm switch of the target phase is turned on and the first freewheeling switch is turned off, the magnetization circuit is formed by the lower bridge arm switch of the target phase and the first freewheeling switch and the second freewheeling switch of the other two phases; when the lower bridge arm switch of the target phase is turned off and the first freewheeling switch is turned on, the freewheeling circuit is formed by the first freewheeling switch and the second freewheeling switch of each phase.

[0010] In one alternative implementation, the process of blocking the waveform when the test conditions are met includes: triggering the waveform blocking action of all transistors when the inductor current of the inverter reaches a preset current threshold.

[0011] In one optional implementation, the multi-pulse test process includes: obtaining a complete test pulse by alternately constructing a magnetizing circuit and a freewheeling circuit within one pulse cycle; repeatedly and alternately executing the process of "obtaining a complete test pulse by alternately constructing a magnetizing circuit and a freewheeling circuit within one pulse cycle" by controlling the inverter transistor drive timing to obtain multiple consecutive test pulses; and monitoring the change of inverter inductor current in real time during the cycle of multiple consecutive pulse cycles until the current value rises to a preset overcurrent protection threshold.

[0012] Secondly, the present invention provides a multi-pulse inverter control device. Based on the above-mentioned multi-pulse inverter control method, the device includes: a first test module, used for performing a whole-machine multi-pulse test on any bridge arm switch of any phase, wherein the control method includes: taking the bridge arm switch as the target switch; constructing a magnetization circuit through the bridge arm switch of the phase and the opposing bridge arm switches of the other two phases; constructing a freewheeling circuit through the freewheeling switch of the phase and the freewheeling switches of the other two phases; alternately constructing the magnetization circuit and the freewheeling circuit, and blocking the pulse when the test conditions are met, testing and recording the characteristic parameters of the target switch; a second test module, used for performing a pulse test on any freewheeling switch of any phase, wherein the control method includes: taking the freewheeling switch as the target switch; constructing a magnetization circuit through the freewheeling switch of the phase and the bridge arm switches of the other two phases; constructing a freewheeling circuit through the freewheeling switch of the phase and the freewheeling switches of the other two phases; alternately constructing the magnetization circuit and the freewheeling circuit, and blocking the pulse when the test conditions are met, testing and recording the characteristic parameters of the target switch;

[0013] Thirdly, the present invention provides an electronic device, comprising: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the multi-pulse inverter control method described in the first aspect or any corresponding embodiment thereof.

[0014] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to execute the multi-pulse inverter control method described in the first aspect or any corresponding embodiment thereof.

[0015] Fifthly, the present invention provides a computer program product, including computer instructions, which are used to cause a computer to execute the multi-pulse inverter control method described in the first aspect or any corresponding embodiment thereof.

[0016] Beneficial effects: The multi-pulse inverter control method provided by this invention, when applied to multi-pulse testing of TNPC inverters, has significant technical advantages and practical value: It simplifies the testing process by allowing for easy setup of the test circuit through short-circuiting the AC side of the inverter and using simple fixtures. This eliminates the need for frequent changes in wiring or adjustments to the positions of individual transistors under test, greatly simplifying the testing procedure and solving the problems of cumbersome wiring and time-consuming processes in existing multi-pulse testing. Furthermore, by precisely constructing and alternating the magnetization and freewheeling circuits, the inductor current can be stably increased to a preset threshold. During this process, voltage stress, current stress, and drive current can be accurately collected. The method comprehensively verifies the operating characteristics of the switching transistors in the system circuit by analyzing key waveform data such as dynamic and reverse recovery, effectively ensuring the reliability of inverter operation. This method is compatible with the testing requirements of bridge arm switching transistors and freewheeling switching transistors in TNPC three-level topology, eliminating the need for repeated optimization and debugging parameters for switching transistors with different characteristics. The system has greater scalability and flexibility, and can be directly imported into the production testing stage to meet the universal testing requirements in mass production scenarios. This significantly improves the consistency and universality of photovoltaic energy storage inverters in the mass production process, and comprehensively overcomes the shortcomings of existing technologies in terms of testing efficiency, universality, and mass production adaptability. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 It is a multi-pulse testing platform based on existing technology; Figure 2 It is a TNPC topology diagram; Figure 3(a) is a flowchart of a multi-pulse inverter control method for bridge arm switching transistors according to an embodiment of the present invention; Figure 3(b) is a flowchart of a multi-pulse inverter control method for a freewheeling switch according to an embodiment of the present invention; Figure 4 This is a test of phase A according to an embodiment of the present invention. Q a1 Magnetizing circuit when conduction is enabled; Figure 5 This is a test of phase A according to an embodiment of the present invention. Q a1 When the freewheeling loop is closed; Figure 6 It is phase A according to an embodiment of the present invention. Q a1 Waveforms of the drive wave and inductor current; Figure 7 This is a test of phase A according to an embodiment of the present invention. Q a2 Magnetizing circuit when conduction is enabled; Figure 8 This is a test of phase A according to an embodiment of the present invention. Q a2 When the freewheeling loop is closed; Figure 9 It is phase A according to an embodiment of the present invention. Q a2 Waveforms of the drive wave and inductor current; Figure 10 This is a test of phase A according to an embodiment of the present invention. Q a3 Magnetizing circuit when conduction is enabled; Figure 11 This is a test of phase A according to an embodiment of the present invention. Q a3 When the freewheeling loop is closed; Figure 12 It is phase A according to an embodiment of the present invention. Q a3 Waveforms of the drive wave and inductor current; Figure 13 This is a test of phase A according to an embodiment of the present invention. Q a4 Magnetizing circuit when conduction is enabled; Figure 14 This is a test of phase A according to an embodiment of the present invention. Q a4 When the freewheeling loop is closed; Figure 15 It is phase A according to an embodiment of the present invention.Q a4 Waveforms of the drive wave and inductor current; Figure 16 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] It is understood that before using the technical solutions disclosed in the various embodiments of the present invention, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in the present invention and their authorization should be obtained in accordance with relevant laws and regulations through appropriate means.

