Method and device for evaluating performance of inverter of electric drive system and program product

Abstract

The embodiment of the invention provides an electric drive system inverter performance evaluation method and device and a program product, and particularly relates to the technical field of inverters. The potential performance problem of the electric drive system can be found in time under the condition that the equipment does not need to be tested offline, and shutdown or safety accidents caused by faults of the electric drive system are avoided. And moreover, performance evaluation can be carried out when the electric drive system operates normally, additional test equipment or complex disassembly steps are not needed, and the evaluation efficiency and convenience are improved. The method comprises the following steps: acquiring a gate-emitter voltage drop signal and an electrode-emitter voltage drop signal of any switch tube in the electric driving system; determining the turn-on time and turn-off time of a switching tube according to the gate emitter voltage drop signal and the electrode emitter voltage drop signal; and evaluating the performance degradation state of the switching tube according to the conduction time and the turn-off time of the switching tube.

Description

Technical Field

[0001] The present application relates to the field of inverter technology, and in particular to a method, device, and program product for evaluating the performance of an inverter in an electric drive system. Background Art

[0002] As the power source for weapons and equipment, the electric drive system integrates mechanical and electrical functions such as control and power conversion, actuators, etc. The electric drive system needs to operate for a long time without faults to ensure power output. The inverter, as an important component of the electric drive system, has the function of converting and outputting energy. The inverter converts DC power into fixed-frequency, fixed-voltage or frequency-modulated, voltage-regulated AC power, which is used to drive the motor to achieve motion control or energy conversion. The inverter has the characteristics of fast start-up, high conversion efficiency and strong adaptability.

[0003] The inverter power switches in electric drive systems are subject to the multi-physics stresses of their operating profiles. Aging of the chip's internal components, package bonds, and pins can lead to gate failure, bond cracking, and thermal breakdown. These can even cause the switches to open or short, drawing high current and burning the inverter. Inverter failures can cause equipment downtime or loss of functionality, impacting the normal operation of manufacturing and equipment, reducing efficiency and increasing costs. They can even lead to serious consequences such as equipment or equipment loss of control, fire, and burnout. This poses a serious threat to the performance of electric drive systems in harsh operating environments such as high altitude, high vibration, high temperature, high humidity, high electromagnetic interference, and high loads.

[0004] However, in traditional performance evaluation tests of electric drive systems, switching devices such as IGBTs (Insulated Gate Bipolar Transistors) or MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) need to be measured offline using dedicated semiconductor analysis instruments for their dynamic and static parameters. The power devices must be removed from the circuit board for testing and then soldered back together for continued use if they are intact. Therefore, real-time online monitoring of the inverter in the electric drive system is impossible, which increases the complexity of the inverter performance test steps for the electric drive system. Summary of the Invention

[0005] Based on this, it is necessary to provide an evaluation method for the inverter performance of an electric drive system to address the above technical issues, including:

[0006] Obtaining a gate-emitter voltage drop signal and a gate-emitter voltage drop signal of any switch tube in the electric drive system, wherein the electric drive system includes a plurality of the switch tubes, and the switch tubes are alternately turned on;

[0007] Determining the on-time and off-time of the switch tube according to the gate-emitter voltage drop signal and the electrode-emitter voltage drop signal;

[0008] The performance degradation state of the switching tube is evaluated according to the on-time of the switching tube and the off-time of the switching tube.

[0009] In some embodiments, obtaining a gate-emitter voltage drop signal and a gate-emitter voltage drop signal of any switch tube in the electric drive system includes:

[0010] Obtaining a driving timing of each of the switching tubes in the electric drive system;

[0011] According to the driving timing of each of the switching tubes, the gate-emitter voltage drop signal and the gate-emitter voltage drop signal of the corresponding switching tube in the electric drive system are obtained.

[0012] In some embodiments, the electric drive system is an electric drive system controlled according to a space vector pulse width modulation algorithm.

