Harmonic injection method, controller and electric compressor

Abstract

The present application relates to a harmonic injection method, a controller and an electric compressor, and belongs to the field of motor control technology. The method comprises: obtaining control parameters to be input into the electric compressor; inputting the control parameters into a pre-constructed compressor vibration model, so as to receive the control parameters to be input through an input unit in the compressor vibration model, filtering out invalid control parameters through a filtering unit in the compressor vibration model, and calculating and outputting an injection voltage according to the control parameters and NVH results corresponding to the control parameters through a calculation unit in the compressor vibration model; correcting the injection voltage through a correction unit in the compressor vibration model to obtain an optimal injection voltage; the correction unit is used to correct the injection voltage when the electric compressor is replaced; the injection voltage can be corrected after the electric compressor is structurally adjusted, without the need for large-scale experiments, and the debugging efficiency of the compressor can be improved.

Description

Technical Field

[0001] The present application relates to a harmonic injection method, a controller and an electric compressor, and belongs to the technical field of motor control. Background Art

[0002] As the requirements for the power of electric vehicles continue to increase, automotive permanent magnet synchronous motors are also developing towards high power and high torque. The vibration and noise of permanent magnet synchronous motors are also increasing, which will greatly affect the comfort of the passengers in the car. At the same time, the vibration problem of permanent magnet synchronous motors will cause the permanent magnets of the motors to lose magnetism, causing safety hazards in the car, and further affecting the safety of the passengers in the car. Therefore, it is necessary to explore effective methods to suppress vibration and noise, and reduce the vibration and noise of automotive permanent magnet synchronous motors during operation.

[0003] Electromagnetic noise refers to the vibration caused by the electromagnetic force during the operation of the motor, which is transmitted through the motor itself to the surrounding space, causing the vibration of particles in the air and causing sound waves. When the frequency of the sound wave is in the range of 20 Hz to 20 kHz, electromagnetic noise can be felt by the human ear.

[0004] At present, the harmonic injection method is usually used to suppress the electromagnetic noise generated by the motor. Harmonics refer to periodic fluctuation signals whose frequency is an integer multiple of the fundamental frequency. Harmonic injection means: injecting a harmonic injection energy into the motor that is the same as the energy corresponding to the electromagnetic noise generated by the motor, so that the two energies can cancel each other out, thereby achieving the effect of noise reduction.

[0005] Traditional harmonic injection methods generally calculate the voltage to be injected based on a specific electric compressor. If a new electric compressor is replaced, the original calculation method is no longer applicable and the calculation model needs to be re-determined to calculate the voltage to be injected. Summary of the invention

[0006] The present application provides a harmonic injection method, device and storage medium, which can solve the problem that the calculation model of harmonic injection voltage needs to be rebuilt when replacing an electric compressor, and the harmonic injection efficiency is low. The present application provides the following technical solutions:

[0007] In a first aspect, a harmonic injection method is provided, the method comprising:

[0008] acquiring control parameters to be input into the electric compressor;

[0009] The control parameters are input into a pre-constructed compressor vibration model, so that after the input unit in the compressor vibration model receives the control parameters to be input, the filtering unit in the compressor vibration model filters out invalid control parameters, and the calculation unit in the compressor vibration model calculates and outputs an injection voltage according to the control parameters and the NVH results corresponding to the control parameters; the correction unit in the compressor vibration model corrects the injection voltage to obtain an optimal injection voltage; the correction unit is used to correct the injection voltage when the electric compressor is replaced.

[0010] Optionally, the calculation unit calculates and outputs the injection voltage according to the control parameter and the NVH result corresponding to the control parameter, including:

[0011] Obtaining NVH data corresponding to the electric compressor under different control parameters, and screening out target control parameters whose NVH data meet preset requirements;

[0012] Determining a test point for harmonic injection based on the target control parameter;

[0013] For each test point, use at least one harmonic component of a preset order frequency, scan different phase angles at fixed intervals within the range of 0 to 2π to perform harmonic voltage injection, and observe the NVH results output by the compressor vibration model to obtain the phase angle of the harmonic injection voltage; and after determining the phase angle, increase the amplitude of the harmonic injection voltage until the amplitude is obtained when the model result meets the preset stop condition, and obtain the amplitude and phase angle of the harmonic voltage of each preset order frequency corresponding to the test point;

[0014] The amplitude and phase angle corresponding to each test point are input into the compressor vibration model to update the NVH performance of the compressor vibration model.

