A method and system for harmonic injection self-calibration of permanent magnet synchronous motor

Abstract

This invention discloses a method and system for harmonic injection self-calibration of a permanent magnet synchronous motor. The method includes: a host computer acquiring 24th-order and 48th-order noise values ​​corresponding to each operating condition point of the permanent magnet synchronous motor under rated voltage and multiple preset torque percentages and speed ranges, collected by an NVH noise testing device, and identifying operating conditions exceeding preset thresholds as operating conditions to be optimized; for each operating condition to be optimized, the host computer controls the motor controller to output a preset initial value of harmonic current, and while keeping the initial value of harmonic current unchanged, successively changes the harmonic injection angle by a step angle, obtaining a first noise value group consisting of the first noise values ​​corresponding to each harmonic injection angle, and determining the harmonic injection angle corresponding to the smallest first noise value in the first noise value group as the optimal angle. The method and system of this application realize fully automatic and objective calibration of harmonic injection parameters, with high calibration efficiency and good consistency.

Description

Technical Field

[0001] This invention relates to the field of permanent magnet synchronous motor control technology, and in particular to a method and system for harmonic injection self-calibration of a permanent magnet synchronous motor. Background Technology

[0002] Permanent magnet synchronous motors (PMSMs) are widely used in new energy vehicles, industrial servo systems, and other fields due to their high power density and high efficiency. However, during operation, PMSMs generate torque pulsations and electromagnetic force waves of specific orders due to inverter nonlinearity, cogging torque, and rotor flux harmonics, which in turn cause vibration and noise problems. Among these, the 24th and 48th order noises are the main order components affecting the motor's NVH performance.

[0003] To suppress the aforementioned order noise, the current mainstream technique is harmonic current injection. Its basic principle is to inject harmonic current with a specific amplitude and phase into the current loop of the motor controller, generating a compensating torque with the same amplitude but opposite phase to the original pulsating torque. This cancels out the torque pulsation of a specific order, reducing noise. The effectiveness of harmonic current injection depends on the selection of two parameters: the amplitude and angle of the injected current. The optimal values ​​of these two parameters vary depending on the motor's speed and torque operating conditions. Therefore, calibration is required for different operating points to create a harmonic injection parameter MAP table covering commonly used operating areas.

[0004] Currently, existing methods for calibrating harmonic injection parameters mainly employ the optimal angle calibration method for harmonic current, and this is largely done manually. The basic process involves the calibration personnel manually adjusting the angle and amplitude of the harmonic injection current on a dynamometer bench, targeting the operating point where NVH optimization is needed. Simultaneously, they judge the noise change trend using their ear or a simple sound level meter, and after repeated trials, select the parameter combination that they subjectively consider to have the lowest noise. This method has the following significant drawbacks: First, the calibration efficiency is extremely low. Since the angle and current amplitude constitute a two-dimensional search space, the calibration personnel need to try repeatedly in both dimensions. Moreover, after each parameter adjustment, they need to wait for the motor to run stably and judge the effect by sound. A complete 24th and 48th order parameter matrix often takes several days or even weeks to complete, which consumes a lot of manpower and material resources.

[0005] Second, calibration results depend on the experience and skill level of the calibration personnel. Different calibration personnel may have different subjective perceptions of noise levels, and even the same calibration personnel may make inconsistent judgments at different times due to factors such as fatigue and environmental noise interference. This results in poor consistency of calibration results, making it difficult to guarantee finding the globally optimal parameter combination and affecting the consistency of the vehicle's NVH performance.

[0006] Third, manual listening judgment is difficult to guarantee accuracy; the human ear has limited sensitivity to changes in noise, especially when the noise reduction is small, it is difficult to accurately distinguish changes in noise value, and it is easy to miss the optimal parameter combination, which reduces the reliability of calibration results.