[0013] In some embodiments, determining the on-time and off-time of the switch tube according to the gate-emitter voltage drop signal and the electrode-emitter voltage drop signal includes:

[0014] The on-time of the switch tube is the time interval between a first moment and a second moment of the switch tube, wherein the first moment is the moment when the gate-emitter voltage drop signal switches from a low level to a high level, and the second moment is the moment when the gate-emitter voltage drop signal switches from a high level to a low level;

[0015] The turn-off time of the switching tube is the time interval between the third moment and the fourth moment of the switching tube, wherein the third moment is the moment when the gate-emitter voltage drop signal switches from a high level to a low level, and the fourth moment is the moment when the gate-emitter voltage drop signal switches from a low level to a high level.

[0016] In some embodiments, before the step of evaluating the performance degradation state of the switch tube according to the on-time and the off-time of the switch tube, the method further includes:

[0017] Obtaining a preset on-time and a preset off-time of the switch tube;

[0018] The evaluating the performance degradation state of the switching tube according to the on-time and the off-time of the switching tube includes:

[0019] comparing the on-time of the switch tube with the preset on-time of the switch tube to evaluate a degradation state of the on-performance of the switch tube;

[0020] The turn-off time of the switch tube is compared with the preset turn-off time of the switch tube to evaluate the turn-off performance degradation state of the switch tube.

[0021] In some embodiments, comparing the on-time of the switch tube with the preset on-time of the switch tube to evaluate the conduction performance degradation state of the switch tube includes:

[0022] When the on-time of the switch tube is greater than the preset on-time of the switch tube, determining that there is an abnormality in the conduction of the switch tube, wherein the preset on-time is determined according to the original on-time of the switch tube;

[0023] The comparing the turn-off time of the switch tube with the preset turn-off time of the switch tube to evaluate the turn-off performance degradation state of the switch tube includes:

[0024] When the turn-off time of the switch tube is greater than the preset turn-off time of the switch tube, it is determined that there is an abnormality in the turn-off of the switch tube, wherein the preset turn-off time is determined according to the original turn-off time of the switch tube.

[0025] In some embodiments, evaluating the performance degradation state of the switch tube according to the on-time and the off-time of the switch tube includes:

[0026] Obtaining the number of abnormalities in the on-state and the number of abnormalities in the off-state of the switch tube;

[0027] The performance degradation state of the switching tube is determined according to the number of times the switching tube is abnormally turned on and the number of times the switching tube is abnormally turned off.

[0028] In some embodiments, evaluating the performance degradation state of the switch tube according to the on-time and the off-time of the switch tube includes:

[0029] Determining a conduction degradation rate of the switch tube and a turn-off degradation rate of the switch tube according to the conduction time of the switch tube in multiple conduction stages and the turn-off time of the switch tube in multiple turn-off stages;

[0030] The failure time of the switching tube is determined according to the on-degradation speed of the switching tube and the off-degradation speed of the switching tube.

[0031] In a second aspect, a device for evaluating the performance of an inverter of an electric drive system is provided, comprising:

[0032] a signal acquisition module, configured to acquire a gate-emitter voltage drop signal and a gate-emitter voltage drop signal of any switch tube in the electric drive system, wherein the electric drive system includes a plurality of the switch tubes, and the switch tubes are turned on alternately;

[0033] a time determination module, configured to determine the on-time and off-time of the switch tube according to the gate-emitter voltage drop signal and the electrode-emitter voltage drop signal;

[0034] A performance evaluation module is used to evaluate the performance degradation state of the switch tube according to the on-time of the switch tube and the off-time of the switch tube.

[0035] In a third aspect, a computer program product is provided, comprising a computer program, which, when executed by a processor, implements the steps of the method for evaluating the performance of an inverter of an electric drive system as described in any one of the first aspects.