[0015] Optionally, before scanning different phase angles at fixed intervals to perform harmonic voltage injection and observing the NVH result output by the compressor vibration model to obtain the phase angle of the harmonic injection voltage, the method further includes:

[0016] Acquire a sample working data set of the electric compressor, wherein the sample working data set includes a plurality of groups of working parameters when the electric compressor is running;

[0017] The compressor vibration model is established based on the sample operating data set.

[0018] Optionally, the injection voltage is corrected by a correction unit in the compressor vibration model to obtain an optimal injection voltage, which is expressed by the following formula:

[0019] U=aU d +b;

[0020] Q=cQ q +d;

[0021] Wherein, U represents the optimal injection voltage obtained after the injection voltage of the d-axis is corrected, Q represents the optimal injection voltage obtained after the injection voltage of the q-axis is corrected, and U d represents the injected voltage on the d-axis, Q q represents the injected voltage of the q-axis, a represents the first speed compensation value corresponding to the current d-axis of the electric compressor, b represents the first torque compensation value corresponding to the current d-axis of the electric compressor, c represents the second speed compensation value corresponding to the current q-axis of the electric compressor, and d represents the second torque compensation value corresponding to the current q-axis of the electric compressor.

[0022] Optionally, the harmonic components of the preset order frequency include 6th harmonic, 12th harmonic and 18th harmonic; accordingly, the calculation unit calculates the injection voltage through the following formula:

[0023] U d =(U d1 +U d2 +U d3 ) / 3;

[0024] Q q =(Q q1 +Q q2 +Q q3 ) / 3;

[0025] Among them, U d represents the injected voltage on the d-axis, U d1 is the first total voltage of the d-axis, U d2 is the second total voltage of the d-axis, U d3 is the third total voltage of the d-axis; Q q is the injected voltage on the q axis, Q q1 is the first total voltage of the q axis; Q q2 is the second total voltage of the q-axis, Q q3 is the third total voltage of the q axis;

[0026] The calculation formulas for the d-axis first total voltage and the q-axis first total voltage are:

[0027] U d1 =u dn +u6sin(6ωt+θ6)+u 12 sin(6ωt+θ 12 );

[0028] Q q1 =Q qn +u6sin(6ωt+θ6)+u 12sin(6ωt+θ 12 );

[0029] The calculation formulas for the d-axis second total voltage and the q-axis second total voltage are:

[0030] U d2 =u dn +u 12 sin(6ωt+θ 12 )+u 18 sin(6ωt+θ 18 );

[0031] Q q2 =Q qn +u 12 sin(6ωt+θ 12 )+u 18 sin(6ωt+θ 18 );

[0032] The calculation formulas for the d-axis third total voltage and the q-axis third total voltage are:

[0033] U d3 =u dn +u 12 sin(6ωt+θ6)+u 18 sin(6ωt+θ 18 );

[0034] Q q3 =Q qn +u 12 sin(6ωt+θ6)+u 18 sin(6ωt+θ 18 );

[0035] Among them, u dn is the d-axis fundamental voltage, Q qn is the q-axis fundamental voltage, u6, u 12 and u 18 Respectively represent the 6th harmonic voltage amplitude, 12th harmonic voltage amplitude and 18th harmonic voltage amplitude; θ6, θ 12 and θ 18 are the initial phase angles of the 6th harmonic voltage, the 12th harmonic voltage and the 18th harmonic voltage respectively, and ω is the electrical angular velocity of the motor rotor in the electric compressor.

[0036] Optionally, before inputting the control parameters into a pre-built compressor vibration model, the method further includes:

[0037] Acquiring pressure fluctuation data when the electric compressor is running;

[0038] When the pressure fluctuation data indicates that the harmonic of the electric compressor is within the first harmonic range, triggering the step of inputting the control parameter into a pre-built compressor vibration model to obtain the optimal injection voltage;

[0039] When the pressure fluctuation data indicates that the harmonics of the electric compressor are within the second harmonic range, the compressor vibration model and the pre-built compressor model are used to correct the harmonics to obtain an optimal injection voltage;

[0040] Wherein, the second harmonic range is larger than the first harmonic range.