[0021] According to an embodiment of the present invention, a multi-pulse inverter control method embodiment is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0022] This embodiment provides a multi-pulse inverter control method, which is applied to... Figure 2 The TNPC inverter shown is subjected to a multi-pulse test. The DC side of the inverter is connected to DC power, and the AC side of the inverter is short-circuited.

[0023] Specifically, refer to Figure 2 Each phase of the TNPC inverter includes: upper arm switching transistor ( Q a1 , Q b1 , Q c1 ), lower bridge arm switch tube ( Q a4 , Q b4 , Q c4 ), first freewheeling switch ( Q a2 , Q b2 , Q c2 ), second freewheeling switch ( Q a3, Q b3 , Q c3 In this configuration, each switching transistor is either an IGBT or a MOSFET. Taking an IGBT as an example, its components include: 1. The IGBT itself, which controls the switching on and off, is marked with a transistor symbol; 2. The anti-parallel diodes of the main IGBT, such as diode symbols.

[0024] This embodiment only short-circuits the three phases L1, L2, and L3 of the output AC circuit. The short-circuiting fixture is simple. By controlling the inverter transistor drive timing, under multiple consecutive duty cycles, the current of the transistor under test and the inductor of the phase under test reaches the overcurrent protection value, thus obtaining the corresponding test waveform. Under this control method, the verification platform wiring is simple. Testing the bridge arm switches and freewheeling switches of the TNPC three-level topology does not require frequent changes to the inductor wiring for the switches under test. Furthermore, the test platform can be switched via AC-side relays, allowing the entire unit to be imported into production testing with multi-pulse capability. This provides mass production applicability and can effectively improve the reliability of photovoltaic grid-connected inverters or energy storage inverters.

[0025] Based on this, after short-circuiting the AC side of the inverter, when performing a multi-pulse test on any bridge arm switch of any phase, as shown in Figure 3(a), the multi-pulse inverter control includes the following steps: Step S11: Use the bridge arm switch transistor as the target switch transistor; Step S12: The magnetization circuit is constructed by the bridge arm switch of this phase and the opposing bridge arm switches of the other two phases; the freewheeling circuit is constructed by the freewheeling switch of this phase and the freewheeling switch of the other two phases. Step S13: Alternately construct the magnetization circuit and the freewheeling circuit. When the test conditions are met, block the wave and test and record the characteristic parameters of the target switching transistor.

[0026] When performing a pulse test on any freewheeling switch in any phase, as shown in Figure 3(b), the control method includes: Step S21: Use the freewheeling switch as the target switch; Step S22: The magnetization circuit is constructed by the freewheeling switch of this phase and the bridge arm switches of the other two phases; the freewheeling circuit is constructed by the freewheeling switch of this phase and the freewheeling switches of the other two phases. Step S23: Alternately construct the magnetization circuit and the freewheeling circuit. When the test conditions are met, block the wave and test and record the characteristic parameters of the target switching transistor.

[0027] Specifically, based on the circuit design logic of the whole machine multi-pulse test, the bridge arm switch of the target test phase is used in conjunction with the opposing bridge arm switches of the other two phases to form a complete magnetization path. The DC bus power supply flows through the power inductor of the target phase through this path, causing the inverter inductor current to rise rapidly and continuously during the circuit conduction period.