[0036] The electric drive system inverter performance evaluation method, device, and program product provided in the embodiments of the present application can obtain the on and off time of the switch tube in real time during the operation of the electric drive system by monitoring the gate-emitter voltage drop signal and the gate-emitter voltage drop signal of the switch tube, and then determine the performance degradation state of the switch tube through the on and off time of the switch tube. Without the need to take the equipment offline for testing, potential performance problems of the electric drive system can be discovered in a timely manner to avoid downtime or safety accidents caused by electric drive system failures. In addition, performance evaluation can be performed when the electric drive system is operating normally, without the need for additional testing equipment or complicated disassembly steps, thereby improving the efficiency and convenience of the evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0038] Figure 1 A schematic flow chart of a method for evaluating the performance of an inverter of an electric drive system provided in an embodiment of the present application;

[0039] Figure 2 A schematic circuit diagram of an electric drive system equivalent circuit in a method for evaluating inverter performance of an electric drive system provided in an embodiment of the present application;

[0040] Figure 3A schematic flow chart of another method for evaluating the performance of an inverter of an electric drive system provided in an embodiment of the present application;

[0041] Figure 4 A schematic graph of the on-off time in another method for evaluating the performance of an inverter of an electric drive system provided in an embodiment of the present application;

[0042] Figure 5 A schematic structural diagram of a device for evaluating the performance of an inverter of an electric drive system provided in an embodiment of the present application;

[0043] Figure 6 A schematic structural diagram of a computer program product provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0045] As the power source for weapons and equipment, the electric drive system integrates mechanical and electrical functions such as control and power conversion, actuators, etc. The electric drive system needs to operate for a long time without faults to ensure power output. The inverter, as an important component of the electric drive system, has the function of converting and outputting energy. The inverter converts DC power into fixed-frequency, fixed-voltage or frequency-modulated, voltage-regulated AC power, which is used to drive the motor to achieve motion control or energy conversion. The inverter has the characteristics of fast start-up, high conversion efficiency and strong adaptability.

[0046] The inverter power switches in electric drive systems are subject to the multi-physics stresses of their operating profiles. Aging of the chip's internal components, package bonds, and pins can lead to gate failure, bond cracking, and thermal breakdown. These can even cause the switches to open or short, drawing high current and burning the inverter. Inverter failures can cause equipment downtime or loss of functionality, impacting the normal operation of manufacturing and equipment, reducing efficiency and increasing costs. They can even lead to serious consequences such as equipment or equipment loss of control, fire, and burnout. This poses a serious threat to the performance of electric drive systems in harsh operating environments such as high altitude, high vibration, high temperature, high humidity, high electromagnetic interference, and high loads.

[0047] However, conventional technology tests the three-phase U / V / W signals at the output of the inverter bridge. If any transistor in any phase shorts, the effective value of the three-phase voltage will drop significantly. This phase loss phenomenon can be used to determine whether a fault has occurred due to an open circuit in one or more switching transistors. The degree of device degradation is assessed by measuring the dynamic and static parameters of switching devices such as IGBTs and MOSFETs offline using dedicated semiconductor analyzers. This makes real-time online monitoring of inverters in electric drive systems impossible, making inverter performance testing more complex.

[0048] The present application provides a method for evaluating the performance of an inverter in an electric drive system. Figure 1 ,include:

[0049] S11: Obtaining a gate-emitter voltage drop signal and a gate-emitter voltage drop signal of any switch tube in the electric drive system, wherein the electric drive system includes multiple switch tubes, and each switch tube is turned on alternately.

[0050] It should be noted that the electric drive system can adopt a three-phase full-bridge inverter structure, such as Figure 2 As shown in , it consists of multiple switching transistors (such as IGBTs or MOSFETs), which are alternately turned on to achieve power conversion and control. In the embodiment of this application, it includes six switching transistors (VT1, VT2, VT3, VT4, VT5, VT6), corresponding to the upper and lower bridge arms of the three phases (a, b, c).