[0007] In summary, existing methods for calibrating harmonic injection parameters of permanent magnet synchronous motors suffer from drawbacks such as low efficiency, poor consistency, excessive reliance on human experience, and difficulty in guaranteeing calibration accuracy. There is an urgent need for a harmonic injection parameter calibration scheme that can achieve automation, objectivity, high efficiency, and high consistency. Summary of the Invention

[0008] To address the technical problems existing in the background art, this invention proposes a method and system for harmonic injection self-calibration of a permanent magnet synchronous motor.

[0009] This invention proposes a method for harmonic injection self-calibration of a permanent magnet synchronous motor, applied to a test system consisting of a host computer, a motor controller, a permanent magnet synchronous motor, and NVH noise testing equipment, comprising: When the host computer acquires the dynamic operating conditions of the permanent magnet synchronous motor running under rated voltage with multiple preset torque percentages and speed ranges, the NVH noise testing equipment collects the 24th-order noise value and 48th-order noise value corresponding to each operating condition point, and the operating condition points where the 24th-order noise value and 48th-order noise value exceed the preset threshold are identified as operating condition points to be optimized. For each operating condition to be optimized, the host computer controls the motor controller to output a preset initial value of harmonic current. While keeping the initial value of harmonic current unchanged, the harmonic injection angle is changed step by step according to the first step angle. The first noise value collected by the NVH noise test equipment under each changed harmonic injection angle is obtained, and a first noise value group is obtained by the first noise value corresponding to each harmonic injection angle. The harmonic injection angle corresponding to the smallest first noise value in the first noise value group is determined as the optimal angle. The host computer controls the motor controller to change the harmonic current amplitude one step at the optimal angle, and obtains the second noise value collected by the NVH noise test equipment under the harmonic current amplitude after each change. The second noise value group is composed of the second noise values ​​corresponding to each harmonic current amplitude. The harmonic current amplitude corresponding to the smallest second noise value in the second noise value group is determined as the optimal current value. The host computer writes the optimal angle and optimal current value as harmonic injection parameters for the operating condition to be optimized into the parameter table of the motor controller, so as to realize the self-calibration of harmonic injection for the operating condition to be optimized.

[0010] Preferably, the plurality of preset torque percentages include 100% peak torque, 80% peak torque, 60% peak torque, 40% peak torque, 20% peak torque, -20% peak torque, and -40% peak torque; in dynamic operating conditions, for each torque percentage, the host computer controls the permanent magnet synchronous motor to increase the load speed from the preset starting speed to the peak speed.

[0011] Preferably, the initial value of the harmonic current is in the range of 0-10 amperes, the first step angle is in the range of 0-20 degrees, and the harmonic injection angle is in the range of 0 degrees to 360 degrees.

[0012] Preferably, the value range of the first step current is 0-0.5 amperes, and the range of harmonic current amplitude variation is from zero amperes to the preset maximum harmonic current value.

[0013] Preferably, when the host computer changes the harmonic injection angle successively, it simultaneously collects and saves the first noise value, motor speed and torque data corresponding to each changed harmonic injection angle; and when the harmonic current amplitude is changed successively, it simultaneously collects and saves the second noise value, motor speed and torque data corresponding to each changed harmonic current amplitude.

[0014] Preferably, the host computer communicates with the motor controller and the NVH noise testing equipment via the CAN bus to obtain motor speed, motor temperature, controller temperature and fault codes.

[0015] Preferably, the method further includes: after the host computer writes the harmonic injection parameters into the motor controller, it controls the permanent magnet synchronous motor to run to the operating point to be optimized, and obtains the noise signal after injection to confirm the improvement of NVH performance.

[0016] Preferably, when the injected noise signal does not reach the preset improvement target, the host computer performs a second scan optimization with a second step angle and a second step current, wherein the second step angle is smaller than the first step angle and the second step current is smaller than the first step current.

