Control method and system for improving torque precision of permanent magnet synchronous motor for vehicle

Abstract

The invention discloses a control method and system for improving the torque precision of a permanent magnet synchronous motor for a vehicle, and relates to the technical field of electric drive control, and the method comprises the steps: carrying out the secondary filtering of a three-phase current signal after hardware filtering processing, carrying out the analysis of the three-phase current signal after secondary filtering, and obtaining a three-phase current harmonic distortion rate; determining an optimal secondary filter coefficient by adjusting the secondary filter coefficient and combining the three-phase current harmonic distortion rate; acquiring an electrical frequency; generating a phase delay compensation amount, and combining the phase delay compensation amount with the motor position data to generate a compensated control angle; converting the three-phase current signal after secondary filtering to generate a compensated dq-axis current feedback value; and inputting the compensated dq-axis current feedback value and the calibrated dq-axis current instruction value into a PI controller for deviation adjustment, converting an adjustment result into a three-phase voltage through a three-phase inverter, and outputting the three-phase voltage to control the permanent magnet synchronous motor.

Description

Technical Field

[0001] This invention relates to the field of electric drive control technology, and in particular to a control method for improving the torque accuracy of a vehicle permanent magnet synchronous motor, a control system for improving the torque accuracy of a vehicle permanent magnet synchronous motor, electronic equipment, and storage medium. Background Technology

[0002] Permanent magnet synchronous motors, with their high efficiency, high power density, and excellent dynamic response performance, have become the core drive component of electric vehicle drive systems. Their torque control accuracy directly determines the vehicle's power, economy, and ride comfort. In a field-oriented control (FOC) architecture, motor torque is achieved through decoupled control of the dq-axis current. However, factors such as harmonic distortion of the three-phase current, sampling errors, and sensor deviations can all cause torque fluctuations.

[0003] For example, the Chinese patent, titled "A Precise Control Method for Magnetizing Current of a Memory Motor," patent number CN112671299A, discloses a precise control method for magnetizing current, including a magnetizing control module, a dq-axis feedforward current regulator, and a self-disruption current controller. By directly compensating the voltage through an extended state observer, the complexity of the control system is reduced, and it is not affected by changes in motor parameters.

[0004] For example, the Chinese patent, titled "A Control System and Method for a Permanent Magnet Synchronous Motor," patent number CN111200379A, specifically discloses that by using a drive bridge to form multiple loops in the permanent magnet synchronous motor control system, the gain of multiple current sensors is calibrated to reduce the gain deviation between sensors, reduce the second harmonic in torque fluctuations, and improve the output torque control accuracy.

[0005] For example, the Chinese patent, titled "A Method and System for Obtaining Feedback Current of a Stepper Motor Driver," patent number CN102611372A, specifically discloses a method for obtaining a sampled voltage, performing bias amplification and analog-to-digital conversion, and then calculating the feedback current by combining the driver's parameters such as bias voltage, quantitative dimensions, upper limit value of analog-to-digital conversion voltage sampling, and quantization value. The method also includes filtering the feedback current and fault monitoring.

[0006] For example, the Chinese patent, titled "A Method for Improving Motor Torque Accuracy," patent number CN112332733A, specifically discloses a method for obtaining feedback parameters through a motor controller under preset operating parameters, adjusting motor parameters to make them equal to target parameters, including adjusting the zero-point parameters of the rotary transformer, the current sampling delay time, and the current sampling gain parameters to eliminate errors and improve torque accuracy.