[0051] For example, the gate (G), emitter (E), and collector (C) signals of the switching transistors can be introduced into the monitoring device via an isolation circuit. The isolation circuit can use optical or magnetic isolation technology to ensure the safety and accuracy of signal acquisition. The electric drive system and the test and evaluation device are connected via cables, and the gate, emitter, and collector signals of the six switching transistors are introduced into the evaluation device. A relay matrix is used to select and switch the six switching transistor signals. The relay matrix is controlled by a programmable circuit to dynamically select the switching transistor signal to be monitored. The gate-emitter voltage drop signal (Vge) is selected as the trigger signal. For example, the electric drive system's Vge uses a control logic with a positive voltage of 15V and a negative voltage of -8V. The median of the voltage difference between the two is selected as the trigger level, and a falling-edge trigger is used. Under the Vge trigger signal, the Vge and Vce signals are synchronously acquired. The acquisition device needs to have a high sampling rate (e.g., 500Ms / s) and sufficient storage capacity (e.g., 128MB / channel).

[0052] It is understandable that alternating conduction of the switching tubes can reduce the influence of coupling between different tubes on the voltage drop signal and improve the accuracy of the detection results.

[0053] S12: Determine the on-time and off-time of the switch tube according to the gate-emitter voltage drop signal and the pole-emitter voltage drop signal.

[0054] For example, see Figure 3 The gate-emitter voltage drop signal represents the voltage between the gate and emitter of the switch. The emitter voltage drop signal represents the voltage between the collector and emitter of the switch. The rising edge of the gate-emitter voltage drop signal can be used to determine the moment when the signal rises from a low level to a high level, as well as the rising period, which is the moment when the switch begins to conduct. The falling edge of the emitter voltage drop signal can be used to determine the moment when the emitter voltage drop signal falls from a high level to a low level, which is the moment when the switch is fully turned on.

[0055] S13: Evaluate the performance degradation state of the switch tube according to the on-time and the off-time of the switch tube.

[0056] For example, the actually measured on-time and off-time can be compared with the preset on-time and preset off-time. If the actually measured on-time is greater than the preset on-time and the off-time is greater than the preset off-time, the switch tube fails.

[0057] The method for evaluating the performance of the inverter of the electric drive system provided in the embodiment of the present application can obtain the on and off time of the switch tube in real time during the operation of the electric drive system by monitoring the gate-emitter voltage drop signal and the gate-emitter voltage drop signal of the switch tube, and then determine the performance degradation state of the switch tube through the on and off time of the switch tube. Without taking the equipment offline for testing, potential performance problems of the electric drive system can be discovered in a timely manner, avoiding downtime or safety accidents caused by electric drive system failures. In addition, performance evaluation can be performed when the electric drive system is operating normally, without the need for additional testing equipment or complicated disassembly steps, thereby improving the efficiency and convenience of the evaluation.

[0058] In some embodiments, obtaining a gate-emitter voltage drop signal and a gate-emitter voltage drop signal of any switch tube in the electric drive system, as shown in 3, includes:

[0059] S111: Obtain the driving timing of each switch tube in the electric drive system.

[0060] For example, the drive timing refers to the turn-on and turn-off times of a particular switch. A specific control algorithm, such as SVPWM (Space Vector Pulse Width Modulation) or SPWM (Sinusoidal Pulse Width Modulation), can be used to determine the drive timing of each switch in the electric drive system.

[0061] S112: According to the driving timing of each switching tube, the gate-emitter voltage drop signal and the gate-emitter voltage drop signal of the corresponding switching tube in the electric drive system are obtained.

[0062] For example, based on the driving timing, it can be determined which switch tube needs to be monitored for voltage drop signal, thereby obtaining the gate-emitter voltage drop signal and the gate-emitter voltage drop signal of the corresponding switch tube in the corresponding electric drive system.

[0063] The electric drive system inverter performance evaluation method provided in the embodiments of this application, by real-time monitoring of the switch drive timing and related voltage signals, can promptly detect abnormal switch behavior, such as unusual changes in on-time or off-time, thereby providing early warning of potential faults and avoiding system downtime or damage caused by switch failure. By real-time monitoring of signals, potential problems can be promptly identified and addressed, reducing the occurrence of sudden failures and improving the overall reliability of the system.

