Harmonic current suppression method for electric machine and vehicle

Abstract

The application relates to a harmonic current suppression method of a motor and a vehicle, and relates to the technical field of vehicle motors. The method comprises the following steps: filtering motor currents in a two-phase static coordinate system to obtain motor filtered currents; wherein the filtering is used for extracting 6K pulse rectification harmonics; determining a 6K rotor electric angle estimation value of the motor based on the motor filtered currents and a 6K rotor electric speed observation value of the motor; wherein the 6K rotor electric speed observation value is determined based on a motor rotor mechanical speed observation value of the motor; determining a 6K harmonic current estimation value of the motor based on the 6K rotor electric angle estimation value and the motor currents in a two-phase rotating coordinate system; and suppressing the harmonic currents of the motor based on the 6K harmonic current estimation value, which can effectively suppress the harmonic currents and further suppress motor noises caused by the harmonic currents.

Description

Technical Field

[0001] This invention relates to the field of vehicle motor technology, specifically to a method for suppressing harmonic current in a motor and a vehicle. Background Technology

[0002] Permanent magnet synchronous motors (PMSMs) are widely used in the drive systems of new energy vehicles due to their significant advantages such as high power density, high efficiency, and fast dynamic response. However, in actual operation, due to the combined effects of motor-related factors such as cogging effect, winding distribution, and magnetic circuit saturation, as well as inverter factors such as dead zone effect and tube voltage drop, specific order harmonics are introduced into the motor current. This leads to problems such as uneven vehicle power output, increased losses, and noise and vibration, seriously affecting the driving experience.

[0003] Currently, existing harmonic suppression methods extract specific frequency harmonics by establishing a multi-phase rotating coordinate system and then using a proportional-integral controller to calculate compensation voltage for cancellation. While this method can theoretically suppress harmonics, its algorithm logic is extremely complex and places very high demands on the chip hardware resources of the motor controller, limiting its application in practical control. Secondly, vehicles need to adjust the power output of the drive system in real time according to the driver's needs, resulting in continuously changing motor operating conditions. Traditional harmonic suppression methods are mostly designed for fixed load conditions and are difficult to adapt to such dynamically changing operating conditions.

[0004] Therefore, how to effectively suppress specific order current harmonics under varying operating conditions of new energy vehicles is a technical challenge that urgently needs to be solved in the field of new energy vehicle drive systems. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this application is to provide a method for suppressing harmonic current in an electric motor and a vehicle that can effectively suppress harmonic current in the electric motor.

[0006] In a first aspect, embodiments of this application provide a method for suppressing harmonic current in a motor. The method includes: filtering the motor current in a two-phase stationary coordinate system to obtain a filtered motor current; wherein the filtering is used to extract 6K-pulse rectified harmonics; determining an estimated 6K-order rotor electrical angle based on the filtered motor current and the observed 6K-order rotor electrical angular velocity of the motor; wherein the observed 6K-order rotor electrical angular velocity is determined based on the observed rotor mechanical angular velocity of the motor; determining an estimated 6K-order harmonic current based on the estimated 6K-order rotor electrical angle and the motor current in a two-phase rotating coordinate system; and suppressing the harmonic current in the motor based on the estimated 6K-order harmonic current.

[0007] Based on the above technical solution, this application first filters the specific frequency band of the 6K pulse rectification in a two-phase stationary coordinate system, enabling high-fidelity extraction of harmonic characteristics without interfering with fundamental frequency control. Subsequently, the 6Kth electrical angular velocity is calculated using the existing rotor mechanical angular velocity of the motor, ensuring real-time synchronization between frequency tracking and speed changes. Based on this, the 6Kth rotor electrical angle is reconstructed using the filtered current, and the periodic AC harmonics are converted into easily processed DC components in the corresponding 6K rotating coordinate system, achieving decoupling and separation of harmonics from the fundamental frequency. Finally, harmonic suppression is implemented based on accurate estimates of the 6Kth harmonic current, effectively suppressing specific-order current harmonics under varying operating conditions, thereby reducing motor noise caused by harmonic currents.

[0008] In one possible approach, the estimated value of the 6Kth rotor electrical angle of the motor is determined based on the motor filter current and the observed values ​​of the 6Kth rotor electrical angular velocity. This includes: determining the rotor phase deviation signal of the motor based on the motor filter current; determining the baseline estimated value of the 6Kth rotor electrical angular velocity based on the rotor phase deviation signal; determining the estimation deviation feedback compensation value based on the estimation deviation between the observed value of the 6Kth rotor electrical angular velocity and the previous estimated value of the 6Kth rotor electrical angular velocity; determining the current estimated value of the 6Kth rotor electrical angular velocity based on the baseline estimated value and the estimation deviation feedback compensation value; and determining the estimated value of the 6Kth rotor electrical angle based on the current estimated value.

[0009] Based on the above technical solution, this application constructs a phase closed-loop adjustment mechanism for a phase-locked loop (PLL) by extracting the rotor phase deviation signal using the filtered 6K harmonic current in a two-phase stationary coordinate system. This effectively ensures precise synchronization between the harmonic rotating coordinate system and the actual 6K harmonic vector. Simultaneously, by introducing the observed 6K rotor electrical angular velocity derived from the motor's mechanical speed as a feedforward reference, the capture range of the phase loop is significantly reduced, enabling the system to quickly relock under variable speed and acceleration / deceleration conditions, avoiding the problem of easy lockout in traditional pure PLLs. Furthermore, the feedback compensation mechanism corrects the deviation between the observed and estimated electrical angular velocity values ​​in real time, suppressing model errors caused by filter phase shift, parameter changes, and integral drift, further improving the steady-state accuracy and robustness of the estimation.

[0010] In one possible approach, the estimation deviation feedback compensation value is determined based on the estimation deviation between the 6Kth rotor electrical angular velocity observation value and the previous estimated value of the 6Kth rotor electrical angular velocity, including: determining the estimation deviation feedback compensation value based on the estimation deviation, the rotor phase deviation signal, and the feedback compensation coefficient.

[0011] Based on the above technical solution, this application determines the estimation deviation feedback compensation value by combining the estimation deviation, rotor phase deviation signal and feedback compensation coefficient, so as to ensure that a smooth and error-free 6K electric angular velocity estimation value can be output in the entire speed range.