[0007] Existing technologies still have significant limitations: First, the optimization dimensions are relatively singular, either focusing on current tracking speed or addressing single-point issues such as sensor calibration and sampling accuracy, without forming a systematic solution to the core contradictions in the current filtering stage. In practical applications, to suppress electromagnetic interference, the three-phase current needs to undergo hardware filtering. However, hardware filtering introduces phase delay, and single hardware filtering is insufficient to completely eliminate harmonic distortion. Existing technologies do not consider the impact of phase deviation caused by filtering on coordinate transformation accuracy, which can easily lead to dq-axis current decoupling distortion and cause torque steady-state error. Second, some solutions rely on hardware circuit improvements or complex sensor calibration processes, increasing system costs and production cycles, and lacking low-cost, easily implementable pure software optimization solutions. Third, existing technologies have not constructed a synergistic mechanism of "harmonic suppression-phase compensation," failing to balance current waveform smoothness and control phase accuracy, thus limiting the improvement of torque accuracy.

[0008] Therefore, there is an urgent need for a technical solution that can simultaneously address the problems of current harmonic distortion and phase delay without requiring additional hardware investment. Summary of the Invention

[0009] In view of this, the purpose of the present invention is to provide a control method for improving the torque accuracy of a vehicle permanent magnet synchronous motor, a control system for improving the torque accuracy of a vehicle permanent magnet synchronous motor, an electronic device and a storage medium, aiming to overcome the shortcomings of the prior art and achieve the goal of improving the torque accuracy of the motor.

[0010] This invention provides the following solution:

[0011] According to an invention of the present invention, a control method for improving the torque accuracy of a vehicle permanent magnet synchronous motor is provided, comprising the following steps:

[0012] The three-phase current signal after hardware filtering is subjected to secondary filtering to obtain the secondary filtering coefficients. The three-phase current signal after secondary filtering is analyzed to obtain the three-phase current harmonic distortion rate.

[0013] The optimal secondary filter coefficient is determined by adjusting the secondary filter coefficient and combining it with the three-phase current harmonic distortion rate.

[0014] Obtain motor position data, and based on the motor position data, obtain the electrical frequency;

[0015] Based on the electrical frequency and the optimal secondary filter coefficient, the phase delay compensation is generated, and combined with the motor position data, the compensated control angle is generated.

[0016] The three-phase current signal after secondary filtering is input into the conversion algorithm, and combined with the compensated control angle, it is converted to generate the compensated dq axis current feedback value.

[0017] Obtain the calibrated dq axis current command value;

[0018] The compensated dq-axis current feedback value and the calibrated dq-axis current command value are input into the PI controller for deviation adjustment. The adjustment result is converted into three-phase voltage by the three-phase inverter and output to control the permanent magnet synchronous motor.

[0019] Further analysis of the three-phase current signal after secondary filtering includes:

[0020] Real-time detection of harmonic components and the percentage of each harmonic amplitude in three-phase current;

[0021] Evaluate whether the three-phase current harmonic distortion rate meets the preset requirements;

[0022] The preset requirement is that the harmonic distortion rate of the three-phase current is less than a preset threshold.

[0023] When the three-phase current harmonic distortion rate drops below the preset threshold, the adjustment of the secondary filter coefficient is stopped, and the current coefficient is determined to be the optimal secondary filter coefficient.

[0024] Furthermore, the generation of phase delay compensation includes:

[0025] The motor speed is obtained by integrating the motor position, and the electrical frequency is obtained after unit conversion.

[0026] The phase compensation amount is obtained based on the electrical frequency and the optimal second-order filter coefficients.

[0027] The motor position and phase compensation amount are superimposed to generate the compensated control angle.

[0028] Furthermore, including:

[0029] The transformation algorithm is the Clark+Park coordinate transformation algorithm;

[0030] The three-phase current signal after secondary filtering is mapped to a stationary two-phase coordinate system using Clark transformation;

[0031] The Park transformation decouples the current signal in the stationary two-phase coordinate system to a rotating two-phase coordinate system synchronized with the rotor magnetic field. Combined with the compensated control angle, the compensated dq-axis current feedback value is generated.

[0032] Furthermore, including:

[0033] The calibrated dq axis current command value is obtained by decoupling the motor torque command through the maximum torque-current ratio;

[0034] The maximum torque-to-current ratio is the correspondence between the dq-axis current and the torque of the permanent magnet synchronous motor as determined by the test bench calibration.