[0064] In some embodiments, the electric drive system is an electric drive system controlled according to a space vector pulse width modulation algorithm.

[0065] For example, the space vector pulse width modulation algorithm can decompose the output voltage vector of the inverter into a combination of basic voltage vectors, and achieve effective drive of the motor by allocating the action time of the basic vectors. Figure 2 The equivalent circuit of the electric drive system shown in Figure 1 consists of six switches (the aforementioned IGBTs or MOSFETs), corresponding to the upper and lower legs of the three phases (a, b, and c). The combination of these switches can produce eight basic switching states: zero vectors: 000 (all upper legs off) and 111 (all lower legs off), and active vectors: 001, 010, 011, 100, 101, and 110. The switching states divide the 360-degree voltage space into six sectors, each 60 degrees. The SVPWM algorithm synthesizes the desired voltage vector by rationally allocating the action times of these basic vectors. For example, to synthesize a voltage vector within a specific sector, two active vectors and a zero vector are selected within that sector. By adjusting the ratio of their action times, the target voltage vector is approximated. Based on the calculated action times, corresponding PWM signals are generated to control the on and off of the inverter switches.

[0066] It should be noted that only one of the switch tubes is turned off each time to ensure that the correct time variable can be obtained.

[0067] In the method for evaluating inverter performance in an electric drive system provided in the embodiments of this application, the SVPWM algorithm rationally distributes the action time of the basic voltage vector, making the voltage vector output by the inverter closer to a circular rotating magnetic field, thereby reducing the motor's harmonic losses and improving its operating efficiency. SVPWM can more precisely control the motor's voltage and current, thereby improving the dynamic response performance of the motor in the electric drive system.

[0068] In some embodiments, the on-time and off-time of the switch tube are determined based on the gate-emitter voltage drop signal and the emitter voltage drop signal, including: the on-time of the switch tube is the time interval between a first moment and a second moment of the switch tube, wherein the first moment is the moment when the gate-emitter voltage drop signal switches from a low level to a high level, and the second moment is the moment when the emitter voltage drop signal switches from a high level to a low level. The off-time of the switch tube is the time interval between a third moment and a fourth moment of the switch tube, wherein the third moment is the moment when the gate-emitter voltage drop signal switches from a high level to a low level, and the fourth moment is the moment when the emitter voltage drop signal switches from a low level to a high level.

[0069] For example, the on-time refers to the time interval from the start of the switch to the complete on-time. Figure 4 The moment when the gate-emitter voltage drop signal Vge switches from a low level to a high level indicates that the control signal of the switch tube has been triggered and the switch tube begins to conduct. Figure 4 The moment the emitter-to-emitter voltage drop signal (Vce) switches from a high level to a low level, indicating that the switch is fully turned on and current begins to flow through the switch, significantly reducing the voltage drop between the emitter and the electrode. Therefore, the on-time of the switch is the interval between the first and second moments.

[0070] For example, the third moment is when the gate-emitter voltage drop signal Vge switches from a high level to a low level, indicating that the control signal of the switch has been removed and the switch begins to turn off. The fourth moment is when the gate-emitter voltage drop signal Vce switches from a low level to a high level, indicating that the switch has been completely turned off, current stops flowing through the switch, and the voltage between the gate and emitter returns to a high level. Therefore, the turn-off time of the switch is the time interval from the beginning of the switch turning off to the complete turn-off of the switch.

[0071] The method for evaluating the performance of the inverter of the electric drive system provided in the embodiment of the present application can evaluate the performance status of the switch tube in real time by accurately measuring the on-time and off-time of the switch tube, which is crucial to ensure that the switch tube operates in an efficient and safe state. Changes in the on-time and off-time of the switch tube usually indicate potential performance degradation or failure. By measuring the on-time and off-time of the switch tube, anomalies can be detected in advance to avoid system shutdown or damage caused by switch tube failure. And by monitoring the performance degradation of the switch tube, timely measures can be taken to reduce the stress of the switch tube and extend its service life, thereby improving the reliability of the entire system.