[0028] After the magnetization circuit is completed, a freewheeling path is constructed using the freewheeling switch of the target test phase and the freewheeling switches of the other two phases. Utilizing the physical characteristic that the direction of inductor current cannot change abruptly, the current flows smoothly through this freewheeling path, avoiding impact damage to the device caused by sudden current changes and ensuring the safety and stability of the testing process.

[0029] Optionally, the multi-pulse test process includes: obtaining a complete test pulse by alternately constructing a magnetizing circuit and a freewheeling circuit within one pulse cycle; repeatedly and alternately executing the process of "obtaining a complete test pulse by alternately constructing a magnetizing circuit and a freewheeling circuit within one pulse cycle" by controlling the inverter transistor drive timing to obtain multiple consecutive test pulses; and monitoring the change of inverter inductor current in real time during the cycle of multiple consecutive pulse cycles until the current value rises to a preset overcurrent protection threshold.

[0030] The magnetization and freewheeling processes in steps S12 and S22 constitute a complete switching cycle pulse. By precisely controlling the inverter transistor drive timing, the magnetization circuit construction and freewheeling circuit construction operations are repeatedly and alternately executed. During the continuous cycle of multiple pulse cycles, the inverter inductor current change is monitored in real time until the current value rises to the preset overcurrent protection threshold. At this time, the inverter automatically triggers the waveform blocking action of all transistors. The test system synchronously collects and records key parameters such as the target switch current Ic, the target switch voltage Vce, and the drive waveform and reverse recovery waveform during this process, completing the multi-pulse test of the current target switch and providing complete data support for evaluating the voltage stress, current stress, and operational reliability of the transistor.

[0031] In one optional implementation, when performing a multi-pulse test on the upper arm switch of any phase, this phase is taken as the target phase, and the upper arm switch is taken as the target switch. The process of constructing the magnetization circuit and the freewheeling circuit includes: controlling the first freewheeling switch of the target phase to be continuously turned on and the lower arm switch to be continuously turned off; controlling the upper arm switch and the second freewheeling switch of the target phase to be alternately turned on and off; controlling the upper arm switch and the lower arm switch of the other two phases to be continuously turned off, and controlling the first freewheeling switch and the second freewheeling switch of the other two phases to be continuously turned on; wherein, when the upper arm switch of the target phase is turned on and the second freewheeling switch is turned off, the magnetization circuit is formed by the upper arm switch of the target phase and the first freewheeling switch and the second freewheeling switch of the other two phases; when the upper arm switch of the target phase is turned off and the second freewheeling switch is turned on, the freewheeling circuit is formed by the first freewheeling switch and the second freewheeling switch of each phase.

[0032] Specifically, based on the above method, the control methods for each switch of the inverter are shown in Tables 1 to 3. Table 1 shows the control methods for the upper bridge arm switch of phase A. Q a1 Multi-pulse testing, Table 2 shows the results for the B-phase upper arm switch transistor. Q b1 Multi-pulse testing, Table 3 shows the results for the C-phase upper arm switch transistor. Q c1 Multi-pulse test.

[0033] Table 1

[0034] Table 2

[0035] Table 3

[0036] in, Q x1 Corresponding to phases A, B, and C Q a1 , Q b1 , Q c1 (Q) x1 -Q x4 Similarly, DUTY represents the duty cycle, where "0" indicates normally closed and "1" indicates normally closed.

[0037] For phase A Q a1 Taking multi-pulse testing as an example, in Table 1, DUTY is... Q a1 duty cycle, Qa1 and Q a3 Complementary conduction (complementary conduction is...) Q a3 The duty cycle is 1-DUTY).

[0038] Figure 4 Phase A Q a1 When the magnetization circuit is turned on, during its duty cycle DUTY (DUTY is set as a percentage of the switching cycle, such as 20%, 30%, 40%, etc.), the DC power supply of the busbar passes through phase A. Q a1 IGBTs and power inductors of phase A L a1 To the AC side, and then through phase B respectively Q b3 The IGBT body of the tube and Q b2 The anti-parallel diode of the tube, the C-phase Q c3 The IGBT body of the tube and Q c2 The anti-parallel diodes of the tube form a charging circuit through the upper BUS capacitor, and the inverter inductor current rises rapidly when it is turned on.

[0039] Figure 5 Phase A Q a1 When the freewheeling circuit is shut down, at the time its duty cycle DUTY is off, phase A's... Q a3 Complementary conduction (Phase A second freewheeling tube) Q a3 The duty cycle is 1-DUTY. Since the direction of the inductor current cannot change abruptly, the freewheeling current flows through the power inductor of phase A. L a1 To the AC side, and then through phase B respectively Q b3 The IGBT body of the tube and Q b2 The anti-parallel diode of the tube, the C-phase Q c3 The IGBT body of the tube and Q c2 The anti-parallel diode of the tube, through phase A Q a2 The IGBT body of the tube and Q a3 The anti-parallel diodes form a circuit, and the inverter inductor current freewheels.