[0012] In one possible approach, determining the baseline estimate of the 6Kth rotor electrical angular velocity of the motor based on the rotor phase deviation signal includes: inputting the rotor phase deviation signal into a proportional-integral controller in a phase-locked loop to obtain the baseline estimate output by the proportional-integral controller.

[0013] Based on the above technical solution, the proportional element of the proportional-integral controller in this application can respond instantly to rotor phase deviation, providing rapid phase traction during motor startup or sudden speed changes, significantly shortening the observer's lock-in time. The integral element, on the other hand, focuses on eliminating steady-state errors, automatically compensating for constant phase shifts caused by filter phase shifts, inverter dead zones, or changes in motor parameters, ensuring strict alignment between the 6Kth order rotating coordinate system and the true harmonic magnetic field. This structure converts AC current phase deviation into DC electrical angular velocity correction, and the bandwidth and stability of the observer can be flexibly configured by adjusting the proportional-integral parameters, ensuring robustness in filtering high-frequency noise during high-speed operation.

[0014] In one possible approach, determining the rotor phase deviation signal of the motor based on the motor filter current includes: inputting the motor filter current into a phase error detector in a phase-locked loop to obtain the rotor phase deviation signal.

[0015] In one possible approach, the estimated value of the 6Kth harmonic current of the motor is determined based on the estimated value of the 6Kth rotor electrical angle and the motor current in a two-phase rotating coordinate system. This includes: substituting the estimated value of the 6Kth rotor electrical angle into a first objective mathematical model to obtain a second objective mathematical model; using the first objective mathematical model to estimate the 6Kth harmonic current in the motor current in a two-phase rotating coordinate system; performing parameter learning on the second objective mathematical model with the objective of minimizing the deviation between the actual value and the estimated value of the 6Kth harmonic current to obtain a third objective mathematical model; and determining the 6Kth harmonic current estimated by the third objective mathematical model as the estimated value of the 6Kth harmonic current.

[0016] Based on the above technical solution, this application utilizes the accurately estimated 6Kth rotor electrical angle as a transformation reference, encapsulates the dynamic characteristics of the 6Kth harmonic current in a two-phase rotating coordinate system into a first objective mathematical model, and uses the actually observed harmonic current as a monitoring signal to iteratively update the model parameters online by minimizing the estimation deviation (i.e., obtaining the third objective mathematical model). This method no longer relies solely on fixed motor electrical parameters, but rather uses a self-correcting approach to approximate the dynamics of the real physical system, thereby adaptively compensating for the effects of digital control delay, inverter nonlinearity, and unmodeled dynamics.

[0017] In one possible approach, a first objective mathematical model is used to represent the current estimate on the objective axis, which is equal to the sum of the actual fundamental current value on the objective axis and the estimated 6K harmonic current value on the objective axis; the objective axis is the direct axis and the quadrature axis; the actual fundamental current value on the objective axis is extracted from the motor current in a two-phase rotating coordinate system; with the objective of minimizing the deviation between the actual value and the estimated value of the 6K harmonic current, the second objective mathematical model is subjected to parameter learning to obtain a third objective mathematical model, which includes: with the objective of minimizing the deviation between the motor current in the two-phase rotating coordinate system and the current output by the second objective mathematical model, the second objective mathematical model is subjected to parameter learning to obtain a third objective mathematical model.

[0018] Based on the above technical solution, this application uses minimizing the deviation between the true value and the estimated value of the 6Kth harmonic current as the learning objective. Compared with constructing harmonic errors separately, it can more comprehensively reflect the degree of fit of the model to the actual physical system, forcing the learning algorithm to automatically compensate for the model distortion caused by digital control delay, inverter nonlinearity and coordinate transformation truncation error while correcting the characteristics of the 6Kth harmonic.

[0019] In one possible approach, the estimated 6K harmonic current on the direct axis is the sum of the first and second products; the estimated 6K harmonic current on the quadrature axis is the sum of the third and fourth products; the first product is the product of the first direct axis coefficient and the cosine term of the estimated 6K rotor electrical angle; the second product is the product of the second direct axis coefficient and the sine term of the estimated 6K rotor electrical angle; the third product is the product of the first quadrature axis coefficient and the cosine term of the estimated 6K rotor electrical angle; and the fourth product is the product of the second quadrature axis coefficient and the negative value corresponding to the sine term of the estimated 6K rotor electrical angle.

[0020] One possible approach involves suppressing the incoming harmonic current of the motor based on the estimated 6K harmonic current, including: determining the compensation voltage corresponding to the 6th harmonic current on the target shaft based on the estimated 6th harmonic current on the target shaft; and suppressing the incoming harmonic current of the motor based on the compensation voltage.

[0021] Based on the above technical solution, this application calculates the corresponding compensation voltage based on the 6th harmonic current detected by the target shaft, and then uses the compensation voltage to cancel the 6th harmonic current in the motor, which can quickly and effectively achieve harmonic suppression.

[0022] In one possible approach, the compensation voltage corresponding to the sixth harmonic current on the target axis is determined based on the estimated value of the sixth harmonic current on the target axis, including: inputting the estimated value of the sixth harmonic current on the target axis into a compensation network to obtain the compensation voltage corresponding to the sixth harmonic current on the target axis; wherein, the compensation network is used to represent the correspondence between the harmonic current and the compensation voltage when the harmonic current is suppressed.

[0023] Based on the above technical solution, this application feeds the estimated value of the 6th harmonic current of the target axis into the compensation network. The network has a built-in correspondence between harmonic current and compensation voltage, and quickly calculates the compensation voltage corresponding to the 6th harmonic current on the target axis.

[0024] In one possible approach, the motor current in a two-phase stationary coordinate system is filtered to obtain the motor filtered current. This includes: inputting the motor current in the two-phase stationary coordinate system into a complex filter to obtain the motor filtered current after filtering by the complex filter; wherein, the center frequency of the complex filter is the frequency corresponding to the 6K pulse rectified harmonic, and the cutoff frequency is positively correlated with the observed value of the motor rotor electric angular velocity; the cutoff frequency is used to define the bandpass frequency range.