[0072] In some embodiments, before the step of evaluating the performance degradation state of the switch tube according to the on-time of the switch tube and the off-time of the switch tube, it also includes: obtaining the preset on-time of the switch tube; evaluating the performance degradation state of the switch tube according to the on-time of the switch tube and the off-time of the switch tube, including: comparing the on-time of the switch tube and the preset on-time of the switch tube to evaluate the on-performance degradation state of the switch tube; comparing the off-time of the switch tube and the preset off-time of the switch tube to evaluate the off-performance degradation state of the switch tube.

[0073] For example, if the actual on-time of the switch is greater than the preset on-time, it indicates that the on-performance of the switch may be degraded. If the actual off-time of the switch is greater than the preset off-time, it indicates that the on-performance of the switch may be degraded.

[0074] It should be noted that the degradation thresholds of the on-time and off-time can be set according to the reliability requirements of the switch tube and the actual application environment, and are not specifically limited in the embodiments of the present application.

[0075] The method for evaluating the performance of the inverter of the electric drive system provided in the embodiment of the present application can provide a performance benchmark of the switching tube under an ideal state by obtaining preset on-time and off-time. Further, by comparing the actual measured values with these preset values, the performance changes of the switching tube can be intuitively evaluated, and signs of degradation of the performance of the switching tube can be discovered in time to avoid system shutdown or damage caused by switch tube failure. By obtaining accurate on-time and off-time, the evaluation accuracy and objectivity of the method for evaluating the performance of the inverter of the electric drive system can be improved.

[0076] In some embodiments, the on-time of the switch tube and the preset on-time of the switch tube are compared to evaluate the degradation state of the on-performance of the switch tube, including: when the on-time of the switch tube is greater than the preset on-time of the switch tube, determining that there is an abnormality in the conduction of the switch tube, wherein the preset on-time is determined based on the original on-time of the switch tube; and the off-time of the switch tube and the preset off-time of the switch tube are compared to evaluate the degradation state of the off-performance of the switch tube, including: when the off-time of the switch tube is greater than the preset off-time of the switch tube, determining that there is an abnormality in the off-time of the switch tube, wherein the preset off-time is determined based on the original off-time of the switch tube.

[0077] For example, the preset on-time is the ideal on-time of the switch, i.e., when the switch is on without performance degradation. The preset off-time is the ideal off-time of the switch, i.e., when the switch is off without performance degradation. The preset on-time and preset off-time can be set based on actual application needs and reliability requirements. For example, a switch abnormality can be considered when the actual on-time or off-time exceeds 20% of the preset value.

[0078] The electric drive system inverter performance evaluation method provided in the embodiments of the present application can promptly detect signs of switch performance degradation by monitoring the on and off times of the switch in real time and comparing them with preset values. This method can provide early warning before a fault occurs, avoiding system downtime or damage caused by switch failure. In addition, in the event of an anomaly detected early, timely measures can be taken to repair or replace the device, reducing the occurrence of sudden failures and improving system reliability and stability.

[0079] In some embodiments, the performance degradation state of the switch tube is evaluated based on the on-time and the off-time of the switch tube, including: obtaining the number of times the switch tube is abnormally turned on and the number of times the switch tube is abnormally turned off; and determining the performance degradation state of the switch tube based on the number of times the switch tube is abnormally turned on and the number of times the switch tube is abnormally turned off.

[0080] For example, thresholds for the number of abnormal on-times and abnormal off-times can be set based on actual application needs and reliability requirements. For example, the threshold for abnormal on-times can be set to 10 times / day. If the number of abnormal on-times exceeds 10 times / day, the switch is considered to have performance degradation. The threshold for abnormal off-times can be set to 10 times / day. If the number of abnormal off-times exceeds 10 times / day, the switch is considered to have performance degradation.