[0017] This invention proposes a harmonic injection self-calibration system for a permanent magnet synchronous motor, comprising a host computer, a motor controller, a permanent magnet synchronous motor, and an NVH noise testing device. The host computer is connected to the motor controller and the NVH noise testing device via a communication bus. The host computer includes: The dynamic operating condition control module is used to control the motor controller to drive the permanent magnet synchronous motor to operate under multiple preset torque percentages and speed ranges under rated voltage. The noise acquisition module is used to acquire the 24th-order and 48th-order noise values ​​corresponding to each operating point collected by the NVH noise testing equipment under dynamic operating conditions. The operating point identification module is used to compare the 24th-order noise value and the 48th-order noise value obtained by the noise acquisition module with preset thresholds respectively, and to identify the operating points that exceed the preset thresholds as operating points to be optimized. The angle optimization module is used to control the motor controller to output a preset initial value of harmonic current for each operating condition point to be optimized, and to change the harmonic injection angle successively according to the preset first step angle. The noise acquisition module obtains the first noise value corresponding to each changed harmonic injection angle, and obtains a first noise value group composed of the first noise values ​​corresponding to each harmonic injection angle. The harmonic injection angle corresponding to the smallest first noise value in the first noise value group is determined as the optimal angle. The current optimization module is used to control the motor controller to change the harmonic current amplitude successively according to the preset first step current at the optimal angle. The noise acquisition module obtains the second noise value corresponding to the harmonic current amplitude after each change, and obtains a second noise value group composed of the second noise values ​​corresponding to each harmonic current amplitude. The harmonic current amplitude corresponding to the smallest second noise value in the second noise value group is determined as the optimal current value. The parameter writing module is used to write the optimal angle and optimal current value as harmonic injection parameters for the operating condition to be optimized into the parameter table of the motor controller, so as to realize the harmonic injection self-calibration for the operating condition to be optimized.

[0018] Preferably, the plurality of preset torque percentages include 100% peak torque, 80% peak torque, 60% peak torque, 40% peak torque, 20% peak torque, -20% peak torque, and -40% peak torque; in dynamic operating conditions, the dynamic operating condition control module controls the permanent magnet synchronous motor to increase the load speed from the preset starting speed to the peak speed.

[0019] The proposed method and system for harmonic injection self-calibration of permanent magnet synchronous motors utilizes a closed-loop testing system comprised of a host computer, a motor controller, and NVH noise testing equipment. This system enables automatic execution of dynamic frequency sweeping under multiple torque conditions and objective identification of the operating point to be optimized, replacing manual experience-based judgment and avoiding calibration deviations and omissions caused by human factors. A step-by-step decoupled optimization strategy is employed: first, the initial value of the harmonic current is fixed while scanning the harmonic injection angle to determine the optimal angle; then, the optimal angle is fixed while scanning the harmonic current amplitude to determine the optimal current value. This transforms the highly complex search in the two-dimensional parameter space into two one-dimensional ordered scanning processes, reliably approximating the globally optimal parameter combination within a finite number of steps, thus ensuring both calibration accuracy and efficiency. The entire calibration process uses the objective noise decibel value collected by the NVH noise testing equipment as the sole evaluation criterion, eliminating the influence of subjective hearing differences on the consistency of calibration results and ensuring the high repeatability of parameters obtained from different motors and different batches. Finally, the calibration parameters are automatically written into the motor controller and verified, forming a complete automated closed loop of calibration, writing, and verification, which reduces manpower and time costs. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating the process of a harmonic injection self-calibration method for a permanent magnet synchronous motor proposed in this invention. Figure 2 This is a flowchart illustrating the automated search for 24th / 48th order optimized operating points in one embodiment of a method for harmonic injection self-calibration of a permanent magnet synchronous motor proposed in this invention. Figure 3 This is a flowchart illustrating the automatic calibration of harmonic current in one embodiment of a method for harmonic injection self-calibration of a permanent magnet synchronous motor proposed in this invention. Figure 4 This is a schematic diagram of the system architecture of a harmonic injection self-calibration system for a permanent magnet synchronous motor proposed in this invention. Detailed Implementation