[0025] Based on the above technical solution, this application employs a complex filter with a center frequency aligned to the 6Kth rectified harmonic to extract the current signal. Simultaneously, the filter's passband range increases and decreases synchronously with the motor's electric speed. On one hand, this accurately selects the target harmonic and filters out irrelevant interference signals, resulting in high harmonic extraction purity. On the other hand, the filter bandwidth automatically adapts to changes in speed, ensuring stable and complete detection of the 6Kth harmonic regardless of whether the motor is operating at high or low speed. This avoids harmonic signal loss or noise contamination, providing a reliable raw signal for subsequent harmonic suppression.

[0026] Secondly, embodiments of this application provide a harmonic current suppression device for an electric motor, the device comprising: a filtering unit, a first determining unit, a second determining unit, and a control unit.

[0027] The filtering unit is used to filter the motor current in the two-phase stationary coordinate system to obtain the motor filtered current; the filtering is used to extract the 6K pulse rectified harmonics.

[0028] The first determining unit is used to determine the estimated value of the 6Kth rotor electrical angle of the motor based on the motor filter current and the observed value of the 6Kth rotor electrical angular velocity of the motor; wherein the observed value of the 6Kth rotor electrical angular velocity is determined based on the observed value of the motor rotor mechanical angular velocity.

[0029] The second determining unit is used to determine the estimated value of the 6Kth harmonic current of the motor based on the estimated value of the 6Kth rotor electrical angle and the motor current in the two-phase rotating coordinate system.

[0030] The control unit is used to suppress the incoming harmonic current of the motor based on the estimated value of the 6Kth harmonic current.

[0031] Thirdly, embodiments of this application provide a vehicle that uses the harmonic current suppression method for the motor described in the first aspect and any possible implementation thereof to suppress harmonic current.

[0032] Fourthly, embodiments of this application provide an electronic device, including: a processor; and a memory for storing processor-executable instructions. The processor is configured to execute instructions to implement the harmonic current suppression method for a motor described in the first aspect and any possible implementation thereof.

[0033] Fifthly, this application provides a computer-readable storage medium that, when the instructions in the computer-readable storage medium are executed by a processor of an electronic device, enables the electronic device to perform the harmonic current suppression method for a motor described in the first aspect and any possible implementation thereof.

[0034] Sixthly, embodiments of this application provide a computer program product, which includes computer instructions that, when executed on an electronic device, cause the electronic device to perform the harmonic current suppression method for a motor described in the first aspect and any possible implementation thereof.

[0035] It should be noted that the technical effects of any of the implementation methods in aspects two through six can be found in the technical effects of the corresponding implementation methods in aspect one, and will not be repeated here.

[0036] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this application or the background art, the accompanying drawings used in the embodiments of this application will be described below.

[0038] Figure 1 This is a schematic diagram of the structure of a harmonic current suppression system for an electric motor provided in an embodiment of this application; Figure 2 A schematic flowchart illustrating a method for suppressing harmonic currents in a motor, provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of a d-axis voltage compensation network provided in an embodiment of this application; Figure 4 A schematic diagram of the structure of a q-axis voltage compensation network provided in an embodiment of this application; Figure 5 A schematic diagram illustrating a strategy for suppressing harmonic currents in a motor, provided in an embodiment of this application; Figure 6 This is a schematic diagram of a phase-locked loop provided in an embodiment of this application; Figure 7 This is a schematic diagram of the structure of a d-axis current decomposer provided in an embodiment of this application; Figure 8This is a schematic diagram of the structure of a q-axis current resolver provided in an embodiment of this application; Figure 9 A schematic diagram of the structure of a harmonic current suppression device for an electric motor provided in an embodiment of this application; Figure 10 This is a block diagram of an electronic device provided in an embodiment of this application. Detailed Implementation

[0039] To enable those skilled in the art to better understand the technical solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0040] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0041] In the embodiments of this application, the words "exemplarily," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplarily," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the words "exemplarily," "for example," or "for instance" is intended to present the relevant concepts in a specific manner.

[0042] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0043] The harmonic current suppression of the motor provided in this application embodiment can be applied to vehicles. Vehicles can also be referred to as vehicles, mobile carriers, electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), fuel cell vehicles (FCVs), autonomous vehicles, intelligent and connected vehicles (ICVs), driverless vehicles, etc.

[0044] In this application, the vehicle can be a sedan, a sport utility vehicle (SUV), a truck, an electric vehicle, a motorcycle, a tricycle, a special vehicle (such as an ambulance, fire truck, police car, etc.), a driverless taxi, an intelligent connected bus, an autonomous logistics vehicle, an electric truck, etc. Furthermore, this method is also applicable to various special-purpose vehicles, such as agricultural vehicles, mining vehicles, forestry vehicles, airport vehicles, and port vehicles. This application does not impose specific limitations in this regard.

[0045] like Figure 1 As shown in the figure, a harmonic current suppression system for a motor provided in this application includes: a controller 101, a motor 102, and a signal acquisition device 103 deployed in a vehicle 100. The controller 101 is communicatively connected to the motor 102 and the signal acquisition device 103.

[0046] In this embodiment, the controller 101 may include, but is not limited to, a vehicle control unit (VCU), a motor control unit (MCU), etc.

[0047] In this embodiment of the application, the motor 102 may include an inner-mounted permanent magnet synchronous motor (IPMSM), a surface-mounted permanent magnet synchronous motor (SPMSM), etc., and there is no limitation thereto.

[0048] In this embodiment, the signal acquisition device 103 may include a current sensor. The current sensor is used to acquire the three-phase current signal of the motor 102. In this embodiment, the current sensor may include a Hall effect current sensor and a shunt resistor, etc., and is not limited thereto.