[0035] Furthermore, including:

[0036] When the PI controller performs deviation adjustment, it optimizes the adjustment result by combining the real-time detected bus voltage value.

[0037] Furthermore, including:

[0038] Motor position data is acquired through a motor resolver. The electrical frequency is generated by integrating the acquired motor position data to obtain the motor speed, followed by unit conversion.

[0039] According to a second aspect of the present invention, a control system for improving the torque accuracy of a vehicle permanent magnet synchronous motor is provided, comprising:

[0040] Hardware filtering module, secondary filtering module, filtering adjustment module, speed acquisition module, electrical frequency acquisition module, angle generation module, angle conversion module, current command value acquisition module, and deviation adjustment module;

[0041] The hardware filtering module is used to acquire the three-phase current signal of the permanent magnet synchronous motor and perform hardware filtering on the three-phase current signal of the permanent magnet synchronous motor.

[0042] The secondary filtering module is used to perform secondary filtering on the three-phase current signal after hardware filtering, obtain the secondary filtering coefficients, perform Fourier analysis on the three-phase current signal after secondary filtering, and evaluate whether the harmonic distortion rate of the three-phase current meets the preset requirements.

[0043] The filter adjustment module is used to determine the optimal secondary filter coefficient by adjusting the secondary filter coefficient and combining it with the three-phase current harmonic distortion rate.

[0044] The speed acquisition module is used to acquire motor position data and obtain the motor speed based on the motor position data.

[0045] The electrical frequency acquisition module is used to acquire the electrical frequency based on the motor speed.

[0046] An angle generation module is used to generate a phase delay compensation amount based on the electrical frequency, the optimal secondary filter coefficient, and the hardware filtering characteristics, and to generate a compensated control angle by combining the motor position data.

[0047] The angle conversion module is used to input the three-phase current data after secondary filtering into the conversion algorithm, and combine it with the compensated control angle to generate the compensated dq axis current feedback value.

[0048] The current command value acquisition module is used to acquire the calibrated dq axis current command value;

[0049] The deviation adjustment module is used to input the compensated dq axis current feedback value and the calibrated dq axis current command value into the PI controller for deviation adjustment. The adjustment result is converted into three-phase voltage by the three-phase inverter and output to control the permanent magnet synchronous motor.

[0050] According to three aspects of the present invention, an electronic device is provided, comprising: a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

[0051] The memory stores a computer program, which, when executed by a processor, causes the processor to perform steps of a control method to improve the torque accuracy of a vehicle permanent magnet synchronous motor.

[0052] According to four aspects of the present invention, a computer-readable storage medium is provided that stores a computer program executable by an electronic device, which, when run on the electronic device, causes the electronic device to perform the steps of a control method for improving the torque accuracy of a vehicle permanent magnet synchronous motor.

[0053] Compared with the prior art, the present invention has the following advantages:

[0054] This application significantly reduces the deviation between the motor torque output and the command value by reducing the current harmonic distortion rate and compensating for the phase delay.

[0055] This application improves the overall driving comfort of the vehicle by optimizing the stability of the current signal and reducing torque fluctuations caused by current fluctuations.

[0056] This application is implemented entirely in software, enabling low-cost adaptation to existing pure electric vehicle drive systems. Furthermore, through a standardized parameter adjustment process, it can be adapted to different models of permanent magnet synchronous motors, making it suitable for a wide range of applications. Attached Figure Description

[0057] 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.

[0058] Figure 1 This is a flowchart of a control method for improving the torque accuracy of a permanent magnet synchronous motor for vehicles, provided by one or more embodiments of the present invention.

[0059] Figure 2 This is a structural diagram of a control system for improving the torque accuracy of a vehicle permanent magnet synchronous motor, provided by one or more embodiments of the present invention.

[0060] Figure 3 This is a control block diagram of a permanent magnet synchronous motor provided in a specific embodiment of the present invention.