[0021] Reference Figures 1-3 This invention proposes a method for harmonic injection self-calibration of a permanent magnet synchronous motor, applied to a test system consisting of a host computer, a motor controller, a permanent magnet synchronous motor, and NVH noise testing equipment, comprising the following steps: S1. When the host computer obtains the dynamic operating conditions of the permanent magnet synchronous motor under rated voltage with multiple preset torque percentages and speed ranges, the NVH noise test equipment collects the 24th and 48th noise values ​​corresponding to each operating point, and determines the operating points where the 24th and 48th noise values ​​exceed the preset thresholds as operating points to be optimized.

[0022] It should be noted that the host computer, as the control core of the entire calibration process, communicates with both the motor controller and the NVH noise testing equipment via a CAN bus. The NVH noise testing equipment can be a precision sound level meter or a multi-channel vibration and noise acquisition and analysis instrument, which interacts with the host computer via a CAN or Ethernet interface, transmitting data such as noise sound pressure level and order analysis results to the host computer in real time.

[0023] In this embodiment, the preset torque percentages include 100% peak torque, 80% peak torque, 60% peak torque, 40% peak torque, 20% peak torque, -20% peak torque, and -40% peak torque. In dynamic operating conditions, for each torque percentage, the host computer controls the permanent magnet synchronous motor to increase the load speed from the preset starting speed to the peak speed.

[0024] Specifically, for each torque percentage, the host computer controls the motor to run stably under load from a preset starting speed (e.g., 100 rpm), and then linearly increases to the peak speed, completing a frequency sweep across the entire speed range at that torque level. The starting speed for sweeping at 100% peak torque can be set to 100 rpm, and the starting speed for sweeping at other torque percentages can be set to 500 rpm or other appropriate values, which should be selected by those skilled in the art based on the motor characteristics.

[0025] like Figure 2 As shown, the NVH dynamic test is performed with a given peak torque Trqmax, increasing the speed from 100 rpm to the peak torque and speed. The NVH dynamic test is also performed with a given peak torque of 80%, increasing the speed from 500 rpm to the peak torque and speed. Similarly, NVH dynamic tests are performed with peak torques of 60%, 40%, 20%, -20%, and -40% Trqmax. Figure 2 In this context, Sqdmax represents the maximum rotational speed, and Noisemax represents the noise threshold.

[0026] In this embodiment, the initial value of the harmonic current ranges from 0 to 10 amperes, the first step angle ranges from 0 to 20 degrees, and the harmonic injection angle ranges from 0 to 360 degrees. The first step current ranges from 0 to 0.5 amperes, and the harmonic current amplitude ranges from zero amperes to a preset maximum harmonic current value.

[0027] S2. For each operating condition to be optimized, the host computer controls the motor controller to output a preset initial value of harmonic current. While keeping the initial value of harmonic current unchanged, the harmonic injection angle is changed step by step according to the first step angle. The first noise value collected by the NVH noise test equipment under each changed harmonic injection angle is obtained, and a first noise value group is obtained, which is composed of the first noise values ​​corresponding to each harmonic injection angle. The harmonic injection angle corresponding to the smallest first noise value in the first noise value group is determined as the optimal angle.

[0028] S3. The host computer controls the motor controller to change the harmonic current amplitude one step at the optimal angle, and obtains the second noise value collected by the NVH noise test equipment under the harmonic current amplitude after each change. The second noise value group is composed of the second noise values ​​corresponding to each harmonic current amplitude. The harmonic current amplitude corresponding to the smallest second noise value in the second noise value group is determined as the optimal current value.

[0029] Specifically, when the host computer changes the harmonic injection angle one by one, it simultaneously collects and saves the first noise value, motor speed and torque data corresponding to each changed harmonic injection angle; and when the harmonic current amplitude changes one by one, it simultaneously collects and saves the second noise value, motor speed and torque data corresponding to each changed harmonic current amplitude.