[0040] The above-described charging and freewheeling cycles constitute one switching pulse, such as... Figure 6 As shown, after multiple switching cycle pulses, the inverter's output inductor current continuously rises until it reaches the overcurrent protection point. When the current protection point is reached, all transistors in the inverter are blocked, allowing for detailed testing and verification of the current Ic, voltage Vce, and drive and reverse recovery waveforms. This embodiment uses multiple pulse tests on the entire unit, which has a significant advantage: it allows for real-time adjustment of the duty cycle and the actual number of pulses, enabling observation of transistor stress and drive waveforms under multiple different turn-off currents.

[0041] In one optional implementation, when performing a multi-pulse test on the first freewheeling switch of any phase, the phase is taken as the target phase and the first freewheeling switch is taken as the target switch. The process of constructing the magnetization circuit and the freewheeling circuit includes: controlling the upper and lower bridge arm switches of the target phase to be continuously off, and controlling the first and second freewheeling switches of the target phase to be continuously on; controlling the upper bridge arm switches of the other two phases to be continuously off and the second freewheeling switches to be continuously on, and controlling the first freewheeling switches and the lower bridge arm switches of the other two phases to be alternately on and off; wherein, when the first freewheeling switches of the other two phases are off and the lower bridge arm switches are on, the magnetization circuit is formed by the first freewheeling switch of the target phase, the second freewheeling switch of the target phase, and the lower bridge arm switches of the other two phases; when the first freewheeling switches of the other two phases are on and the lower bridge arm switches are off, the freewheeling circuit is formed by the first and second freewheeling switches of each phase.

[0042] Specifically, based on the above method, the control methods for each switch of the inverter are shown in Tables 4 to 6. Table 4 shows the control methods for the first freewheeling switch of phase A. Q a2 Multi-pulse testing, Table 5 shows the results for the first freewheeling switch of phase B. Q b2 Multi-pulse testing, Table 6 shows the results for the first freewheeling switch in phase C. Q c2 Multi-pulse test.

[0043] Table 4

[0044] Table 5

[0045] Table 6

[0046] in, Q x2 Corresponding to phases A, B, and C Q a2 , Q b2 ,Q c2 ( Q x1 - Q x4 Similarly, DUTY represents the duty cycle, where "0" indicates normally closed and "1" indicates normally closed.

[0047] For phase A Q a2 Taking multi-pulse testing as an example, in Table 4, DUTY represents phase B and phase C. Q b , Q c4 duty cycle, Q b2 and Q b4 Complementary conduction, Q c2 and Q c4 Complementary conduction (i.e.) Q b2 , Q c2 The duty cycle is 1-DUTY).

[0048] Figure 7 Phase A Q a2 Conduction, phase B and phase C Q b4 and Q c4 When the magnetization circuit is turned on, during its duty cycle DUTY (DUTY is set as a percentage of the switching cycle, such as 20%, 30%, 40%, etc.), the DC power supply to the bus passes through phase A. Q a2 The IGBT body and its anti-parallel diode, and the power inductor of phase A. L a1 To the AC side, then through phase B and phase C respectively. Q b4 and Q c4 The IGBT forms a charging circuit through the lower BUS capacitor, and the inductor current rises rapidly when it is turned on.

[0049] Figure 8 Phase A Q a2 Conduction, phase B and phase C Q b4 and Q c4 When the freewheeling circuit is shut down, at its duty cycle DUTY, at this time... Q b2 andQ b4 Complementary conduction, Q c2 and Q c4 Complementary conduction (complementary conduction means phase B and phase C) Q b2 , Q c2 The duty cycle is 1-DUTY. Since the direction of the inductor current cannot change abruptly, the freewheeling current flows through the power inductor of phase A. L a1 To the AC side, and then through phase B respectively Q b3 The IGBT body of the tube and Q b2 The anti-parallel diode of the tube, the C-phase Q c3 The IGBT body of the tube and Q c2 The anti-parallel diode of the tube, through phase A Q a2 IGBT body and Q a3 The anti-parallel diodes form a circuit, and the inductor current freewheels.

[0050] The above-described charging and freewheeling cycles constitute one switching pulse, such as... Figure 9 As shown, after multiple switching cycle pulses, the inverter's output inductor current continuously rises until it reaches the overcurrent protection point. When the current protection point is reached, all transistors in the inverter are blocked, allowing for detailed testing and verification of the current Ic, voltage Vce, and drive and reverse recovery waveforms. This invention uses multiple pulse tests on the entire unit, offering significant advantages such as real-time adjustment of the duty cycle and the actual number of pulses, enabling observation of transistor stress and drive waveforms under various turn-off currents.

