PCU driving system current fault diagnosis and protection method, storage medium and equipment

Abstract

The invention discloses a PCU driving system current fault diagnosis and protection method, a storage medium and equipment, and belongs to the field of motor driving, and the method mainly comprises the steps: building a driving system analysis model, and grading different current states of a driving system; continuously carrying out spectral analysis on the current information, judging the current state of the driving system, if the driving system is in a safe state, carrying out three-phase current amplitude and phase diagnosis, continuously carrying out spectral analysis, inputting the safe information into the analytical model, and calibrating the analytical model; if so, carrying out rapid diagnosis through an analytical model, and upgrading or degrading the diagnosis state through a diagnosis result; meanwhile, a calibration signal is input through the analytical model, an abnormal situation is tried to be repaired, and the repairing effect is judged; wherein, if an obvious abnormity occurs or a current abnormity which cannot be repaired occurs, a dangerous state is entered; and when in a dangerous state, current output is closed, fault judgment is carried out, and different fault control measures are implemented according to fault types. Through cooperation of the signal processing method and the analytical model method, the problems that an existing signal processing method is poor in interference resistance and difficult in feature value selection are solved, and the problem that accurate modeling is difficult in the analytical model method is also solved.

Description

Technical Field

[0001] The present invention relates to the field of motor drive, and in particular to a current fault diagnosis and protection method, storage medium and device for a PCU drive system. Background Art

[0002] In motor drive technology, the key to achieving motor drive lies in accurate and stable current control. If there is a problem with the current control and the motor fails, there may be risks such as equipment damage, safety accidents, and economic losses. Therefore, the diagnosis and protection methods of current faults are the key to maintaining safe, stable and efficient operation of motor control systems.

[0003] Current current fault diagnosis technology mainly uses signal processing to extract current fault characteristic values ​​or thresholds for diagnosis. A small number of methods use machine learning algorithms to build analytical models for diagnosis. However, the existing diagnostic methods have the following defects and deficiencies:

[0004] 1. Existing diagnostic methods usually use a single technology, which has limitations in diagnostic effect and is not suitable for working in complex environments. In addition, existing diagnostic technologies have poor anti-interference performance in complex working environments, and when affected by external interference, the accuracy of fault diagnosis will decrease;

[0005] 2. Advanced neural network technology can overcome external interference, but the maintenance cost is high and the response speed is slow, which cannot meet the real-time diagnosis requirements;

[0006] 3. The system has poor compatibility. Different motor systems have different fault characteristics, and it is necessary to extract fault characteristic values ​​for different motor systems for diagnosis.

[0007] Existing current protection technologies include overcurrent protection, short-circuit protection, current balance protection and other methods. These technologies mainly rely on real-time current information for judgment. They can determine the stable operation of the PCU drive system to a certain extent, but they are easily affected by interference, resulting in error-triggered protection and causing equipment shutdown. In addition, their response speed is limited in a high-speed changing current environment. Summary of the invention

[0008] The purpose of the present invention is to overcome the technical problems existing in the prior art and to provide a method, storage medium and device for current fault diagnosis and protection of a PCU drive system.

[0009] The objective of the present invention is achieved through the following technical solutions:

[0010] In a first aspect, a method for current fault diagnosis and protection of a PCU drive system is provided, comprising the following steps:

[0011] S1. Build a drive system analysis model and classify different current states of the drive system, wherein the different current states include a safe state, an alarm state, and a dangerous state; the safe state and the alarm state are also called two secondary diagnosis states, and the dangerous state is a primary protection state;

[0012] S2. Acquire the operation information collected in the drive system, and determine the safety state of the drive system according to the operation information;

[0013] S3, continuously perform spectrum analysis on the current information to determine the current state of the drive system. If it is in a safe state, proceed to step S4; if it is in an alarm state, proceed to step S5;

[0014] S4, perform three-phase current amplitude and phase diagnosis and continue spectrum analysis, input safety information and calibrate the analytical model;

[0015] S5, perform rapid diagnosis through the analytical model and upgrade or downgrade the diagnostic status through the diagnostic results; at the same time, input the calibration signal through the analytical model, try to repair the abnormal situation, and judge the repair effect; if there is an obvious abnormality or the current abnormality cannot be repaired, enter the dangerous state and proceed to step S6;

[0016] S6. Turn off the current output, make a fault diagnosis, and implement different fault control measures according to the fault type.

[0017] In some embodiments, the step S2 of obtaining the driving system operation information includes:

[0018] The three-phase current, motor resolver signal, motor temperature and IGBT temperature of the drive system are obtained through various sensors in the drive system, wherein the motor resolver signal includes the motor rotation electrical angle and electrical speed.