[0041] Optionally, the method further comprises:

[0042] A compressor model is established based on a permanent magnet synchronous motor model and a pressure ratio to simulate the overall behavior of the electric compressor;

[0043] Accordingly, when the pressure fluctuation data indicates that the harmonic of the electric compressor is within the second harmonic range, the compressor vibration model and the pre-built compressor model are used to correct the harmonic to obtain the optimal injection voltage, including:

[0044] The injection voltage is corrected using a correction unit in the compressor vibration model, and a compressor model is used to modify control parameters of the compressor model.

[0045] Optionally, the method further comprises:

[0046] Injecting harmonics according to the optimal injection voltage by a harmonic current closed-loop injection method;

[0047] In areas where closed-loop harmonic current injection is not possible, harmonics are injected according to the optimal injection voltage through an open-loop harmonic voltage injection method.

[0048] In a second aspect, a controller is provided, the controller comprising a processor and a memory; a program is stored in the memory, and the program is loaded and executed by the processor to implement the harmonic injection method described in the first aspect.

[0049] According to a third aspect, an electric compressor is provided, wherein the electric compressor comprises the above-mentioned controller.

[0050] In a fourth aspect, a computer-readable storage medium is provided, wherein a program is stored in the storage medium, and the program is loaded and executed by the processor to implement the harmonic injection method described in the first aspect.

[0051] The beneficial effects of the present application include: correcting the injection voltage through a correction unit to obtain the optimal injection voltage, being able to correct the injection voltage after the electric compressor is structurally adjusted, eliminating the need for large-scale experiments, and being able to improve the debugging efficiency of the compressor.

[0052] In addition, the combination of compressor vibration model and calibration makes harmonic injection more closely match the actual operating conditions. Harmonic open-loop injection is used in places where harmonic closed-loop injection cannot reach, thus improving the accuracy of harmonic injection.

[0053] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present application in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 is a flow chart of a harmonic injection method provided by an embodiment of the present application;

[0055] Figure 2 is a block diagram of a harmonic injection device provided by an embodiment of the present application;

[0056] Figure 3 It is a block diagram of a harmonic injection device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0057] The specific implementation methods of the present application are further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present application but are not intended to limit the scope of the present application.

[0058] Figure 1 1 is a flow chart of a harmonic injection method provided by an embodiment of the present application. This embodiment is described by taking the method used in a controller of an electric compressor as an example. The method comprises at least the following steps:

[0059] Step 101, obtaining control parameters to be input to the electric compressor.

[0060] The control parameters include the speed and torque of the electric compressor. Optionally, the control parameters are obtained by, but not limited to: obtaining the speed and torque sent by a host computer (such as the control system of the vehicle itself); or, collecting the current speed and torque of the electric compressor through a sensor.

[0061] Step 102, inputting the control parameters into a pre-built compressor vibration model, so that after receiving the control parameters to be input through the input unit in the compressor vibration model, the invalid control parameters are filtered out through the filtering unit in the compressor vibration model, and the injection voltage is calculated and output according to the control parameters and the NVH results corresponding to the control parameters through the calculation unit in the compressor vibration model; the injection voltage is corrected through the correction unit in the compressor vibration model to obtain the optimal injection voltage; the correction unit is used to correct the injection voltage when the electric compressor is replaced.

[0062] The input unit is used to input the acquired control parameters into the compressor vibration model. The filtering unit filters out invalid control parameters, including: filtering out abnormal control parameters exceeding a preset value range to obtain filtered control parameters.

[0063] In this embodiment, the calculation unit calculates and outputs the injection voltage according to the control parameters and the NVH results corresponding to the control parameters, including: obtaining the NVH data corresponding to the electric compressor under different control parameters, and screening out the target control parameters whose NVH data meet the preset requirements; determining the test points for harmonic injection based on the target control parameters; for each test point, using at least one harmonic component of a preset order frequency, scanning different phase angles at fixed intervals in the range of 0 to 2π to inject harmonic voltage, and observing the NVH results output by the compressor vibration model to obtain the phase angle of the harmonic injection voltage; and after determining the phase angle, increasing the amplitude of the harmonic injection voltage until the amplitude is obtained when the model result meets the preset stop condition, and obtaining the amplitude and phase angle of the harmonic voltage of each preset order frequency corresponding to the test point; inputting the amplitude and phase angle corresponding to each test point into the compressor vibration model to update the NVH performance of the compressor vibration model.