[0051] In one optional implementation, when performing a multi-pulse test on the second freewheeling switch of any phase, the phase is taken as the target phase and the second freewheeling switch is taken as the target switch. The process of constructing the magnetization circuit and the freewheeling circuit includes: controlling the upper and lower bridge arm switches of the target phase to be continuously turned off, and controlling the first and second freewheeling switches of the target phase to be continuously turned on; controlling the lower bridge arm switches of the other two phases to be continuously turned off and the first freewheeling switches to be continuously turned on, and controlling the second freewheeling switches and the upper bridge arm switches of the other two phases to be alternately turned on and off; wherein, when the upper bridge arm switches of the other two phases are turned on and the second freewheeling switches are turned off, the magnetization circuit is formed by the first freewheeling switch of the target phase, the second freewheeling switch of the target phase, and the upper bridge arm switches of the other two phases; when the upper bridge arm switches of the other two phases are turned off and the second freewheeling switches are turned on, the freewheeling circuit is formed by the first and second freewheeling switches of each phase.

[0052] Specifically, based on the above method, the control methods for each switch of the inverter are shown in Tables 7 to 9. Table 7 shows the control methods for the second freewheeling switch of phase A. Q a3 Multi-pulse testing, Table 8 shows the results for the second freewheeling switch of phase B. Q b3 Multi-pulse testing, Table 9 shows the results for the second freewheeling switch in phase C. Q c3 Multi-pulse test.

[0053] Table 7

[0054] Table 8

[0055] Table 9

[0056] in, Q x3 Corresponding to phases A, B, and C Q a3 , Q b3 , Q c3 ( Q x1 - Q x4 Similarly, DUTY represents the duty cycle, where "0" indicates normally closed and "1" indicates normally closed.

[0057] For phase A Q a3 Taking multi-pulse testing as an example, in Table 7, DUTY represents phase B and phase C.Q b1 , Q c1 duty cycle, Q b1 and Q b3 Complementary conduction, Q c1 and Q c3 Complementary conduction (i.e.) Q b3 , Q c3 The duty cycle is 1-DUTY).

[0058] test Q x3 Magnetization circuit and testing Q x2 The magnetization circuits differ, and are generally different in the overall circuitry. Q x1 pipe and Q x3 The tubes are complementary conductors. Q x2 pipe and Q x4 The transistors are complementary conductors. (Test) Q a2 The magnetization circuit is through phase B. Q b4 and C phase Q c4 Magnetization completed; testing Q a3 The magnetization circuit is through phase B. Q b1 and C phase Q c1 Magnetization is complete.

[0059] Figure 10 Phase A Q a3 On, phase B Q b1 and C phase Q c1 When the magnetization circuit is turned on, during its duty cycle DUTY (DUTY is set as a percentage of the switching cycle, such as 20%, 30%, 40%, etc.), the DC power supply to the bus passes through phase B. Q b1 and C phase Q c1 IGBTs and power inductors of phase A L a1 To the AC side, then through phase A Qa3 IGBT body and Q a2 The anti-parallel diodes form a charging circuit through the upper BUS capacitor, and the inductor current rises rapidly when the circuit is turned on.

[0060] Figure 11 Phase A Q a3 On, phase B Q b1 and C phase Q c1 When the freewheeling circuit is shut down, at the time its duty cycle DUTY is off, phase B's current is... Q b3 and Q b1 Complementary conduction, C phase Q c3 and Q c1 Complementary conduction (i.e.) Q b3 , Q c3 The duty cycle is 1-DUTY. Since the direction of the inductor current cannot change abruptly, the freewheeling current passes through phase B. Q b2 The IGBT body of the tube and Q b3 The anti-parallel diode of the tube, the C-phase Q c2 The IGBT body of the tube and Q c3 The anti-parallel diode of the tube flows through the power inductor of phase A. L a1 To the AC side, then through phase A Q a3 The IGBT body of the tube and Q a2 The anti-parallel diodes form a circuit, and the inductor current freewheels.

[0061] The above-described charging and freewheeling cycles constitute one switching pulse, such as... Figure 12 As shown, after multiple switching cycle pulses, the inverter's output inductor current continuously rises until it reaches the overcurrent protection point. When the current protection point is reached, all transistors in the inverter are blocked, allowing for detailed testing and verification of the collector current Ic, voltage Vce, and drive and reverse recovery waveforms. This invention uses multiple pulse tests on the entire unit, offering significant advantages such as real-time adjustment of the duty cycle and the actual number of pulses, enabling observation of transistor stress and drive waveforms under various turn-off currents.