[0019] In some embodiments, determining the safety state of the drive system according to the operation information in step S2 includes:

[0020] Set the operation safety threshold of each operation information, such as setting the three-phase current threshold, motor temperature threshold, etc. to ensure that the current output is within a reasonable range, and judge in real time whether the drive system is in a safe operating environment based on the operation safety threshold, and ensure that the current sensor is in normal working condition.

[0021] In some embodiments, ensuring that the current sensor is in a normal working state includes:

[0022] The third phase current calculated by using two phases of the three-phase current is compared with the current collected by the current sensor to ensure the normal operation of the current sensor.

[0023] In some embodiments, the step S3 continuously performs spectrum analysis on the current information to determine the current state of the drive system, including:

[0024] The current information is spectrally analyzed for signal, and the diagnosis is classified by abnormal harmonic conditions. If the harmonic abnormality is within the normal error, the safe state is maintained. If the harmonic abnormality exceeds the normal error, the alarm state is entered.

[0025] In some embodiments, determining the repair effect in step S5 includes:

[0026] The motor resolver signal is converted into an internal current command and compared with the collected current information.

[0027] In some embodiments, the fault determination in step S6 includes:

[0028] Determine whether the fault is a hardware fault or a software control fault.

[0029] In some embodiments, different fault control measures are implemented according to the fault type in step S6, including:

[0030] If it is a hardware failure, the user will be reminded and the power will be cut off; if it is a software control failure, the user will be reminded and the backup control module will be started to output low speed operation, so that the user can park the vehicle in a safe position.

[0031] In a second aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, any one of the current fault diagnosis and protection methods described above is implemented.

[0032] In a third aspect, a current fault diagnosis and protection device is provided, including a memory and a processor, wherein the memory stores computer instructions that can be executed on the processor, and when the processor executes the computer instructions, any one of the current fault diagnosis and protection methods described is executed.

[0033] It should be further explained that the technical features corresponding to the above options can be combined or replaced with each other to form a new technical solution if there is no conflict.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present invention effectively combines a variety of diagnostic technologies for fault diagnosis. By coordinating the signal processing method with the analytical model method, it not only overcomes the problems of poor interference resistance and difficulty in eigenvalue selection of the signal processing method, but also overcomes the problem of difficulty in accurate modeling of the analytical model method, while avoiding the use of high-cost and high-demand data-driven methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A flow chart of a method for current fault diagnosis and protection of a PCU drive system according to an embodiment of the present invention;

[0037] Figure 2 A step diagram of a specific current fault diagnosis and protection method for a PCU drive system according to an embodiment of the present invention;

[0038] Figure 3 The flowchart of the implementation of the PCU drive system current fault diagnosis and protection method in three states shown in the embodiment of the present invention. DETAILED DESCRIPTION

[0039] The technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various configurations. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] It should be noted that the defects existing in the solutions in the above-mentioned prior art are the results obtained by the inventor after practice and careful research. Therefore, the discovery process of the above-mentioned problems and the solutions proposed in the embodiments of the present application for the above-mentioned problems below should all be the contributions made by the inventor to the present application in the process of invention and creation, and should not be understood as technical contents known to technical personnel in this field.

[0041] In view of the technical problems pointed out in the background technology, the embodiments provided by the present invention are as follows:

[0042] Reference Figure 1 In an exemplary embodiment, a PCU drive system current fault diagnosis and protection method is provided, comprising the following steps:

[0043] S1. Build a drive system analysis model and classify different current states of the drive system, wherein the different current states include a safe state, an alarm state, and a dangerous state; the safe state and the alarm state are also called two secondary diagnosis states, and the dangerous state is a primary protection state;

[0044] S2. Acquire the operation information collected in the drive system, and determine the safety state of the drive system according to the operation information;

[0045] S3, continuously perform spectrum analysis on the current information to determine the current state of the drive system. If it is in a safe state, proceed to step S4; if it is in an alarm state, proceed to step S5;

[0046] S4, perform three-phase current amplitude and phase diagnosis and continue spectrum analysis, input safety information and calibrate the analytical model;

[0047] S5, perform rapid diagnosis through the analytical model and upgrade or downgrade the diagnostic status through the diagnostic results; at the same time, input the calibration signal through the analytical model, try to repair the abnormal situation, and judge the repair effect; if there is an obvious abnormality or the current abnormality cannot be repaired, enter the dangerous state and proceed to step S6;

[0048] S6. Turn off the current output, make a fault diagnosis, and implement different fault control measures according to the fault type.

[0049] The present invention effectively combines a variety of diagnostic technologies for fault diagnosis. By coordinating the signal processing method with the analytical model method, the judgment result of the signal processing method is used as the calibration information of the analytical model. It not only overcomes the problems of poor anti-interference and difficulty in eigenvalue selection of the signal processing method, but also overcomes the problem of difficulty in accurate modeling of the analytical model method, while avoiding the use of high-cost and high-demand data-driven methods.