[0064] Schematically, the harmonic components of the preset order frequency include 6th harmonic, 12th harmonic and 18th harmonic. NVH data meeting the preset requirements means that the noise and vibration amount exceed the preset threshold value. At this time, the target control area corresponding to the NVH data that meets the preset requirements is used as the working area where harmonic voltage injection is required. At this time, the test starts from the 6P harmonic voltage, scans and finds points for injection at fixed intervals in the range of 0 to 2π, observes the change of the set order frequency or noise value online, determines the phase angle of the harmonic injection voltage, and increases the amplitude of the harmonic injection voltage until the noise or vibration amount becomes larger (that is, the preset stop condition is met); then test the 12P harmonic voltage and the 18P harmonic voltage. After scanning all the speed and torque ranges that require harmonic injection, the amplitude and phase angle information of the 6P, 12P and 18P harmonic injection voltages are input into the compressor vibration model.

[0065] In this embodiment, different phase angles are scanned at fixed intervals for harmonic voltage injection, and the NVH results output by the compressor vibration model are observed. Before obtaining the phase angle of the harmonic injection voltage, a compressor vibration model is pre-constructed. The construction process of the compressor vibration model includes: obtaining a sample working data set of the electric compressor, the sample working data set includes multiple groups of working parameters when the electric compressor is running; and establishing a compressor vibration model based on the sample working data set.

[0066] The compressor vibration model is used to simulate and predict the vibration behavior of the compressor under different operating conditions.

[0067] In this embodiment, the injection voltage is corrected by the correction unit in the compressor vibration model to obtain the optimal injection voltage, which is expressed by the following formula:

[0068] U=aU d +b;

[0069] Q=cQ q +d;

[0070] Wherein, U represents the optimal injection voltage obtained after the injection voltage of the d-axis is corrected, Q represents the optimal injection voltage obtained after the injection voltage of the q-axis is corrected, and U d represents the injected voltage on the d-axis, Q q represents the injected voltage of the q-axis, a represents the first speed compensation value corresponding to the current d-axis of the electric compressor, b represents the first torque compensation value corresponding to the current d-axis of the electric compressor, c represents the second speed compensation value corresponding to the current q-axis of the electric compressor, and d represents the second torque compensation value corresponding to the current q-axis of the electric compressor.

[0071] In this embodiment, by adding a correction unit, when used for a new compressor, the correction unit can be used to directly perform correction without repeated calculations, and a correction data set can also be added for calculation.

[0072] The calculation unit calculates the injected voltage through the following formula:

[0073] U d =(U d1 +U d2 +U d3 ) / 3;

[0074] Q q =(Q q1 +Q q2 +Q q3 ) / 3;

[0075] Among them, U d represents the injected voltage on the d-axis, U d1 is the first total voltage of the d-axis, Ud2 is the second total voltage of the d-axis, U d3 is the third total voltage of the d-axis; Q q is the injected voltage on the q axis, Q q1 is the first total voltage of the q axis; Q q2 is the second total voltage of the q-axis, Q q3 is the third total voltage of the q axis;

[0076] The calculation formulas for the d-axis first total voltage and the q-axis first total voltage are:

[0077] U d1 =u dn +u6sin(6ωt+θ6)+u 12 sin(6ωt+θ 12 );

[0078] Q q1 =Q qn +u6sin(6ωt+θ6)+u 12 sin(6ωt+θ 12 );

[0079] The calculation formulas for the d-axis second total voltage and the q-axis second total voltage are:

[0080] U d2 =u dn +u 12 sin(6ωt+θ 12 )+u 18 sin(6ωt+θ 18 );

[0081] Q q2 =Q qn +u 12 sin(6ωt+θ 12 )+u 18 sin(6ωt+θ 18 );

[0082] The calculation formulas for the d-axis third total voltage and the q-axis third total voltage are:

[0083] U d3 =u dn +u 12 sin(6ωt+θ6)+u 18 sin(6ωt+θ 18 );

[0084] Q q3 =Q qn +u 12 sin(6ωt+θ6)+u 18 sin(6ωt+θ 18 );

[0085] Among them, u dn is the d-axis fundamental voltage, Q qn is the q-axis fundamental voltage, u6, u 12 and u 18 Respectively represent the 6th harmonic voltage amplitude, 12th harmonic voltage amplitude and 18th harmonic voltage amplitude; θ6, θ 12 and θ 18 They are the initial phase angles of the 6th harmonic voltage, the initial phase angles of the 12th harmonic voltage and the initial phase angles of the 18th harmonic voltage, and ω is the electrical angular velocity of the motor rotor in the electric compressor.