[0062] In one optional implementation, when performing a multi-pulse test on the lower bridge arm switch of any phase, this phase is taken as the target phase, and the lower bridge arm switch is taken as the target switch. The process of constructing the magnetization circuit and the freewheeling circuit includes: controlling the second freewheeling switch of the target phase to be continuously turned on and the upper bridge arm switch to be continuously turned off; controlling the lower bridge arm switch of the target phase and the first freewheeling switch of the target phase to be alternately turned on and off; controlling the upper bridge arm switch and the lower bridge arm switch of the other two phases to be continuously turned off, and controlling the first freewheeling switch and the second freewheeling switch of the other two phases to be continuously turned on; wherein, when the lower bridge arm switch of the target phase is turned on and the first freewheeling switch is turned off, the magnetization circuit is formed by the lower bridge arm switch of the target phase and the first freewheeling switch and the second freewheeling switch of the other two phases; when the lower bridge arm switch of the target phase is turned off and the first freewheeling switch is turned on, the freewheeling circuit is formed by the first freewheeling switch and the second freewheeling switch of each phase.

[0063] Specifically, based on the above method, the control methods for each switch of the inverter are shown in Tables 10 to 12. Table 10 shows the control methods for the lower bridge arm switch of phase A. Q a4 Multi-pulse testing, Table 11 shows the results for the B-phase lower arm switch transistor. Q b4 Multi-pulse testing, Table 12 shows the results for the C-phase lower arm switch transistor. Q c4 Multi-pulse test.

[0064] Table 10

[0065] Table 11

[0066] Table 12

[0067] in, Q x4 Corresponding to phases A, B, and C Q a4 , Q b4 , Q c4 ( Q x1 - Q x4 Similarly, DUTY represents the duty cycle, where "0" indicates normally closed and "1" indicates normally closed.

[0068] For phase A Q a3 Taking multi-pulse testing as an example, in Table 10, DUTY represents phase A. Qa4 Duty cycle, Phase A Q a2 and Q a4 Complementary conduction (i.e.) Q a2 The duty cycle is 1-DUTY).

[0069] Figure 13 Phase A Q a4 When the magnetization circuit is turned on, during its duty cycle DUTY (DUTY is set as a percentage of the switching cycle, such as 20%, 30%, 40%, etc.), the DC power supply of the busbar passes through phase A. Q a4 The IGBT, after passing through the lower half of the BUS capacitor, then through the B phase... Q b2 The IGBT body of the tube and Q b3 The anti-parallel diode of the tube, the C-phase Q c2 The IGBT body of the tube and Q c3 The anti-parallel diodes of the tube form a circuit, and the inverter inductor current rises rapidly when it is turned on.

[0070] Figure 14 Phase A Q a4 When the freewheeling circuit is shut down, at the time its duty cycle DUTY is off, phase A's... Q a2 Complementary conduction (phase A) Q a2 The duty cycle is 1-DUTY. Since the direction of the inductor current cannot change abruptly, the freewheeling current flows through the power inductor of phase A. L a1 Phase A Q a3 The IGBT body of the tube and Q a2 The anti-parallel diodes of the tube form a circuit, which is then passed through phase B respectively. Q b2 The IGBT body of the tube and Q b3 The anti-parallel diode of the tube, the C-phase Q c2 The IGBT body of the tube and Q c3 The anti-parallel diodes form a circuit, and the inverter inductor current freewheels.

[0071] The above-described charging and freewheeling cycles constitute one switching pulse, such as... Figure 15As shown, after multiple switching cycle pulses, the inverter's output inductor current continuously rises until it reaches the overcurrent protection point. When the current protection point is reached, all transistors in the inverter are blocked, allowing for detailed testing and verification of the current Ic, voltage Vce, and drive and reverse recovery waveforms. This invention uses multiple pulse tests on the entire unit, offering significant advantages such as real-time adjustment of the duty cycle and the actual number of pulses, enabling observation of transistor stress and drive waveforms under various turn-off currents.

[0072] This embodiment also provides a multi-pulse inverter control device for implementing the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0073] This embodiment provides a multi-pulse inverter control device. Based on the above multi-pulse inverter control method, the device includes: The first test module is used to perform a multi-pulse test on any bridge arm switch of any phase. The control method includes: taking the bridge arm switch as the target switch; constructing a magnetization circuit through the bridge arm switch of the phase and the opposing bridge arm switches of the other two phases; constructing a freewheeling circuit through the freewheeling switch of the phase and the freewheeling switches of the other two phases; alternately constructing the magnetization circuit and the freewheeling circuit; blocking the wave when the test conditions are met; testing and recording the characteristic parameters of the target switch. The second test module is used to perform pulse testing on any freewheeling switch in any phase. The control method includes: taking the freewheeling switch as the target switch; constructing a magnetization circuit through the freewheeling switch of the phase and the bridge arm switches of the other two phases; constructing a freewheeling circuit through the freewheeling switch of the phase and the freewheeling switches of the other two phases; alternately constructing the magnetization circuit and the freewheeling circuit; blocking the wave when the test conditions are met; testing and recording the characteristic parameters of the target switch.