[0081] The electric drive system inverter performance evaluation method provided in the embodiments of the present application monitors the on and off times of the switch in real time and records the number of abnormalities, enabling timely detection of signs of switch performance degradation. Furthermore, by repeatedly obtaining the number of abnormalities during on-time and off-time, the problem of a single abnormality being an erroneous monitoring result can be avoided, thereby improving the accuracy and reliability of the evaluation results.

[0082] In some embodiments, the performance degradation state of the switch tube is evaluated based on the on-time and the off-time of the switch tube, including: determining the on-degradation speed of the switch tube and the off-degradation speed of the switch tube based on the on-time of the switch tube in multiple on-stages and the off-time of the switch tube in multiple off-stages; and determining the failure time of the switch tube based on the on-degradation speed of the switch tube and the off-degradation speed of the switch tube.

[0083] For example, the on-time and off-time of the switch during multiple on- and off-phases can be collected. The on- and off-degradation rates can be calculated. The on-degradation rate can refer to the rate of change of the switch's on-time over time. Further, by analyzing the on-time data of the switch during multiple on-phases, linear regression or other statistical methods can be used to calculate the increasing trend of the on-time. By analyzing the off-time data of the switch during multiple off-phases, linear regression or other statistical methods can be used to calculate the increasing trend of the off-time, thereby predicting the failure time of the switch.

[0084] The method for evaluating the performance of the inverter of the electric drive system provided in the embodiment of the present application continuously monitors the on-time and off-time of the switching tube multiple times. When the preset on-time and preset off-time are not exceeded, the degradation rate is determined by the time change trend, and the failure time is then predicted. This ensures that the failure time is accurate data obtained after multiple accurate tests. Therefore, whether the switching tube has failed can be measured by the accurate failure time.

[0085] The present application provides an evaluation device for the performance of an inverter of an electric drive system. Figure 5 , comprising: a signal acquisition module 10, a time determination module 20, and a performance evaluation module 30. The signal acquisition module 10 is used to obtain a gate-emitter voltage drop signal and an emitter-emitter voltage drop signal of any switching tube in the electric drive system, wherein the electric drive system includes multiple switching tubes, and each switching tube is alternately turned on. The time determination module 20 is used to determine the on-time and off-time of the switching tube based on the gate-emitter voltage drop signal and the emitter-emitter voltage drop signal. The performance evaluation module 30 is used to evaluate the performance degradation state of the switching tube based on the on-time of the switching tube and the off-time of the switching tube.

[0086] This application embodiment provides a computer program product. Figure 6, including a computer program, which, when executed by a processor, implements the steps of the method for evaluating the performance of the electric drive system inverter of any one of the above embodiments.

[0087] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. In particular, any reference to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile 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 various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processors involved in the various embodiments provided herein may be, but are not limited to, general-purpose processors, central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), programmable logic devices (PLDs), data processing logic devices based on quantum computing, and the like.

[0088] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, 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 specification.

[0089] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A method for evaluating the performance of an inverter of an electric drive system, characterized in that: include: Obtaining a gate-emitter voltage drop signal and a gate-emitter voltage drop signal of any switch tube in the electric drive system, wherein the electric drive system includes a plurality of the switch tubes, and the switch tubes are alternately turned on; Determining the on-time and off-time of the switch tube according to the gate-emitter voltage drop signal and the electrode-emitter voltage drop signal; The performance degradation state of the switching tube is evaluated according to the on-time of the switching tube and the off-time of the switching tube.

2. The method for evaluating the performance of an electric drive system inverter according to claim 1, wherein: The obtaining of the gate-emitter voltage drop signal and the pole-emitter voltage drop signal of any switch tube in the electric drive system includes: Obtaining a driving timing of each of the switching tubes in the electric drive system; According to the driving timing of each of the switching tubes, the gate-emitter voltage drop signal and the gate-emitter voltage drop signal of the corresponding switching tube in the electric drive system are obtained.