[0086] Optionally, the controller can also obtain pressure fluctuation data during the operation of the electric compressor before inputting the control parameters into a pre-built compressor vibration model; when the pressure fluctuation data indicates that the harmonics of the electric compressor are within the first harmonic range, trigger the step of inputting the control parameters into the pre-built compressor vibration model to obtain the optimal injection voltage; when the pressure fluctuation data indicates that the harmonics of the electric compressor are within the second harmonic range, use the compressor vibration model and the pre-built compressor model to correct the harmonics to obtain the optimal injection voltage; wherein the second harmonic range is larger than the first harmonic range.

[0087] Among them, the compressor model is a comprehensive model that combines the permanent magnet synchronous motor model and the pressure ratio to simulate the overall behavior of the compressor. This model can be used to predict the suction pressure, exhaust pressure, power consumption and vibration characteristics of the compressor under different load conditions. The model usually includes the thermodynamic process, fluid dynamics and mechanical dynamics of the compressor. The input of the electric compressor is voltage and current, and the output is speed, power, suction pressure, exhaust pressure and vibration harmonics.

[0088] The construction process of the compressor model includes: establishing a compressor model based on a permanent magnet synchronous motor model and a pressure ratio. Accordingly, when the pressure fluctuation data indicates that the harmonics of the electric compressor are within the second harmonic range, the compressor vibration model and the pre-constructed compressor model are used to correct the harmonics to obtain the optimal injection voltage, including: using the correction unit in the compressor vibration model to correct the injection voltage, and using the compressor model to modify the control parameters of the compressor model. The control parameters of the compressor model include motor parameters and pressure control closed-loop control coefficients, etc. This embodiment does not limit the type of control parameters of the compressor model.

[0089] Optionally, after obtaining the optimal injection voltage, the controller can inject harmonics according to the optimal injection voltage through the harmonic current closed-loop injection method; in areas where harmonic current closed-loop injection cannot be performed, harmonics can be injected according to the optimal injection voltage through the harmonic voltage open-loop injection method.

[0090] Optionally, the controller can also calculate the harmonic current loss energy and the compressor operating efficiency according to the output harmonic current. When the efficiency is low, the compressor operating load is reduced to perform power protection and avoid abnormal shutdown of the compressor.

[0091] Optionally, the controller may also obtain experimental data of the motor compression model to further optimize the compressor vibration model and the compressor model.

[0092] To sum up, the harmonic injection method provided in this embodiment corrects the injection voltage through the correction unit to obtain the optimal injection voltage. The injection voltage can be corrected after the electric compressor is structurally adjusted, without the need for large-scale experiments, thereby improving the debugging efficiency of the compressor.

[0093] In addition, the combination of compressor vibration model and calibration makes harmonic injection more closely match the actual operating conditions. Harmonic open-loop injection is used in places where harmonic closed-loop injection cannot reach, thus improving the accuracy of harmonic injection.

[0094] Figure 2 2 is a block diagram of a harmonic injection device provided by an embodiment of the present application. The device comprises at least the following modules: a parameter acquisition module 210 and a voltage determination module 220 .

[0095] A parameter acquisition module 210, for acquiring control parameters to be input into the electric compressor;

[0096] The voltage determination module 220 is used to input the control parameters into a pre-constructed compressor vibration model, so that after receiving the control parameters to be input through the input unit in the compressor vibration model, invalid control parameters are filtered out through the filtering unit in the compressor vibration model, and the calculation unit in the compressor vibration model calculates and outputs the injection voltage according to the control parameters and the NVH results corresponding to the control parameters; the injection voltage is corrected by the correction unit in the compressor vibration model to obtain the optimal injection voltage; the correction unit is used to correct the injection voltage when the electric compressor is replaced.

[0097] For relevant details, refer to the above method embodiment.

[0098] It should be noted that: the harmonic injection device provided in the above embodiment only uses the division of the above functional modules as an example when performing harmonic injection. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the harmonic injection device is divided into different functional modules to complete all or part of the functions described above. In addition, the harmonic injection device provided in the above embodiment belongs to the same concept as the harmonic injection method embodiment. The specific implementation process is detailed in the method embodiment and will not be repeated here.