[0074] The multi-pulse inverter control device provided in this embodiment of the invention can execute the multi-pulse inverter control method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects for executing the method. Further functional descriptions of the various modules and units described above are the same as in the corresponding embodiments described above, and will not be repeated here.

[0075] Figure 16 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention.

[0076] The following is a detailed reference. Figure 16The diagram illustrates a structural schematic suitable for implementing an electronic device according to embodiments of the present invention. The electronic device may include a processor (e.g., a central processing unit, graphics processor, etc.) 001, which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 002 or a program loaded from memory 008 into random access memory (RAM) 003. The RAM 003 also stores various programs and data required for the operation of the electronic device. The processor 001, ROM 002, and RAM 003 are interconnected via bus 004. An input / output (I / O) interface 005 is also connected to bus 004.

[0077] Typically, the following devices can be connected to I / O interface 005: input devices 006 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 007 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; memory devices 008 including, for example, magnetic tapes, hard disks, etc.; and communication devices 009. Communication device 009 allows electronic devices to exchange data via wireless or wired communication with other devices. Although Figure 16 Electronic devices with various devices are shown, but it should be understood that it is not required to implement or have all of the devices shown, and more or fewer devices may be implemented or have instead.

[0078] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication device 009, or installed from memory 008, or installed from ROM 002. When the computer program is executed by processor 001, it performs the functions defined in the multi-pulse inverter control method of the embodiments of the present invention.

[0079] Figure 16 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments of the present invention.

[0080] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the multi-pulse inverter control method shown in the above embodiments is implemented.

[0081] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0082] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A multi-pulse inverter control method, characterized in that, The method is applied to perform multi-pulse testing on a TNPC inverter, where the DC side of the inverter is connected to DC power and the AC side is short-circuited. When performing a multi-pulse test on any bridge arm switch of any phase, the control method includes: The bridge arm switch transistor is used as the target switch transistor; The magnetization circuit is constructed by the bridge arm switch of this phase and the opposing bridge arm switches of the other two phases; the freewheeling circuit is constructed by the freewheeling switch of this phase and the freewheeling switch of the other two phases. Alternately construct magnetization circuit and freewheeling circuit, and when the test conditions are met, block the waveform, test and record the characteristic parameters of the target switching transistor; When performing a pulse test on any freewheeling switch in any phase, the control method includes: Use the freewheeling switch as the target switch. The magnetization circuit is constructed by the freewheeling switch of this phase and the bridge arm switches of the other two phases; the freewheeling circuit is constructed by the freewheeling switch of this phase and the freewheeling switches of the other two phases. The magnetization circuit and the freewheeling circuit are constructed alternately. When the test conditions are met, the waveform is blocked, and the characteristic parameters of the target switching transistor are tested and recorded.

2. The multi-pulse inverter control method according to claim 1, characterized in that, When performing a multi-pulse test on the upper arm switch of any phase, taking that phase as the target phase and that upper arm switch as the target switch, the process of constructing the magnetization circuit and the freewheeling circuit includes: The first freewheeling switch of the target phase is continuously turned on and the lower bridge arm switch is continuously turned off. The upper bridge arm switch and the second freewheeling switch of the target phase are turned on and off alternately. The upper and lower bridge arm switches of the other two phases are kept off, while the first and second freewheeling switches of the other two phases are kept on. When the upper arm switch of the target phase is turned on and the second freewheeling switch is turned off, the magnetization circuit is formed by the upper arm switch of the target phase and the first freewheeling switch and the second freewheeling switch of the other two phases. When the upper arm switch of the target phase is turned off and the second freewheeling switch is turned on, the freewheeling circuit is formed by the first freewheeling switch and the second freewheeling switch of each phase.