[0049] In some embodiments, the signal acquisition device 103 can acquire the three-phase current signal of the motor 102 in real time and send the three-phase current signal to the controller 101. Accordingly, the controller 101 can perform coordinate transformation on the three-phase current signal to obtain the motor current (i.e., α-axis current) in a two-phase stationary coordinate system (i.e., αβ coordinate system). β-axis current Then, controller 101 can use a complex filter to filter the motor current in the two-phase stationary coordinate system to obtain the filtered motor current. Based on the filtered motor current and the observed 6Kth rotor electrical angular velocity of motor 102, controller 101 can determine the estimated 6Kth rotor electrical angle of motor 102. Next, controller 101 can determine the estimated 6Kth harmonic current of motor 102 based on the estimated 6Kth rotor electrical angle and the motor current in the two-phase rotating coordinate system. Finally, based on the estimated 6Kth harmonic current, controller 101 can determine the compensation voltages corresponding to the 6th harmonic currents on the d-axis (also called the direct axis) and q-axis (also called the quadrature axis) in the dq coordinate system, i.e., the d-axis compensation voltage and the q-axis compensation voltage. Based on the d-axis compensation voltage and the q-axis compensation voltage, controller 102 is controlled to operate, thereby suppressing the harmonic currents of motor 102.

[0050] For ease of understanding, the harmonic current suppression method for motors provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0051] like Figure 2 As shown in the embodiment of this application, a method for suppressing harmonic currents in a motor includes: S201. Filter the motor current in the two-phase stationary coordinate system to obtain the motor filtered current.

[0052] The three-phase current of a motor includes fundamental current and harmonic current. The fundamental current is the sinusoidal component of the three-phase current with a frequency equal to the fundamental frequency of the power supply. It generates a rotating fundamental magnetic field, which is the fundamental power source that interacts with the rotor magnetic field, producing constant electromagnetic torque and driving the motor's continuous rotation. Harmonic currents are sinusoidal components superimposed on the fundamental current, with frequencies that are integer multiples of the fundamental frequency. The harmonic magnetic fields generated by the harmonic currents interact with the fundamental magnetic field or other harmonic magnetic fields, producing a series of higher-frequency oscillating electromagnetic forces, thereby exciting vibrations and noise over a wider frequency band.

[0053] Based on the above, in this embodiment, by filtering the motor current in a two-phase stationary coordinate system, 6K-pulse rectified harmonics can be extracted for harmonic suppression control. Here, K = 1, 2, ..., N, where N is a positive integer.

[0054] In some embodiments, the controller incorporates a complex filter. Based on this, the signal acquisition device can acquire the three-phase current of the motor in real time and send it to the controller. Correspondingly, the controller can perform coordinate transformation on the three-phase current to obtain the motor current (i.e., the α-axis current) in a two-phase stationary coordinate system (hereinafter referred to as the αβ coordinate system). β-axis current After that, the controller can control the α-axis current. and β-axis current Input a complex filter to obtain the filtered motor current (i.e., current) after the complex filter is applied. and current ).

[0055] The center frequency of the complex filter is the frequency corresponding to the 6K pulse rectified harmonic; the cutoff frequency is used to define the bandpass frequency range. The cutoff frequency is positively correlated with the observed value of the motor rotor electric angular velocity (i.e., electric angular velocity). That is, the larger the observed value of the motor rotor electric angular velocity, the larger the cutoff frequency, and the smaller the observed value of the motor rotor electric angular velocity, the smaller the cutoff frequency.

[0056] In this embodiment of the application, the setting principle and working principle of the complex filter are as follows: Generally, the transfer function of a traditional first-order low-pass filter is given below. It can be represented as: (Formula 1) in, The cutoff frequency of the filter determines its bandwidth and response speed. This represents a complex frequency variable (also known as the Laplace operator). This represents the transfer function of a first-order low-pass filter.

[0057] According to the frequency shift property of the Laplace transform (also known as the complex frequency shift property), if the time-domain signal... The Laplace transform is Then the time-domain signal The Laplace transform is That is, introducing complex exponents in the time domain. This is equivalent to shifting the spectrum of the original signal in the complex frequency domain (s-domain), with a shift amount of... .

[0058] In motor control applications, it is often necessary to correlate the filter characteristics in a two-phase stationary coordinate system (αβ coordinate system) with those in a two-phase rotating coordinate system (dq coordinate system). Mapping the characteristics of a traditional first-order low-pass filter to a coordinate system with angular frequency... For a rotating stationary coordinate system, the frequency shift property of the Laplace transform is used to let... (Because the angular frequency of the two-phase rotating coordinate system is) The corresponding shift in the complex frequency domain is time domain signal Multiply Its Laplace transform is ),Right now .

[0059] Based on the above, use Substituting into the formula, we can obtain the transfer function of the complex filter. : (Formula 2) The above derivation applies to the current in the αβ coordinate system. Current The filtered current is obtained by performing filtering. and current Among them, current Current The corresponding complex expression satisfies the following formula 3, the filtered current. and current The complex expression of satisfies the following formula 4.

[0060] (Formula 3) (Formula 4) Substituting Equations 3 and 4 into the complex filter transfer function respectively... ,get: (Formula 5) Formula 5 above is expressed in complex form. By further expanding the real and imaginary parts of the complex numbers in Formula 5, we can obtain the following equations (i.e., Formulas 6 and 7): (Formula 6) (Formula 7) Due to the requirements of actual model building, Equations 6 and 7 above can be discretized according to the forward Euler formula to obtain the filtered current. The expression for (Equation 8 below), and the filtered current. The expression is (Formula 9 below).

[0061] (Formula 8) (Formula 9) in, Indicates the current time; Indicates the next moment; This indicates the electrical angular velocity of the motor rotor; This indicates the inverter's interruption cycle (sampling and control cycle). Indicates the cutoff frequency of the filter; Indicates the current at the next moment Filter current; Indicates the current at the next moment The filtered current.

[0062] Analysis of the complex filter transfer function reveals the filter's cutoff frequency. The cutoff frequency determines the degree of attenuation of signals at different frequencies by the filter. The smaller the value, the lower the electric angular velocity. The greater the suppression of frequencies other than the electrical angular frequency (or angular frequency), the stronger the suppression effect. To achieve accurate extraction of a frequency-stable signal even when the signal frequency changes, one can... The design dynamically varies with the rotational speed to achieve the cutoff frequency. Tracking rotational speed (electric angular velocity) The change in frequency ( ) ensures accurate extraction of the target frequency (such as stable frequency components) while suppressing interference from non-target frequencies, even as the signal frequency fluctuates. Based on this, the cutoff frequency... The following formula 10 is satisfied: (Formula 10) in, These represent the filter calibration coefficients, which are calibration parameters that balance the filter's response time and fluctuation amplitude. ; It satisfies the following formula 11.