[0061] Figure 4 This is a block diagram for improving the torque accuracy control of a motor, provided in a specific embodiment of the present invention.

[0062] Figure 5 This is a schematic diagram of an angle correction module provided in a specific embodiment of the present invention.

[0063] Figure 6 This is a block diagram of the parameter adjustment of a software filtering module provided in a specific embodiment of the present invention.

[0064] Figure 7 This is a block diagram of an electronic device for a control method to improve the torque accuracy of a vehicle permanent magnet synchronous motor, provided by one or more embodiments of the present invention. Detailed Implementation

[0065] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0066] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the application. The singular forms “a,” “said,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.

[0067] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0068] It should be understood that although the terms first, second, third, etc., may be used in the embodiments of this application, these descriptions should not be limited to these terms. These terms are only used to distinguish the descriptions. For example, first may also be referred to as second without departing from the scope of the embodiments of this application, and similarly, second may also be referred to as first.

[0069] Depending on the context, the words “if” or “suppose” as used here can be interpreted as “when” or “in response to determination” or “in response to detection.” Similarly, depending on the context, the phrases “if determination” or “if detection (of the stated condition or event)” can be interpreted as “when determination” or “in response to determination” or “when detection (of the stated condition or event)” or “in response to detection (of the stated condition or event).”

[0070] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device that includes said element.

[0071] It should be noted that any symbols and / or numbers present in the specification that are not marked in the accompanying drawings are not reference numerals.

[0072] Figure 1 This is a flowchart of a control method for improving the torque accuracy of a permanent magnet synchronous motor for vehicles, provided by one or more embodiments of the present invention.

[0073] like Figure 1 As shown, it includes the following steps:

[0074] Step S1: Perform secondary filtering on the three-phase current signal after hardware filtering to obtain the secondary filtering coefficients. Analyze the three-phase current signal after secondary filtering to obtain the three-phase current harmonic distortion rate.

[0075] Specifically, the three-phase current of the permanent magnet synchronous motor is subjected to hardware filtering to obtain the hardware-filtered three-phase current. On the basis of hardware filtering, a software filtering module is added to perform software filtering on the hardware-filtered three-phase current. The software filtering coefficient is adjusted by experiment, and the harmonic distortion rate of the three-phase current is calculated by combining FFT (Fourier) analysis.

[0076] Step S2: Determine the optimal secondary filter coefficient by adjusting the secondary filter coefficient and combining it with the three-phase current harmonic distortion rate.

[0077] Specifically, the purpose of secondary filtering is to further reduce the residual three-phase current harmonics after hardware filtering. The secondary filter coefficient determines the amplitude-frequency characteristics of the filter. If the secondary filter coefficient is too large, it may lead to increased current phase delay; if the secondary harmonic coefficient is too small, it will not effectively suppress the harmonics. Therefore, by decomposing the frequency components of the three-phase current and quantifying the amplitude proportion of each harmonic, the filtering effect can be judged to determine whether it meets the standard. When the harmonic distortion rate drops below the preset threshold, the optimal parameters are determined to ensure the stability and repeatability of the filtering effect, so that the filtering parameters are accurately matched with the motor operating conditions, further improving the consistency of torque control.

[0078] By reducing the harmonic distortion rate of the three-phase current, the torque control accuracy is improved.

[0079] Step S3: Obtain motor position data, and obtain the electrical frequency based on the motor position data;

[0080] Specifically, the motor position is integrated to obtain the motor speed, and the electrical frequency is obtained after unit conversion.

[0081] In automotive applications, motor speeds have a wide dynamic range and load fluctuations are frequent. By converting the collected position signals into the electrical frequency fc required for phase compensation, key parameters are provided for hardware and software filtering and phase delay compensation, avoiding calculation errors in compensation due to unknown fc.

[0082] Step S4: Based on the electrical frequency and the optimal secondary filter coefficient, generate the phase delay compensation amount, and combine it with the motor position data to generate the compensated control angle.