[0050] In one example, a specific PCU drive system current fault diagnosis and protection method is given based on the above method, referring to Figure 2 , the fault diagnosis and protection method shown includes the following steps:

[0051] S10 obtains the operation information of the drive system through various sensors in the drive system, including but not limited to: three-phase current, motor resolver signal, motor temperature, IGBT temperature, etc.;

[0052] S20 sets safe and reasonable operating thresholds, such as phase current thresholds, motor temperature thresholds, and IGBT temperature thresholds, to ensure that the current output of the drive system is within a reasonable range and the hardware operates in a safe environment;

[0053] S30 continuously uses two phases of the three-phase current to calculate the third phase current and compares it with the sensor sampling value to diagnose and ensure that the current sensor is in normal working condition;

[0054] S40 If the above diagnoses are all normal, the program is considered to be in a safe state. The program performs spectrum analysis on the current signal to determine whether there are abnormal harmonic components. If there are no abnormalities, the safety information is put into the analytical model for model calibration;

[0055] If there is an abnormal harmonic component in S50, the program is in an alarm state. The program quickly diagnoses whether there is an abnormality in the current signal through an analytical model. If there is no abnormality, the program returns to a safe state;

[0056] S60 If the analytical model diagnoses that the current signal is abnormal, it will actively input calibration information to perform fault self-repair, and compare it with the internal current command of the system after conversion through the motor resolver signal;

[0057] S70 If the self-repair is successful, the program returns to a safe state; if the self-repair is not possible, the program enters a dangerous state;

[0058] When the S80 program is in a dangerous state, the fault status is judged according to the fault information. If the fault is a hardware fault, the power is cut off, the trailer condition is unlocked and feedback is given to the user; if the fault is a software control fault, the backup low-output drive module is started for low-speed driving for a short period of time, so that the user can park the vehicle in a safe position.

[0059] Furthermore, the safe state, alarm state and dangerous state mentioned in the PCU drive system current fault diagnosis and protection method of the present invention are only used as a sign for taking different measures for different situations during program operation, and have no other meaning. Figure 3 , specifically analyze the specific processes and measures under the three states. The overall can be divided into three parts.

[0060] Part 1: When the drive system is started, the program starts to obtain the signals of each sensor. When the current program is in a safe state, it executes in a loop. Figure 3 The diagnostic measures in the safe state are marked in the figure. Simple and fast preliminary diagnosis is performed by judging whether the three-phase current output is within the safe range, whether the current sensor function is normal, and performing current signal spectrum analysis. In the case of safe diagnosis, the safety information is fed back to the analytical model for model calibration.

[0061] Part 2: When the current signal is diagnosed to be abnormal in the safe state, the program enters the alarm state and executes the following Figure 3 The diagnostic and protective measures under the alarm state are marked in the middle. The abnormal situation of the current signal is quickly judged through the analytical model, and interference factors are eliminated. If the current signal is abnormal, the analog signal is input through the analytical mode for self-repair processing. If the repair is successful, it returns to a safe state.

[0062] Part 3: When a hardware fault is found in the safe state or the software is found to be uncontrollable in the alarm state, the program enters a dangerous state and performs corresponding crisis processing according to the diagnosis. If the fault is a hardware fault, the fault information will be fed back to the user and the drive power will be cut off; if the fault is a software fault, the fault information will be fed back to the user, the power supply of the main drive module will be cut off, and the backup drive module will be started to ensure low-speed drive output in a short time, so that the user can park the vehicle in a safe position.

[0063] In another exemplary embodiment, based on the same inventive concept as the method embodiment, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the PCU drive system current fault diagnosis and protection method provided in the embodiment of the present invention is implemented. Based on such an understanding, the technical solution of this embodiment, in essence, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0064] In another exemplary embodiment, based on the same inventive concept as Example 1, a PCU drive system current fault diagnosis and protection device is provided, including a memory and a processor, the memory stores computer instructions that can be executed on the processor, and the processor executes the PCU drive system current fault diagnosis and protection method provided by the embodiment of the present invention when running the computer instructions.

[0065] The processor may be a single-core or multi-core central processing unit or a specific integrated circuit, or one or more integrated circuits configured to implement the present invention.

[0066] Embodiments of the subject matter and functional operations described in this specification may be implemented in: tangibly embodied computer software or firmware, computer hardware including the structures disclosed in this specification and their structural equivalents, or a combination of one or more of them. Embodiments of the subject matter described in this specification may be implemented as one or more computer programs, i.e., one or more modules of computer program instructions encoded on a tangible, non-transitory program carrier to be executed by a data processing device or to control the operation of the data processing device. Alternatively or additionally, the program instructions may be encoded on an artificially generated propagated signal, such as a machine-generated electrical, optical, or electromagnetic signal, which is generated to encode and transmit information to a suitable receiver device for execution by the data processing device.