[0063] (Formula 11) in, Indicates the number of pole pairs of the motor; This indicates the motor speed.

[0064] Among these, to more accurately adapt to changes in rotational speed, The following formula 12 is satisfied: (Formula 12) in, Indicates the base coefficient. ; Indicates the current time; This indicates the electrical angular velocity of the motor rotor; This represents a calibrable coefficient, which can be determined based on the motor's speed characteristics and is used for fine-tuning. To adapt to different working conditions.

[0065] Optional, and The value can be set according to actual needs, for example, , This application does not impose any limitations on this.

[0066] For example, two-phase α-axis current β-axis current The following formula 13 is satisfied: (Formula 13) in, Indicates the current in phase a; This represents the current in phase b. This represents the c-phase current.

[0067] S202. Based on the motor filter current and the observed values ​​of the motor's 6Kth rotor electrical angular velocity, determine the estimated value of the motor's 6Kth rotor electrical angle.

[0068] Among them, the 6Kth rotor electric angular velocity observation value is determined based on the motor rotor mechanical angular velocity observation value of the motor.

[0069] In some embodiments, the controller incorporates a built-in self-feedback phase-locked loop (PLL) module. In this case, the controller can input the motor filter current and observed rotor electrical angular velocity values ​​into the PLL module to obtain the motor's rotor phase deviation signal output by the PLL module. Subsequently, the PLL module can output the 6Kth order rotor electrical angle estimates of the motor based on the rotor phase deviation signal. The specific method for determining the 6Kth order rotor electrical angle estimates of the motor can be referred to the description in the following embodiments, and will not be repeated here.

[0070] S203. Based on the estimated value of the 6Kth rotor electrical angle and the motor current in the two-phase rotating coordinate system, determine the estimated value of the 6Kth harmonic current of the motor.

[0071] In some embodiments, the controller incorporates a d-axis current resolver and a q-axis current resolver. In this case, the controller can filter the current after the complex filter. and current By performing coordinate transformation, the motor current (i.e., the d-axis current) in the two-phase rotating coordinate system (hereinafter referred to as the dq-axis coordinate system) is obtained. and q-axis current After that, the controller can control the d-axis current. The estimated rotor electrical angle of the 6Kth order is input into the d-axis current decomposer to obtain the estimated d-axis 6Kth harmonic current. Similarly, the controller can output the q-axis current... The estimated rotor electrical angle of the 6Kth order is input into the q-axis current decomposer to obtain the estimated q-axis 6Kth harmonic current. The specific methods for calculating the estimated 6Kth harmonic current of the motor by the d-axis current decomposer and the q-axis current decomposer can be found in the following embodiments, and will not be repeated here.

[0072] For example, the motor current in the dq axis coordinate system satisfies the following formula 14.

[0073] = (Formula 14) in, Represents the d-axis current; Represents the q-axis current; This represents the filtered α-axis current; This represents the filtered β-axis current; Indicates the electrical angle of the motor rotor. It satisfies the following formula 15.

[0074] (Formula 15) in, Indicates the mechanical angle of the motor rotor; This indicates the number of pole pairs of the motor.

[0075] S204. Based on the estimated value of the 6Kth harmonic current, suppress the incoming harmonic current of the motor.

[0076] In some embodiments, the controller can determine the compensation voltage corresponding to the sixth harmonic current on the target axis based on the estimated value of the sixth harmonic current on the target axis, and suppress the harmonic current of the motor based on the compensation voltage.

[0077] For example, a compensation network (also called a voltage compensation network / voltage compensator) is deployed in the controller. Based on this, the controller can input the estimated 6th harmonic current on the target axis into the compensation network to obtain the compensation voltage corresponding to the 6th harmonic current on the target axis. Then, the compensation voltage corresponding to the 6th harmonic current on the target axis is superimposed on the reference voltage output by the current regulator. After inverse coordinate transformation, the voltage command in the αβ coordinate system is obtained and finally input to the space vector pulse width modulation (SVPWM) module to generate a switching drive signal, thereby realizing the closed-loop current control of the system.

[0078] The compensation network is used to represent the correspondence between harmonic current and the compensation voltage when harmonic current is suppressed. The target axes include the direct axis (d-axis) and the quadrature axis (q-axis).

[0079] In this embodiment, the compensation network adopts a fully connected neural network structure, comprising two input nodes, one output node, and two hidden layers; wherein the number of neurons in the two hidden layers are 8 and 4, respectively. The compensation network includes a d-axis compensation network and a q-axis compensation network. The network parameters of the compensation network are obtained by training the network parameters by using simulation models (such as Simulink simulation models) to obtain the required injected harmonic voltage data for different current harmonics (phase angle and amplitude).

[0080] In one example, Figure 3 This is a schematic diagram of the structure of a d-axis voltage compensation network provided in one embodiment of this application. Figure 3 As shown, the d-axis voltage compensation network includes an input layer, a hidden layer, and an output layer. The controller can estimate the 6Kth harmonic current of the d-axis output from the d-axis current decomposer. Inputting the d-axis voltage compensation network yields the d-axis compensation voltage output by the network. ).

[0081] In one example, Figure 4 This is a schematic diagram of the structure of a q-axis voltage compensation network provided in an embodiment of this application. Figure 4 As shown, the q-axis voltage compensation network includes an input layer, a hidden layer, and an output layer. The controller can estimate the 6Kth harmonic current of the q-axis output from the q-axis current decomposer. Inputting the q-axis voltage compensation network yields the q-axis compensation voltage output by the network. ).