[0030] In this embodiment, the host computer communicates with the motor controller and the NVH noise testing equipment via the CAN bus to obtain motor speed, motor temperature, controller temperature and fault codes.

[0031] Specifically, taking a specific operating condition to be optimized, "2000 rpm @ 50 Nm, 24th order," as an example, the host computer enters the self-calibration process for this operating condition. First, it controls the motor controller to ensure the motor operates stably at the optimized operating condition, sending a command to the motor controller to output the preset initial value of the harmonic current. For the 24th order optimized operating condition, such as... Figure 3As shown, the initial value of the harmonic current, CAL_IsInit, is set to 2 amps; the initial value of the harmonic angle, CAL_AgInit, is 0°; Ismax is the maximum harmonic calibration current value; Agmax is the maximum harmonic calibration angle; the harmonic current step size is I, and the angle step size is The; Ag_ref is the harmonic injection angle; Is_ref is the harmonic injection current. While keeping the initial harmonic current value of 2 amps constant, the harmonic injection angle is changed sequentially in increments of 5 degrees. The range of the harmonic injection angle is from 0 degrees to 360 degrees, i.e., outputting 0 degrees, 5 degrees, 10 degrees…355 degrees sequentially. At each harmonic injection angle, the first noise value collected by the NVH noise testing equipment is acquired, and this first noise value and its corresponding harmonic injection angle are recorded. After traversing all angles, a first noise value group is obtained, consisting of the first noise values ​​corresponding to each harmonic injection angle. The harmonic injection angle corresponding to the smallest first noise value in the first noise value group is determined as the optimal angle. For example, if the noise decreases the most and the noise value is the smallest at a certain angle, then that angle is the 24th order optimal angle for the operating condition to be optimized.

[0032] Subsequently, at the determined optimal angle, the motor controller is used to successively change the harmonic current amplitude by an initial step current of 0.5 amps. The range of harmonic current amplitude changes is from zero amps to a preset maximum harmonic current value (e.g., 15 amps). At each harmonic current amplitude, a second noise value is acquired using NVH noise testing equipment, and this second noise value and its corresponding harmonic current amplitude are recorded. After traversing all current amplitudes, a second noise value group is obtained, consisting of the second noise values ​​corresponding to each harmonic current amplitude. The harmonic current amplitude corresponding to the smallest second noise value in the second noise value group is determined as the optimal current value. At this point, the calibration of the 24th order harmonic injection parameters (optimal angle and optimal current value) for the operating condition to be optimized is complete.

[0033] S4. The host computer writes the optimal angle and optimal current value as harmonic injection parameters for the operating point to be optimized into the parameter table of the motor controller, so as to realize the self-calibration of harmonic injection for the operating point to be optimized.

[0034] In this embodiment, the method further includes: after the host computer writes the harmonic injection parameters into the motor controller, it controls the permanent magnet synchronous motor to run to the operating point to be optimized, and obtains the noise signal after injection to confirm the improvement of NVH performance.

[0035] In this embodiment, when the injected noise signal does not reach the preset improvement target, the host computer performs a second scan optimization with a second step angle and a second step current, wherein the second step angle is smaller than the first step angle and the second step current is smaller than the first step current.