3. The multi-pulse inverter control method according to claim 1, characterized in that, When performing a multi-pulse test on the first freewheeling switch of any phase, taking that phase as the target phase and the first freewheeling switch as the target switch, the process of constructing the magnetization circuit and the freewheeling circuit includes: The upper and lower bridge arm switches of the target phase are continuously turned off, while the first and second freewheeling switches of the target phase are continuously turned on. The upper arm switches of the other two phases are continuously turned off and the second freewheeling switch is continuously turned on. The first freewheeling switch and the lower arm switches of the other two phases are alternately turned on and off. When the first freewheeling switch of the other two phases is turned off and the lower bridge arm switch is turned on, the magnetization circuit is formed by the first freewheeling switch of the target phase, the second freewheeling switch of the target phase, and the lower bridge arm switch of the other two phases. When the first freewheeling switch of the other two phases is turned on and the lower bridge arm switch is turned off, the freewheeling circuit is formed by the first freewheeling switch and the second freewheeling switch of each phase.

4. The multi-pulse inverter control method according to claim 1, characterized in that, When performing a multi-pulse test on the second freewheeling switch of any phase, taking that phase as the target phase and the second freewheeling switch as the target switch, the process of constructing the magnetization circuit and the freewheeling circuit includes: The upper and lower bridge arm switches of the target phase are continuously turned off, while the first and second freewheeling switches of the target phase are continuously turned on. The lower bridge arm switches of the other two phases are continuously turned off and the first freewheeling switch is continuously turned on. The second freewheeling switch and the upper bridge arm switches of the other two phases are alternately turned on and off. When the upper arm switches of the other two phases are turned on and the second freewheeling switch is turned off, the magnetization circuit is formed by the first freewheeling switch of the target phase, the second freewheeling switch of the target phase, and the upper arm switches of the other two phases. When the upper arm switches of the other two phases are turned off and the second freewheeling switch is turned on, the freewheeling circuit is formed by the first freewheeling switch and the second freewheeling switch of each phase.

5. The multi-pulse inverter control method according to claim 1, characterized in that, When performing a multi-pulse test on the lower bridge arm switch of any phase, taking that phase as the target phase and that lower bridge arm switch as the target switch, the process of constructing the magnetization circuit and the freewheeling circuit includes: The second freewheeling switch of the target phase is continuously turned on and the upper bridge arm switch is continuously turned off. The lower bridge arm switch of the target phase and the first freewheeling switch of the target phase are alternately turned on and off. The upper and lower bridge arm switches of the other two phases are kept off, while the first and second freewheeling switches of the other two phases are kept on. When the lower bridge arm switch of the target phase is turned on and the first freewheeling switch is turned off, the magnetization circuit is formed by the lower bridge arm switch of the target phase and the first freewheeling switch and the second freewheeling switch of the other two phases. When the lower arm switch of the target phase is turned off and the first freewheeling switch is turned on, the freewheeling circuit is formed by the first freewheeling switch and the second freewheeling switch of each phase.

6. The multi-pulse inverter control method according to claim 1, characterized in that, The process of blocking the wave when the test conditions are met includes: When the inductor current of the inverter reaches a preset current threshold, it triggers the blocking action of all transistors.

7. The multi-pulse inverter control method according to any one of claims 1-6, characterized in that, The multi-pulse test process includes: Within one pulse cycle, a complete test pulse is obtained by alternately constructing the magnetization circuit and the freewheeling circuit; By controlling the inverter transistor drive timing, the process of "obtaining a complete test pulse by alternately constructing a magnetization circuit and a freewheeling circuit within one pulse cycle" is repeatedly and alternately executed to obtain multiple consecutive test pulses; During the continuous cycle of multiple pulse cycles, the inverter inductor current change is monitored in real time until the current value rises to the preset overcurrent protection threshold.

8. A multi-pulse inverter control device, characterized in that, Based on the multi-pulse inverter control method according to any one of claims 1-6, the apparatus comprises: The first test module is used to perform a multi-pulse test on any bridge arm switch of any phase. The control method includes: taking the bridge arm switch as the target switch; constructing a magnetization circuit through the bridge arm switch of the phase and the opposing bridge arm switches of the other two phases; constructing a freewheeling circuit through the freewheeling switch of the phase and the freewheeling switches of the other two phases; alternately constructing the magnetization circuit and the freewheeling circuit; blocking the wave when the test conditions are met; testing and recording the characteristic parameters of the target switch. The second test module is used to perform pulse testing on any freewheeling switch in any phase. The control method includes: using the freewheeling switch as the target switch; constructing a magnetization circuit through the freewheeling switch of the phase and the bridge arm switches of the other two phases; constructing a freewheeling circuit through the freewheeling switch of the phase and the freewheeling switches of the other two phases; alternately constructing the magnetization circuit and the freewheeling circuit; blocking the wave when the test conditions are met; and testing and recording the characteristic parameters of the target switch.

9. An electronic device, characterized in that, include: A memory and a processor are communicatively connected, the memory stores computer instructions, and the processor executes the computer instructions to perform the multi-pulse inverter control method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to execute the multi-pulse inverter control method according to any one of claims 1 to 7.

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