[0082] For example, Figure 5 This is a schematic diagram illustrating a strategy for suppressing harmonic currents in a motor, provided as an embodiment of this application. Taking an IPMSM motor as an example, as... Figure 5 As shown, the three-phase current of the IPMSM , and After the Clarke transformation (i.e., the abc-αβ coordinate transformation), the current in the two-phase stationary coordinate system is obtained. and .after, and Mechanical angle with motor rotor The current in the dq-axis coordinate system is obtained through the αβ-dq transformation (also known as the inverse Park transformation). and Then, the control strategy module will input the direct-axis given current i*d and the quadrature-axis given current i*q, as well as... The input current regulator is used for adjustment, and the output reference voltage is adjusted. and reference voltage At the same time, and And the estimated value of the 6Kth harmonic current along the d-axis. Estimated 6K harmonic current along the q-axis The input is fed into the harmonic current regulator to obtain the d-axis compensation voltage. and q-axis compensation voltage Then, the compensation voltage will be... Superimposed on reference voltage Above, and will compensate voltage Superimposed on reference voltage Proceed to the next step. Afterwards, the compensation voltage will be... With reference voltage d-axis superimposed voltage and compensation voltage With reference voltage The superimposed voltages along the q-axis are transformed by the dq-αβ transformation to obtain the voltages in the αβ coordinate system. and Finally, and The input is sent to the SVPWM module to generate the switching drive signal for the three-phase inverter, controlling the inverter to output a specific voltage vector to the PMSM to drive the motor. Simultaneously, the motor's rotor mechanical angle is fed back from the motor. The angular velocity ω is provided to the coordinate transformation module in real time to ensure the accuracy of the transformation and form a complete current closed-loop control.

[0083] Based on the above technical solution, this application first filters the specific frequency band of the 6K pulse rectification in a two-phase stationary coordinate system, which can extract harmonic features with high fidelity without interfering with the fundamental wave control. Then, the 6Kth order electrical angular velocity is calculated using the existing rotor mechanical angular velocity of the motor to ensure real-time synchronization between frequency tracking and speed changes. On this basis, the 6Kth order rotor electrical angle is reconstructed by combining the filtered current, and the periodic AC harmonics are converted into easily processed DC components in the corresponding 6K rotating coordinate system, realizing the decoupling and separation of harmonics and the fundamental wave. Finally, harmonic suppression is implemented based on the accurate 6Kth order harmonic current estimate, realizing the effective suppression of specific order current harmonics under varying operating conditions, thereby reducing motor noise caused by harmonic currents.

[0084] In one optional implementation, S202 may specifically include: Step a: Determine the rotor phase deviation signal of the motor based on the motor filter current.

[0085] In some embodiments, the controller can input the motor filter current into the phase error detector in the phase-locked loop to obtain the rotor phase deviation signal.

[0086] For example, the controller incorporates a phase-locked loop (i.e., a self-feedback PLL module). The phase-locked loop includes a phase error detector and a proportional-integral (PI) controller. Based on this, the controller can process the filtered... , The harmonic current is input into the phase error detector in the phase-locked loop to obtain the rotor phase deviation signal. .

[0087] Taking the 6th harmonic current as an example, the rotor phase deviation signal The following formula 16 is satisfied: (Formula 16) Where k represents the gain coefficient / proportion coefficient; This indicates the actual electrical angle of the motor; This represents the electrical angle estimate (or phase angle estimate) of the 6th harmonic current.

[0088] because and The increase and decrease patterns are the same, therefore the error signal can be... Linearization is represented as: (Formula 17) in, This represents the estimated electrical angle of the motor.

[0089] Step b: Based on the rotor phase deviation signal, determine the baseline estimate of the 6Kth rotor electrical angular velocity of the motor.

[0090] In some embodiments, such as Figure 6 As shown, in the PI controller This represents the proportional gain, used to improve the system's response speed. This represents the integral gain, used to eliminate steady-state phase error; This represents the integral operator (i.e., integration operation). Based on this, the rotor phase deviation signal... The input is a PI controller, which is used to analyze the rotor phase deviation signal. By adjusting the ratio, the proportional term is obtained. Meanwhile, the PI controller monitors the rotor phase deviation signal. Perform integral adjustment to obtain the integral term. The proportional and integral terms are added together to obtain the baseline estimate of the electric angular velocity (i.e., + ).

[0091] Step c: Determine the estimation deviation feedback compensation value based on the estimation deviation between the 6Kth rotor electric angular velocity observation value and the previous estimate of the 6Kth rotor electric angular velocity.

[0092] In some embodiments, the controller may determine the estimated deviation feedback compensation value based on the estimated deviation, the rotor phase deviation signal, and the feedback compensation coefficient.

[0093] For example, such as Figure 6 As shown, The observed values ​​of the rotor electric angular velocity for the 6th harmonic ( ); This represents the previous estimate of the 6th harmonic rotor electric angular velocity; the estimation deviation is... and The difference between them; This represents the feedback compensation coefficient. Based on this, the controller can add the product of the estimated deviation and the feedback compensation coefficient to the rotor phase deviation signal to obtain the estimated deviation feedback compensation value.

[0094] Step d: Based on the baseline estimate and the estimation deviation feedback compensation value, determine the current estimate of the rotor electric angular velocity for the 6Kth cycle.

[0095] In some embodiments, such as Figure 6 As shown, the controller can calculate the sum between the baseline estimate and the estimation deviation feedback compensation value, and then pass the sum through an integrator. The estimated values ​​of the rotor electric angular velocity were obtained in six trials. .

[0096] Step e: Based on the current estimate, determine the estimated rotor electrical angle for the 6Kth time.

[0097] In some embodiments, the controller can use the current estimated value The estimated value of the rotor electrical angle was determined to be 6 times.

[0098] In some embodiments, such as Figure 6 As shown, the phase-locked loop can estimate the current value. Combination and s The input terminal is recalculated. until ,at this time It is completely synchronized with the phase of the input signal.

[0099] Based on the above technical solution, this application constructs a phase closed-loop adjustment mechanism for a phase-locked loop (PLL) by extracting the rotor phase deviation signal using the filtered 6K harmonic current in a two-phase stationary coordinate system. This effectively ensures precise synchronization between the harmonic rotating coordinate system and the actual 6K harmonic vector. Simultaneously, by introducing the observed 6K rotor electrical angular velocity derived from the motor's mechanical speed as a feedforward reference, the capture range of the phase loop is significantly reduced, enabling the system to quickly relock under variable speed and acceleration / deceleration conditions, avoiding the problem of easy lockout in traditional pure PLLs. Furthermore, the feedback compensation mechanism corrects the deviation between the observed and estimated electrical angular velocity values ​​in real time, suppressing model errors caused by filter phase shift, parameter changes, and integral drift, further improving the steady-state accuracy and robustness of the estimation.