[0083] Specifically, the rotational speed is first obtained by integrating the position data (θrecord) collected by the motor resolver, which is then converted into the electrical frequency (fc). The phase compensation amount (θf) is calculated by combining the hardware and software filtering parameters through a preset formula. Finally, the compensated control angle is generated by combining the motor position and the phase compensation amount.

[0084] Step S5: Input the three-phase current signal after secondary filtering into the conversion algorithm, and combine it with the compensated control angle to generate the compensated dq axis current feedback value.

[0085] Specifically, by converting the three-phase current after secondary filtering and combining it with the compensated control angle, the current feedback value of the dq axis is ensured to be consistent with the actual current state, thereby reducing the current deviation.

[0086] Step S6: Obtain the calibrated dq axis current command value;

[0087] The compensated dq-axis current feedback value and the calibrated dq-axis current command value are input into the PI controller for deviation adjustment. The adjustment result is converted into three-phase voltage by the three-phase inverter and output to control the permanent magnet synchronous motor.

[0088] Specifically, by combining the PI controller to adjust the deviation between the command value and the feedback value of the dq axis current, the torque output accuracy is further optimized; and by adapting to the rotor field-oriented vector control, the accuracy is improved without reducing the torque output capability.

[0089] Further analysis of the three-phase current signal after secondary filtering includes:

[0090] Real-time detection of harmonic components and the percentage of each harmonic amplitude in three-phase current;

[0091] Evaluate whether the three-phase current harmonic distortion rate meets the preset requirements;

[0092] The preset requirement is that the harmonic distortion rate of the three-phase current is less than a preset threshold.

[0093] When the three-phase current harmonic distortion rate drops below the preset threshold, the adjustment of the secondary filter coefficient is stopped, and the current coefficient is determined to be the optimal secondary filter coefficient.

[0094] Furthermore, the generation of phase delay compensation includes:

[0095] The motor speed is obtained by integrating the motor position, and the electrical frequency is obtained after unit conversion.

[0096] The phase compensation amount is obtained based on the electrical frequency and the optimal second-order filter coefficients.

[0097] The motor position and phase compensation amount are superimposed to generate the compensated control angle.

[0098] Furthermore, including:

[0099] The transformation algorithm is the Clark+Park coordinate transformation algorithm;

[0100] The three-phase current signal after secondary filtering is mapped to a stationary two-phase coordinate system using Clark transformation;

[0101] The Park transformation decouples the current signal in the stationary two-phase coordinate system to a rotating two-phase coordinate system synchronized with the rotor magnetic field. Combined with the compensated control angle, the compensated dq-axis current feedback value is generated.

[0102] Furthermore, including:

[0103] The calibrated dq axis current command value is obtained by decoupling the motor torque command through the maximum torque-current ratio;

[0104] The maximum torque-to-current ratio is the correspondence between the dq-axis current and the torque of the permanent magnet synchronous motor as determined by the test bench calibration.

[0105] Furthermore, including:

[0106] When the PI controller performs deviation adjustment, it optimizes the adjustment result by combining the real-time detected bus voltage value.

[0107] Furthermore, including:

[0108] Motor position data is acquired through a motor resolver. The electrical frequency is generated by integrating the acquired motor position data to obtain the motor speed, followed by unit conversion.

[0109] Specifically, by reducing the current harmonic distortion rate and compensating for phase delay, the deviation between the motor torque output and the command value is significantly reduced;

[0110] By optimizing the stability of the current signal, torque fluctuations caused by current fluctuations are reduced, thereby improving the overall driving comfort of the vehicle.

[0111] The solution is implemented entirely in software, allowing for zero-cost adaptation to existing electric drive systems for pure electric vehicles. Furthermore, through standardized parameter adjustment procedures, it can be adapted to different models of permanent magnet synchronous motors, making it suitable for a wide range of applications.