[0099] Figure 3 30 is a block diagram of a controller provided by an embodiment of the present application. The device at least includes a processor 301 and a memory 302.

[0100] The processor 301 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 301 may be implemented in at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), and PLA (Programmable Logic Array). The processor 301 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a CPU (Central Processing Unit); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 301 may be integrated with a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 301 may also include an AI (Artificial Intelligence) processor, which is used to process computing operations related to machine learning.

[0101] The memory 302 may include one or more computer-readable storage media, which may be non-transitory. The memory 302 may also include a high-speed random access memory and a non-volatile memory, such as one or more disk storage devices and flash memory storage devices. In some embodiments, the non-transitory computer-readable storage medium in the memory 302 is used to store at least one instruction, which is used to be executed by the processor 301 to implement the harmonic injection method provided in the method embodiment of the present application.

[0102] In some embodiments, the harmonic injection device may further optionally include: a peripheral device interface and at least one peripheral device. The processor 301, the memory 302 and the peripheral device interface may be connected via a bus or a signal line. Each peripheral device may be connected to the peripheral device interface via a bus, a signal line or a circuit board. Schematically, the peripheral devices include but are not limited to: a radio frequency circuit, a touch display screen, an audio circuit, and a power supply.

[0103] Of course, the harmonic injection device may also include fewer or more components, which is not limited in this embodiment.

[0104] Optionally, the present application also provides a computer-readable storage medium, in which a program is stored, and the program is loaded and executed by a processor to implement the harmonic injection method of the above method embodiment.

[0105] Optionally, the present application also provides a computer product, which includes a computer-readable storage medium, wherein the computer-readable storage medium stores a program, and the program is loaded and executed by a processor to implement the harmonic injection method of the above method embodiment.

[0106] Optionally, the present application also provides an electric compressor, which includes a computer-readable storage medium, in which a program is stored, and the program is loaded and executed by a processor to implement the harmonic injection method of the above method embodiment.

[0107] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0108] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A harmonic injection method, characterized in that: The method comprises: acquiring control parameters to be input into the electric compressor; The control parameters are input into a pre-constructed compressor vibration model, so that after the input unit in the compressor vibration model receives the control parameters to be input, the filtering unit in the compressor vibration model filters out invalid control parameters, and the calculation unit in the compressor vibration model calculates and outputs an injection voltage according to the control parameters and the NVH results corresponding to the control parameters; the correction unit in the compressor vibration model corrects the injection voltage to obtain an optimal injection voltage; the correction unit is used to correct the injection voltage when the electric compressor is replaced.

2. The method according to claim 1, characterized in that The calculation unit calculates and outputs the injection voltage according to the control parameter and the NVH result corresponding to the control parameter, including: Obtaining NVH data corresponding to the electric compressor under different control parameters, and screening out target control parameters whose NVH data meet preset requirements; Determining a test point for harmonic injection based on the target control parameter; For each test point, use at least one harmonic component of a preset order frequency, scan different phase angles at fixed intervals within the range of 0 to 2π to perform harmonic voltage injection, and observe the NVH results output by the compressor vibration model to obtain the phase angle of the harmonic injection voltage; and after determining the phase angle, increase the amplitude of the harmonic injection voltage until the amplitude is obtained when the model result meets the preset stop condition, and obtain the amplitude and phase angle of the harmonic voltage of each preset order frequency corresponding to the test point; The amplitude and phase angle corresponding to each test point are input into the compressor vibration model to update the NVH performance of the compressor vibration model.

3. The method according to claim 2, characterized in that Before the step of scanning different phase angles at fixed intervals to perform harmonic voltage injection and observing the NVH results output by the compressor vibration model to obtain the phase angle of the harmonic injection voltage, the method further includes: Acquire a sample working data set of the electric compressor, wherein the sample working data set includes a plurality of groups of working parameters when the electric compressor is running; The compressor vibration model is established based on the sample operating data set.