[0100] In one optional implementation, S203 may specifically include: the controller can substitute the estimated value of the 6Kth rotor electrical angle into the first target mathematical model to obtain a second target mathematical model. Then, with the goal of minimizing the deviation between the actual value and the estimated value of the 6Kth harmonic current, the controller performs parameter learning on the second target mathematical model to obtain a third target mathematical model, and determines the 6Kth harmonic current estimated by the third target mathematical model as the estimated value of the 6Kth harmonic current.

[0101] The first objective mathematical model is used to estimate the 6Kth harmonic current in the motor current under a two-phase rotating coordinate system.

[0102] In this embodiment, the principle of harmonic current suppression is as follows: In a pulse width modulation (PWM) inverter, a dead time is required to prevent the DC bus from short-circuiting due to the simultaneous conduction of the upper and lower switches on the same bridge arm. However, the introduction of dead time will cause voltage distortion and energy loss, which will significantly affect the motor's operating performance, especially under high-speed conditions.

[0103] During the dead time, the output voltage is determined by the direction of the phase current, rather than the ideal switching state of the switching device. (Definition) Given the equivalent voltage loss of the switching devices (related to turn-on / turn-off delay, forward voltage drop, and diode forward voltage drop), the average voltage error of phase a within one PWM cycle is... It can be represented as: (Formula 18) in, Indicates the current in phase a; Indicates the equivalent loss voltage; Represents a symbolic function. The calculation formula is shown in Formula 19 below.

[0104] (Formula 19) Similarly, the average voltage error of phase b Average voltage error of phase c They can be represented as: (Formula 20) (Formula 21) in, This represents the average voltage error of phase b. This represents the average voltage error of phase c; This represents the phase b current. This represents the c-phase current.

[0105] Generally, the voltage error introduced by the dead-zone effect can be expressed in a three-phase stationary coordinate system. However, due to the nonlinear voltage disturbance caused by the dead-zone effect, it is difficult to accurately compensate for it directly in the three-phase stationary coordinate system. Therefore, the voltage error is usually transformed into a synchronous two-phase rotating coordinate system (i.e., the dq coordinate system) to achieve more effective control and compensation.

[0106] In the dq coordinate system, the voltage error caused by the dead zone effect can be expressed as: (Formula 22)

[0107] in, Indicates the d-axis voltage error; Indicates the q-axis voltage error; This represents the angle between the current vector and the q-axis in the dq coordinate system. This indicates the electrical angular velocity of the motor rotor; The harmonic order is represented. This indicates that the dead zone effect in the dq coordinate system is mainly manifested as 6th and multiples of the 6th harmonic disturbances, with the 6th harmonic being the most significant influencing component. Indicates time.

[0108] From the voltage error model described above (i.e., Equation 22), it can be seen that the dead-time effect and inverter nonlinearity in the dq coordinate system are mainly manifested as the 6th harmonic of the output voltage. Combining the above formula, taking the 6th harmonic as an example, the 6th harmonic current on the dq axis caused by inverter nonlinearity can be derived. , It can be represented as: (Formula 23) (Formula 24) (Formula 25) in, The harmonic phase angle is expressed as satisfying formula 24 above; The harmonic impedance is represented by formula 25 above; Indicates stator resistance. This represents the d-axis inductance of the PMSM; This represents the d-axis and q-axis inductance of the PMSM.

[0109] In summary, the main impact of the dead-zone effect on the voltage and current of a PMSM motor is the introduction of 6th harmonic and multiples thereof, which are related to the motor speed. Therefore, the impact of the dead-zone effect can be mitigated by filtering out (suppressing) the 6kth harmonic in the current, thereby improving system control performance. However, voltage source inverters typically do not have independent voltage sensors to detect the inverter output voltage, making it impossible to directly compensate for harmonics in the output voltage through fitting. Therefore, it is necessary to eliminate voltage harmonics by fitting the current harmonics.

[0110] In some embodiments, the first target mathematical model represents the current estimate on the target axis, which is equal to the sum of the actual fundamental current value on the target axis and the estimated 6K harmonic current value on the target axis; the actual fundamental current value on the target axis is extracted from the motor current in a two-phase rotating coordinate system. Based on this, the controller can perform parameter learning on the second target mathematical model with the objective of minimizing the deviation between the motor current in the two-phase rotating coordinate system and the current output by the second target mathematical model, to obtain the third target mathematical model.

[0111] In this embodiment of the application, the first target mathematical model (i.e., the d-axis current resolver and q-axis current resolver mentioned above) is used to represent the current estimate on the target axis, which is equal to the sum of the true value of the fundamental current on the target axis and the estimated value of the 6Kth harmonic current on the target axis.

[0112] The estimated 6K harmonic current on the direct axis is the sum of the first and second products; the estimated 6K harmonic current on the quadrature axis is the sum of the third and fourth products.

[0113] The first product is the product of the first direct-axis coefficient and the cosine term of the 6Kth rotor electrical angle estimate; the second product is the product of the second direct-axis coefficient and the sine term of the 6Kth rotor electrical angle estimate; the third product is the product of the first quadrature-axis coefficient and the cosine term of the 6Kth rotor electrical angle estimate; and the fourth product is the product of the second quadrature-axis coefficient and the negative value corresponding to the sine term of the 6Kth rotor electrical angle estimate. For specific details, please refer to the descriptions of the d-axis and q-axis current resolvers below.

[0114] For example, Figure 7 and Figure 8 Schematic diagrams of the d-axis current resolver and the q-axis current resolver are shown respectively.

[0115] like Figure 7 As shown, the d-axis estimated current can be expressed as: (Formula 26) in, This represents the input vector of the d-axis current resolver; This represents the weight vector of the d-axis current resolver; This represents the phase angle of the 6th harmonic current; where, the estimated value of the DC component on the d-axis is... ; Estimated value of the 6th harmonic current along the d-axis .

[0116] In this embodiment, the weight vector is calculated using the least mean square algorithm. The solution aims to minimize the error between the actual current and the estimated current along the d-axis in the synchronous coordinate system. Here, the error between the actual current and the estimated current along the d-axis is defined as... for: (Formula 27) Where k represents the sampling time; Indicates the actual current along the d-axis; This indicates the estimated current along the d-axis.