[0112] Figure 2 This is a structural diagram of a control system for improving the torque accuracy of a vehicle permanent magnet synchronous motor, provided by one or more embodiments of the present invention.

[0113] like Figure 2 As shown, it includes:

[0114] Hardware filtering module, secondary filtering module, filtering adjustment module, speed acquisition module, electrical frequency acquisition module, angle generation module, angle conversion module, current command value acquisition module, and deviation adjustment module;

[0115] The hardware filtering module is used to acquire the three-phase current signal of the permanent magnet synchronous motor and perform hardware filtering on the three-phase current signal of the permanent magnet synchronous motor.

[0116] The secondary filtering module is used to perform secondary filtering on the three-phase current signal after hardware filtering, obtain the secondary filtering coefficients, perform Fourier analysis on the three-phase current signal after secondary filtering, and evaluate whether the harmonic distortion rate of the three-phase current meets the preset requirements.

[0117] The filter adjustment module is used to determine the optimal secondary filter coefficient by adjusting the secondary filter coefficient and combining it with the three-phase current harmonic distortion rate.

[0118] The speed acquisition module is used to acquire motor position data and obtain the motor speed based on the motor position data.

[0119] The electrical frequency acquisition module is used to acquire the electrical frequency based on the motor speed.

[0120] An angle generation module is used to generate a phase delay compensation amount based on the electrical frequency, the optimal secondary filter coefficient, and the hardware filtering characteristics, and to generate a compensated control angle by combining the motor position data.

[0121] The angle conversion module is used to input the three-phase current data after secondary filtering into the conversion algorithm, and combine it with the compensated control angle to generate the compensated dq axis current feedback value.

[0122] The current command value acquisition module is used to acquire the calibrated dq axis current command value;

[0123] The deviation adjustment module is used to input the compensated dq axis current feedback value and the calibrated dq axis current command value into the PI controller for deviation adjustment. The adjustment result is converted into three-phase voltage by the three-phase inverter and output to control the permanent magnet synchronous motor.

[0124] It is worth noting that although only some basic functional modules are disclosed in this embodiment, it does not mean that the composition of this system is limited to the above-mentioned basic functional modules. On the contrary, what this embodiment intends to express is that, based on the above-mentioned basic functional modules, those skilled in the art can arbitrarily add one or more functional modules in combination with existing technology to form an infinite number of embodiments or technical solutions. That is to say, this system is open rather than closed. The fact that this embodiment only discloses a few basic functional modules does not mean that the scope of protection of the claims of this invention is limited to the disclosed basic functional modules. At the same time, for the convenience of description, the above device is described separately according to its functions as various units and modules. Of course, in implementing this invention, the functions of each unit and module can be implemented in one or more software and / or hardware.

[0125] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0126] Figure 3 This is a control block diagram of a permanent magnet synchronous motor provided in a specific embodiment of the present invention.

[0127] like Figure 3 As shown,

[0128] Rotor field-oriented vector control is adopted. The MTPA is the motor torque command, representing the relationship between the dq-axis current and the motor torque as specified in the bench calibration. , This is the commanded value for the dq axis current. , The actual dq-axis current value, PI represents the PI controller, and Udc represents the detected bus voltage value. , and The coordinate transformation method for converting three-phase current to dq-axis current is described, using Clark+Park to represent the coordinate transformation of three-phase current into dq-axis current. The description involves obtaining the dq-axis current command value after decoupling from the motor torque command, performing PI regulation with the current value fed back from the motor, and then transforming the result before inputting it to the three-phase inverter. The three-phase inverter outputs three-phase voltage to the permanent magnet synchronous motor, outputting three-phase current, which is then transformed to obtain the actual dq-axis current. The output is the change value of the PI controller. It employs rotor field-oriented vector control. `record` represents the motor position acquired by the motor resolver. Figure 4 The diagram shown is a control block diagram for improving motor torque accuracy. Figure 3 The difference is the addition of an angle correction module, with inputs record, f1, and f2, where f1 is the cutoff frequency of the hardware filtering module, f2 is the cutoff frequency of the software filtering module, record is the motor position acquired by the motor resolver, and the output is composed, which is the compensated output applied to motor control. Figure 5 For the angle correction module, the record is integrated to obtain the motor speed, and then the unit is converted to obtain fc, which is the motor's electrical frequency. This fc is calculated using formulas 1-6 with the software and hardware filters to obtain f. This fc is then summed with the motor position to compensate for the current phase deviation caused by the filters, preventing steady-state error in the output torque. Figure 4 The diagram shows the software filter parameter adjustment block diagram. The three-phase current undergoes hardware filtering followed by software filtering. The filter parameters are shown in Formulas 1 and 2, while Formulas 3 to 6 represent the delay caused by filtering. The software filter parameters are adjusted, and Fourier analysis is performed on the three-phase current until suitable software filter parameters are obtained. Figure 6 The control flow is shown.