[0067] The processes and logic flows described in this specification can be performed by one or more programmable computers executing one or more computer programs to perform corresponding functions by operating on input data and generating output. The processes and logic flows can also be performed by special purpose logic circuits, such as FPGAs (field programmable gate arrays) or ASICs (application-specific integrated circuits), and the apparatus can also be implemented as special purpose logic circuits.

[0068] Processors suitable for executing computer programs include, for example, general and / or special microprocessors, or any other type of central processing unit. Typically, the central processing unit will receive instructions and data from a read-only memory and / or a random access memory. The basic components of a computer include a central processing unit for implementing or executing instructions and one or more memory devices for storing instructions and data. Typically, the computer will also include one or more large-capacity storage devices for storing data, such as magnetic disks, magneto-optical disks, or optical disks, or the computer will be operably coupled to this large-capacity storage device to receive data from it or to transmit data to it, or both. However, the computer does not necessarily have such a device. In addition, the computer can be embedded in another device, such as a mobile phone, a personal digital assistant (PDA), a mobile audio or video player, a game console, a global positioning system (GPS) receiver, or a portable storage device such as a universal serial bus (USB) flash drive, just to name a few.

[0069] It should be understood that each box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a sequence different from that marked in the accompanying drawings. For example, two continuous boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs the specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0070] The above specific implementation methods are detailed descriptions of the present invention. It cannot be determined that the specific implementation methods of the present invention are limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions and substitutions can be made without departing from the concept of the present invention, which should be regarded as belonging to the protection scope of the present invention.

Claims

1. A PCU drive system current fault diagnosis and protection method, characterized in that: The following steps are involved: S1. Build a drive system analytical model and classify different current states of the drive system, wherein the different current states include a safe state, an alarm state, and a dangerous state; S2. Acquire operation information of the drive system, and determine the safety state of the drive system according to the operation information; S3, continuously perform spectrum analysis on the current information to determine the current state of the drive system. If it is in a safe state, proceed to step S4; if it is in an alarm state, proceed to step S5; S4, perform three-phase current amplitude and phase diagnosis and continue spectrum analysis, input safety information and calibrate the analytical model; S5, quickly diagnose through the analytical model and upgrade or downgrade the diagnostic status according to the diagnostic results; at the same time, input the calibration signal through the analytical model, try to repair the abnormal situation, and judge the repair effect; if there is an obvious abnormality or the current abnormality cannot be repaired, enter the dangerous state and proceed to step S6; S6. Turn off the current output, make a fault diagnosis, and implement different fault control measures according to the fault type.

2. The PCU drive system current fault diagnosis and protection method according to claim 1, characterized in that: The step S2 of obtaining the driving system operation information includes: The three-phase current, motor resolver signal, motor temperature and IGBT temperature of the drive system are obtained through various sensors in the drive system.

3. The PCU drive system current fault diagnosis and protection method according to claim 2 is characterized in that: Determining the safety state of the drive system according to the operation information in step S2 includes: An operation safety threshold value of each operation information is set, and whether the drive system is in a safe operation environment is determined in real time according to the operation safety threshold value, and the current sensor is ensured to be in a normal working state.

4. The PCU drive system current fault diagnosis and protection method according to claim 3 is characterized in that: The step of ensuring that the current sensor is in a normal working state includes: The third phase current calculated by using two phases of the three-phase current is compared with the current collected by the current sensor.

5. The PCU drive system current fault diagnosis and protection method according to claim 1, characterized in that: The step S3 continuously performs spectrum analysis on the current information to determine the current state of the drive system, including: Abnormal harmonic conditions are classified and processed. If the harmonic abnormality is within the normal error, the safe state is maintained. If the harmonic abnormality exceeds the normal error, the alarm state is entered.

6. The PCU drive system current fault diagnosis and protection method according to claim 2, characterized in that: Determining the repair effect in step S5 includes: The motor resolver signal is converted into an internal current command and compared with the collected current information.

7. The PCU drive system current fault diagnosis and protection method according to claim 1, characterized in that: The fault determination in step S6 includes: Determine whether the fault is a hardware fault or a software control fault.

8. The PCU drive system current fault diagnosis and protection method according to claim 7, characterized in that: In step S6, different fault control measures are implemented according to the fault type, including: If it is a hardware failure, the user will be reminded and the power will be cut off; if it is a software control failure, the user will be reminded and the backup control module will be started to output low speed operation, so that the user can park the vehicle in a safe position.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the current fault diagnosis and protection method described in any one of claims 1 to 8 is implemented.

10. A current fault diagnosis and protection device, comprising a memory and a processor, wherein the memory stores computer instructions that can be executed on the processor, characterized in that: When the processor runs the computer instructions, it executes the current fault diagnosis and protection method described in any one of claims 1-8.

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