3. The method for evaluating the performance of an electric drive system inverter according to claim 2, wherein: The electric drive system is an electric drive system controlled according to a space vector pulse width modulation algorithm.

4. The method for evaluating the performance of an electric drive system inverter according to claim 1, wherein: The step of determining the on-time and the off-time of the switch tube according to the gate-emitter voltage drop signal and the electrode-emitter voltage drop signal includes: The on-time of the switch tube is the time interval between a first moment and a second moment of the switch tube, wherein the first moment is the moment when the gate-emitter voltage drop signal switches from a low level to a high level, and the second moment is the moment when the gate-emitter voltage drop signal switches from a high level to a low level; The turn-off time of the switching tube is the time interval between the third moment and the fourth moment of the switching tube, wherein the third moment is the moment when the gate-emitter voltage drop signal switches from a high level to a low level, and the fourth moment is the moment when the gate-emitter voltage drop signal switches from a low level to a high level.

5. The method for evaluating the performance of an electric drive system inverter according to claim 1, wherein: Before the step of evaluating the performance degradation state of the switch tube according to the on-time and the off-time of the switch tube, the method further includes: Obtaining a preset on-time and a preset off-time of the switch tube; The evaluating the performance degradation state of the switching tube according to the on-time and the off-time of the switching tube includes: comparing the on-time of the switch tube with the preset on-time of the switch tube to evaluate a degradation state of the on-performance of the switch tube; The turn-off time of the switch tube is compared with the preset turn-off time of the switch tube to evaluate the turn-off performance degradation state of the switch tube.

6. The method for evaluating the performance of an electric drive system inverter according to claim 5, wherein: The comparing the on-time of the switch tube with the preset on-time of the switch tube to evaluate the degradation state of the on-performance of the switch tube includes: When the on-time of the switch tube is greater than the preset on-time of the switch tube, determining that there is an abnormality in the conduction of the switch tube, wherein the preset on-time is determined according to the original on-time of the switch tube; The comparing the turn-off time of the switch tube with the preset turn-off time of the switch tube to evaluate the turn-off performance degradation state of the switch tube includes: When the turn-off time of the switch tube is greater than the preset turn-off time of the switch tube, it is determined that there is an abnormality in the turn-off of the switch tube, wherein the preset turn-off time is determined according to the original turn-off time of the switch tube.

7. The method for evaluating the performance of an electric drive system inverter according to claim 6, wherein: The evaluating the performance degradation state of the switching tube according to the on-time and the off-time of the switching tube includes: Obtaining the number of abnormalities in the on-state and the number of abnormalities in the off-state of the switch tube; The performance degradation state of the switching tube is determined according to the number of times the switching tube is abnormally turned on and the number of times the switching tube is abnormally turned off.

8. The method for evaluating the performance of an electric drive system inverter according to claim 1, wherein: The evaluating the performance degradation state of the switching tube according to the on-time and the off-time of the switching tube includes: Determining a conduction degradation rate of the switch tube and a turn-off degradation rate of the switch tube according to the conduction time of the switch tube in multiple conduction stages and the turn-off time of the switch tube in multiple turn-off stages; The failure time of the switching tube is determined according to the on-degradation speed of the switching tube and the off-degradation speed of the switching tube.

9. An evaluation device for the performance of an inverter of an electric drive system, characterized in that: include: a signal acquisition module, configured to acquire a gate-emitter voltage drop signal and a gate-emitter voltage drop signal of any switch tube in the electric drive system, wherein the electric drive system includes a plurality of the switch tubes, and the switch tubes are turned on alternately; a time determination module, configured to determine the on-time and off-time of the switch tube according to the gate-emitter voltage drop signal and the electrode-emitter voltage drop signal; A performance evaluation module is used to evaluate the performance degradation state of the switch tube according to the on-time of the switch tube and the off-time of the switch tube.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the computer program implements the steps of the method for evaluating the performance of an electric drive system inverter according to any one of claims 1 to 8.

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