[0129] in,

[0130] (1)

[0131] (2)

[0132] (3)

[0133] (4)

[0134] (5)

[0135] (6)

[0136] Figure 7 The present invention provides an electronic device structural block diagram of a control method for improving the torque accuracy of a vehicle permanent magnet synchronous motor, according to one or more embodiments.

[0137] like Figure 7 This application provides an electronic device, including: a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

[0138] The memory stores a computer program, which, when executed by the processor, causes the processor to perform steps of a control method to improve the torque accuracy of a vehicle permanent magnet synchronous motor.

[0139] This application also provides a computer-readable storage medium storing a computer program executable by an electronic device, which, when run on the electronic device, causes the electronic device to perform steps of a control method for improving the torque accuracy of a vehicle permanent magnet synchronous motor.

[0140] For the sake of simplicity, the method embodiments are described as a series of actions. However, those skilled in the art should understand that the embodiments of the present invention are not limited to the described order of actions, because according to the embodiments of the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions involved are not necessarily essential to the embodiments of the present invention.

[0141] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of this application.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control method for improving the torque accuracy of a vehicle permanent magnet synchronous motor, characterized in that, Includes the following steps: The three-phase current signal after hardware filtering is subjected to secondary filtering to obtain the secondary filtering coefficients. The three-phase current signal after secondary filtering is analyzed to obtain the three-phase current harmonic distortion rate. The optimal secondary filter coefficient is determined by adjusting the secondary filter coefficient and combining it with the three-phase current harmonic distortion rate. Obtain motor position data, and obtain the electrical frequency based on the motor position data; Based on the electrical frequency and the optimal secondary filter coefficient, a phase delay compensation amount is generated, and combined with the motor position data, a compensated control angle is generated. The three-phase current signal after secondary filtering is input into the conversion algorithm, and combined with the compensated control angle, the compensated dq-axis current feedback value is generated. Obtain the calibrated dq axis current command value; The compensated dq-axis current feedback value and the calibrated dq-axis current command value are input into the PI controller for deviation adjustment. The adjustment result is converted into three-phase voltage by the three-phase inverter and output to control the permanent magnet synchronous motor.

2. The control method for improving the torque accuracy of a vehicle permanent magnet synchronous motor according to claim 1, characterized in that, The analysis of the three-phase current signal after secondary filtering includes: Real-time detection of harmonic components and the percentage of each harmonic amplitude in three-phase current; Evaluate whether the three-phase current harmonic distortion rate meets the preset requirements; The preset requirement is that the harmonic distortion rate of the three-phase current is less than a preset threshold. When the three-phase current harmonic distortion rate drops below the preset threshold, the adjustment of the secondary filter coefficient is stopped, and the current coefficient is determined to be the optimal secondary filter coefficient.