[0036] Reference Figure 4This invention proposes a system for harmonic injection self-calibration of a permanent magnet synchronous motor, comprising a host computer, a motor controller, a permanent magnet synchronous motor, and an NVH noise testing device. The host computer is connected to the motor controller and the NVH noise testing device via a communication bus. The host computer includes: The dynamic operating condition control module is used to control the motor controller to drive the permanent magnet synchronous motor to operate under multiple preset torque percentages and speed ranges under rated voltage. The noise acquisition module is used to acquire the 24th-order and 48th-order noise values ​​corresponding to each operating point collected by the NVH noise testing equipment under dynamic operating conditions. The operating point identification module is used to compare the 24th-order noise value and the 48th-order noise value obtained by the noise acquisition module with preset thresholds respectively, and to identify the operating points that exceed the preset thresholds as operating points to be optimized. The angle optimization module is used to control the motor controller to output a preset initial value of harmonic current for each operating condition point to be optimized, and to change the harmonic injection angle successively according to the preset first step angle. The noise acquisition module obtains the first noise value corresponding to each changed harmonic injection angle, and obtains a first noise value group composed of the first noise values ​​corresponding to each harmonic injection angle. The harmonic injection angle corresponding to the smallest first noise value in the first noise value group is determined as the optimal angle. The current optimization module is used to control the motor controller to change the harmonic current amplitude successively according to the preset first step current at the optimal angle. The noise acquisition module obtains the second noise value corresponding to the harmonic current amplitude after each change, and obtains a second noise value group composed of the second noise values ​​corresponding to each harmonic current amplitude. The harmonic current amplitude corresponding to the smallest second noise value in the second noise value group is determined as the optimal current value. The parameter writing module is used to write the optimal angle and optimal current value as harmonic injection parameters for the operating condition to be optimized into the parameter table of the motor controller, so as to realize the harmonic injection self-calibration for the operating condition to be optimized.

[0037] In this embodiment, multiple preset torque percentages include 100% peak torque, 80% peak torque, 60% peak torque, 40% peak torque, 20% peak torque, -20% peak torque, and -40% peak torque; in dynamic operating conditions, the dynamic operating condition control module controls the permanent magnet synchronous motor to increase the load speed from the preset starting speed to the peak speed.

[0038] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for harmonic injection self-calibration of a permanent magnet synchronous motor, applied to a test system consisting of a host computer, a motor controller, a permanent magnet synchronous motor, and NVH noise testing equipment, characterized in that... include: When the host computer acquires the dynamic operating conditions of the permanent magnet synchronous motor running under rated voltage with multiple preset torque percentages and speed ranges, the NVH noise testing equipment collects the 24th-order noise value and 48th-order noise value corresponding to each operating condition point, and the operating condition points where the 24th-order noise value and 48th-order noise value exceed the preset threshold are identified as operating condition points to be optimized. For each operating condition to be optimized, the host computer controls the motor controller to output a preset initial value of harmonic current. While keeping the initial value of harmonic current unchanged, the harmonic injection angle is changed step by step according to the first step angle. The first noise value collected by the NVH noise test equipment under each changed harmonic injection angle is obtained, and a first noise value group is obtained by the first noise value corresponding to each harmonic injection angle. The harmonic injection angle corresponding to the smallest first noise value in the first noise value group is determined as the optimal angle. The host computer controls the motor controller to change the harmonic current amplitude one step at the optimal angle, and obtains the second noise value collected by the NVH noise test equipment under the harmonic current amplitude after each change. The second noise value group is composed of the second noise values ​​corresponding to each harmonic current amplitude. The harmonic current amplitude corresponding to the smallest second noise value in the second noise value group is determined as the optimal current value. The host computer writes the optimal angle and optimal current value as harmonic injection parameters for the operating condition to be optimized into the parameter table of the motor controller, so as to realize the self-calibration of harmonic injection for the operating condition to be optimized.

2. The method for harmonic injection self-calibration of a permanent magnet synchronous motor according to claim 1, characterized in that, The preset torque percentages include 100% peak torque, 80% peak torque, 60% peak torque, 40% peak torque, 20% peak torque, -20% peak torque, and -40% peak torque. In dynamic operating conditions, for each torque percentage, the host computer controls the permanent magnet synchronous motor to increase the load speed from the preset starting speed to the peak speed.

3. The method for harmonic injection self-calibration of a permanent magnet synchronous motor according to claim 1, characterized in that, The initial value of the harmonic current ranges from 0 to 10 amperes, the first step angle ranges from 0 to 20 degrees, and the harmonic injection angle ranges from 0 to 360 degrees.