4. The method according to claim 2, characterized in that: The injection voltage is corrected by the correction unit in the compressor vibration model to obtain the optimal injection voltage, which is expressed by the following formula: U=aU d +b; Q=cQ q +d; Wherein, U represents the optimal injection voltage obtained after the injection voltage of the d-axis is corrected, Q represents the optimal injection voltage obtained after the injection voltage of the q-axis is corrected, and U d represents the injected voltage on the d-axis, Q q represents the injected voltage of the q-axis, a represents the first speed compensation value corresponding to the current d-axis of the electric compressor, b represents the first torque compensation value corresponding to the current d-axis of the electric compressor, c represents the second speed compensation value corresponding to the current q-axis of the electric compressor, and d represents the second torque compensation value corresponding to the current q-axis of the electric compressor.

5. The method according to claim 4, characterized in that The harmonic components of the preset order frequency include 6th harmonic, 12th harmonic and 18th harmonic; accordingly, the calculation unit calculates the injection voltage through the following formula: IN d =(U d1 +U d2 +U d3 ) / 3; Q q =(Q q1 +Q q2 +Q q3 ) / 3; Among them, U d represents the injected voltage on the d-axis, U d1 is the first total voltage of the d-axis, U d2 is the second total voltage of the d-axis, U d3 is the third total voltage of the d-axis; Q q is the injected voltage on the q axis, Q q1 is the first total voltage of the q axis; Q q2 is the second total voltage of the q-axis, Q q3 is the third total voltage of the q axis; The calculation formulas for the d-axis first total voltage and the q-axis first total voltage are: U d1 =u dn +u6sin(6ωt+θ6)+u 12 sin(6ωt+θ 12 ); Q q1 =Q qn +u6sin(6ωt+θ6)+u 12 sin(6ωt+θ 12 ); The calculation formulas for the d-axis second total voltage and the q-axis second total voltage are: U d2 =u dn +u 12 sin(6ωt+θ 12 )+u 18 sin(6ωt+θ 18 ); Q q2 =Q qn +u 12 sin(6ωt+θ 12 )+u 18 sin(6ωt+θ 18 ); The calculation formulas for the d-axis third total voltage and the q-axis third total voltage are: U d3 =u dn +u 12 sin(6ωt+θ6)+u 18 sin(6ωt+θ 18 ); Q q3 =Q qn +u 12 sin(6ωt+θ6)+u 18 sin(6ωt+θ 18 ); Among them, u dn is the d-axis fundamental voltage, Q qn is the q-axis fundamental voltage, u6, u 12 and u 18 Respectively represent the 6th harmonic voltage amplitude, 12th harmonic voltage amplitude and 18th harmonic voltage amplitude; θ6, θ 12 and θ 18 are the initial phase angles of the 6th harmonic voltage, the 12th harmonic voltage and the 18th harmonic voltage respectively, and ω is the electrical angular velocity of the motor rotor in the electric compressor.

6. The method according to claim 1, characterized in that Before inputting the control parameters into the pre-built compressor vibration model, the method further includes: Acquiring pressure fluctuation data when the electric compressor is running; When the pressure fluctuation data indicates that the harmonic of the electric compressor is within the first harmonic range, triggering the step of inputting the control parameter into a pre-built compressor vibration model to obtain the optimal injection voltage; When the pressure fluctuation data indicates that the harmonics of the electric compressor are within the second harmonic range, the compressor vibration model and the pre-built compressor model are used to correct the harmonics to obtain an optimal injection voltage; Wherein, the second harmonic range is larger than the first harmonic range.

7. The method according to claim 6, characterized in that The method further comprises: A compressor model is established based on a permanent magnet synchronous motor model and a pressure ratio to simulate the overall behavior of the electric compressor; Accordingly, when the pressure fluctuation data indicates that the harmonic of the electric compressor is within the second harmonic range, the compressor vibration model and the pre-built compressor model are used to correct the harmonic to obtain the optimal injection voltage, including: The injection voltage is corrected using a correction unit in the compressor vibration model, and a compressor model is used to modify control parameters of the compressor model.

8. The method according to claim 1, characterized in that The method further comprises: Injecting harmonics according to the optimal injection voltage by a harmonic current closed-loop injection method; In areas where closed-loop harmonic current injection is not possible, harmonics are injected according to the optimal injection voltage through an open-loop harmonic voltage injection method.

9. A controller, characterized in that: The controller comprises a processor and a memory; the memory stores a program, and the program is loaded and executed by the processor to implement the harmonic injection method according to any one of claims 1 to 8.

10. An electric compressor, characterized in that: The electric compressor includes the controller according to claim 9.

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