3. The control method for improving the torque accuracy of a vehicle permanent magnet synchronous motor according to claim 1, characterized in that, The generated phase delay compensation includes: The motor speed is obtained by integrating the motor position, and the electrical frequency is obtained after unit conversion. Based on the electrical frequency and the optimal secondary filter coefficients, the phase compensation amount is obtained; The motor position is superimposed with the phase compensation amount to generate the compensated control angle.

4. The control method for improving the torque accuracy of a vehicle permanent magnet synchronous motor according to claim 1, characterized in that, The transformation algorithm is the Clark+Park coordinate transformation algorithm; The three-phase current signal after secondary filtering is mapped to a stationary two-phase coordinate system using Clark transformation; The Park transformation decouples the current signal in the stationary two-phase coordinate system to a rotating two-phase coordinate system synchronized with the rotor magnetic field, and then, in combination with the compensated control angle, generates the compensated dq-axis current feedback value.

5. The control method for improving the torque accuracy of a vehicle permanent magnet synchronous motor according to claim 1, characterized in that, The calibrated dq axis current command value is obtained by decoupling the motor torque command through the maximum torque-current ratio. The maximum torque-to-current ratio is the correspondence between the dq-axis current and the torque of the permanent magnet synchronous motor as determined by the test bench calibration.

6. The control method for improving the torque accuracy of a vehicle permanent magnet synchronous motor according to claim 1, characterized in that, When the PI controller performs deviation adjustment, it optimizes the adjustment result by combining the real-time detected bus voltage value.

7. The control method for improving the torque accuracy of a vehicle permanent magnet synchronous motor according to claim 1, characterized in that, The motor position data is acquired through a motor resolver, and the electrical frequency is generated by integrating the acquired motor position data to obtain the motor speed and then converting the values ​​to units.

8. A control system for improving the torque accuracy of a vehicle permanent magnet synchronous motor, characterized in that, include: Hardware filtering module, secondary filtering module, filtering adjustment module, speed acquisition module, electrical frequency acquisition module, angle generation module, angle conversion module, current command value acquisition module, and deviation adjustment module; The hardware filtering module is used to acquire the three-phase current signal of the permanent magnet synchronous motor and perform hardware filtering processing on the three-phase current signal of the permanent magnet synchronous motor. The secondary filtering module is used to perform secondary filtering on the three-phase current signal after hardware filtering, obtain the secondary filtering coefficients, perform Fourier analysis on the three-phase current signal after secondary filtering, and evaluate whether the harmonic distortion rate of the three-phase current meets the preset requirements. The filter adjustment module is used to determine the optimal secondary filter coefficient by adjusting the secondary filter coefficient and combining it with the harmonic distortion rate of the three-phase current. The speed acquisition module is used to acquire motor position data and acquire motor speed based on the motor position data; The electrical frequency acquisition module is used to acquire the electrical frequency based on the motor speed. An angle generation module is used to generate a phase delay compensation amount based on the electrical frequency, the optimal secondary filter coefficient, and the hardware filtering characteristics, and to generate a compensated control angle by combining the motor position data. The angle conversion module is used to input the three-phase current data after secondary filtering into the conversion algorithm, and combine it with the compensated control angle to generate the compensated dq axis current feedback value. The current command value acquisition module is used to acquire the calibrated dq axis current command value; The deviation adjustment module is used to input the compensated dq-axis current feedback value and the calibrated dq-axis current command value into the PI controller for deviation adjustment, and convert the adjustment result into three-phase voltage through the three-phase inverter to control the permanent magnet synchronous motor.

9. An electronic device, characterized in that, include: The processor, communication interface, memory, and communication bus are connected, with the processor, communication interface, and memory communicating with each other via the communication bus. The memory stores a computer program, which, when executed by the processor, causes the processor to perform the steps of the control method for improving the torque accuracy of a vehicle permanent magnet synchronous motor as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, It stores a computer program executable by an electronic device, which, when run on the electronic device, causes the electronic device to perform the steps of a control method for improving the torque accuracy of a vehicle permanent magnet synchronous motor as described in any one of claims 1-7.

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