4. The method for harmonic injection self-calibration of a permanent magnet synchronous motor according to claim 1, characterized in that, The value range of the first step current is 0-0.5 amperes, and the range of harmonic current amplitude variation is from zero amperes to the preset maximum harmonic current value.

5. The method for harmonic injection self-calibration of a permanent magnet synchronous motor according to claim 1, characterized in that, As the host computer changes the harmonic injection angle one by one, it simultaneously collects and saves the first noise value, motor speed and torque data corresponding to each changed harmonic injection angle. And while changing the harmonic current amplitude one by one, the second noise value, motor speed and torque data corresponding to the harmonic current amplitude after each change are collected and saved simultaneously.

6. The method for harmonic injection self-calibration of a permanent magnet synchronous motor according to claim 1, characterized in that, The host computer communicates with the motor controller and the NVH noise testing equipment via the CAN bus to obtain motor speed, motor temperature, controller temperature and fault codes.

7. The method for harmonic injection self-calibration of a permanent magnet synchronous motor according to any one of claims 1 to 6, characterized in that, The method further includes: after the host computer writes the harmonic injection parameters into the motor controller, it controls the permanent magnet synchronous motor to run to the operating point to be optimized, and obtains the noise signal after injection to confirm the improvement of NVH performance.

8. The method for harmonic injection self-calibration of a permanent magnet synchronous motor according to claim 7, characterized in that, When the injected noise signal does not reach the preset improvement target, the host computer performs a second scan optimization with a second step angle and a second step current, wherein the second step angle is smaller than the first step angle and the second step current is smaller than the first step current.

9. A system for harmonic injection self-calibration of a permanent magnet synchronous motor, comprising a host computer, a motor controller, a permanent magnet synchronous motor, and an NVH noise testing device, wherein the host computer is connected to the motor controller and the NVH noise testing device respectively via a communication bus, characterized in that... The host computer includes: The dynamic operating condition control module is used to control the motor controller to drive the permanent magnet synchronous motor to operate under multiple preset torque percentages and speed ranges under rated voltage. The noise acquisition module is used to acquire the 24th-order and 48th-order noise values ​​corresponding to each operating point collected by the NVH noise testing equipment under dynamic operating conditions. The operating point identification module is used to compare the 24th-order noise value and the 48th-order noise value obtained by the noise acquisition module with preset thresholds respectively, and to identify the operating points that exceed the preset thresholds as operating points to be optimized. The angle optimization module is used to control the motor controller to output a preset initial value of harmonic current for each operating condition point to be optimized, and to change the harmonic injection angle successively according to the preset first step angle. The noise acquisition module obtains the first noise value corresponding to each changed harmonic injection angle, and obtains a first noise value group composed of the first noise values ​​corresponding to each harmonic injection angle. The harmonic injection angle corresponding to the smallest first noise value in the first noise value group is determined as the optimal angle. The current optimization module is used to control the motor controller to change the harmonic current amplitude successively according to the preset first step current at the optimal angle. The noise acquisition module obtains the second noise value corresponding to the harmonic current amplitude after each change, and obtains a second noise value group composed of the second noise values ​​corresponding to each harmonic current amplitude. The harmonic current amplitude corresponding to the smallest second noise value in the second noise value group is determined as the optimal current value. The parameter writing module is used to write the optimal angle and optimal current value as harmonic injection parameters for the operating condition to be optimized into the parameter table of the motor controller, so as to realize the harmonic injection self-calibration for the operating condition to be optimized.

10. The system for harmonic injection self-calibration of a permanent magnet synchronous motor according to claim 9, characterized in that, The preset torque percentages include 100% peak torque, 80% peak torque, 60% peak torque, 40% peak torque, 20% peak torque, -20% peak torque, and -40% peak torque; in dynamic operating conditions, the dynamic operating condition control module controls the permanent magnet synchronous motor to increase the load speed from the preset starting speed to the peak speed.

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