[0117] In this embodiment of the application, the weight vector The update rule can be expressed as: (Formula 28) in, This represents the weight vector of the q-axis current decomposer at time k; This represents the weight vector of the q-axis current decomposer at time k-1; This represents the learning rate of the d-axis current resolver; This represents the current error between the actual current along the d-axis and the estimated current along the d-axis. Let k represent the input vector at time k.

[0118] In this embodiment of the application, the weight vector middle The initial value is a given reference current. , and The initial value is 0.

[0119] The learning rate of the current resolver can be determined based on the electric angular velocity of the motor. For example, the learning rate... It satisfies the following formulas 29 and 30.

[0120] (Formula 29) (Formula 30) in, This represents the learning rate at time k. ; This represents the learning rate at time k-1; This represents the electric angular velocity of the motor rotor at time k; Indicates calibration adjustment factor Specifically, such as Figure 7 As shown, the controller incorporates a PLL module and an Adaptive Gradient Descent (Adp-GD) module. The controller can process the filtered... , Harmonic currents (i.e., i) β6 and i α6 and electric angular velocity In the input PLL, the PLL uses a closed-loop control algorithm (such as...) based on the input signal. Figure 6 ) calculate the current time. Then, the output of the PLL will be... Input into the d-axis current resolver to generate sinusoidal components. Sum and cosine components Then, the d-axis current resolver utilizes the input vector For the input vector and By performing a weighted summation (as in Formula 26 above), the estimated d-axis current is obtained. and the actual current of the d-axis Current estimation with d-axis Compare and calculate current error Then, the current error... Input into the Adp-GD module. The Adp-GD module can adjust the current error... and the current input vector The weight vector is updated according to a pre-defined adaptive algorithm (such as gradient descent). This forms a closed-loop regulation and control, enabling Approaching Thus achieving High-precision tracking.

[0121] Similarly, such as Figure 8 As shown, the q-axis estimated current can be expressed as: (Formula 31) in, This represents the input vector of the q-axis current resolver; This represents the weight vector of the q-axis current resolver; This represents the phase angle of the 6th harmonic current; where, the estimated value of the DC component on the q-axis is... ; Estimated 6th harmonic current along the q-axis .

[0122] In this embodiment, the weight vector is calculated using the least mean square algorithm. The solution aims to minimize the error between the actual q-axis current and the estimated q-axis current in the synchronous coordinate system. Here, the error between the actual q-axis current and the estimated q-axis current is defined. for: (Formula 32) Where k represents the sampling time; This represents the actual current along the q-axis. This indicates the q-axis estimated current.

[0123] In this embodiment of the application, the weight vector The update rule can be expressed as: (Formula 33) in, This represents the q-axis current decomposer weight vector at time k; This represents the weight vector of the q-axis current decomposer at time k-1; This represents the learning rate of the q-axis current resolver (the same as the learning rate of the d-axis current resolver). This represents the current error between the actual q-axis current and the estimated q-axis current. This represents the input vector of the q-axis current resolver at time k.

[0124] In this embodiment of the application, the weight vector middle The initial value is a given reference current. , and The initial value is 0.

[0125] Specifically, compared with the above Figure 7 The principle of the d-axis current resolver is the same. For example... Figure 8 As shown, the controller can filter the... , Harmonic currents (i.e., i) β6 and i α6 and electric angular velocity In the input PLL, the PLL uses a closed-loop control algorithm (such as...) based on the input signal. Figure 6 ) calculate the current time. Then, the output of the PLL will be... The input is sent to the q-axis current resolver to generate a sinusoidal component. Sum and cosine components Then, the q-axis current resolver uses the input vector The input vector is weighted and summed (as shown in Equation 31 above) to obtain the q-axis estimated current. and the actual q-axis current Current estimation with q-axis Compare and calculate current error Then, the current error... Input into the Adp-GD module. The Adp-GD module can adjust the current error... and the current input vector The weight vector is updated according to a pre-defined adaptive algorithm (such as gradient descent). This forms a closed-loop regulation and control, enabling Approaching This enables control of the rotor position. High-precision tracking.

[0126] Based on the above technical solution, this application utilizes the accurately estimated 6Kth rotor electrical angle as a transformation reference to encapsulate the dynamic characteristics of the 6Kth harmonic current in a two-phase rotating coordinate system within a first objective mathematical model. Using the actually observed harmonic current as a monitoring signal, the model parameters are iteratively updated online by minimizing the estimation deviation (i.e., obtaining the third objective mathematical model). This method no longer relies solely on fixed motor electrical parameters but instead uses a self-correcting approach to approximate the dynamics of the actual physical system, thereby adaptively compensating for the effects of digital control delay, inverter nonlinearity, and unmodeled dynamics.

[0127] This application also provides a harmonic current suppression device for an electric motor; please refer to [link to relevant documentation]. Figure 9 The harmonic current suppression device for a motor provided in this application embodiment includes: a filtering unit 901, a first determining unit 902, a second determining unit 903, and a control unit 904. The filtering unit 901 is used to perform... Figure 2 In the illustrated method, step S201 is performed by the first determining unit 902. Figure 2 In the illustrated method, step S202 is performed by the second determining unit 903. Figure 2 In the illustrated method, step S203 is executed by control unit 904. Figure 2 The illustrated method includes step S204.

[0128] like Figure 10 As shown in the embodiments of this application, an electronic device includes, but is not limited to, a processor 1001 and a memory 1002.

[0129] The memory 1002 described above is used to store the executable instructions of the processor 1001. It is understood that the processor 1001 is configured to execute instructions to implement the harmonic current suppression method for the motor in the above embodiment.

[0130] It should be noted that those skilled in the art will understand that Figure 10 The electronic device structure shown does not constitute a limitation on the electronic device; the electronic device may include, but is not limited to, other electronic devices. Figure 10 This may indicate more or fewer components, or a combination of certain components, or a different arrangement of components.

[0131] The processor 1001 is the control center of the electronic device. It connects various parts of the electronic device via various interfaces and lines. By running or executing software programs and / or modules stored in the memory 1002, and by calling data stored in the memory 1002, it performs various functions and processes data, thereby providing overall monitoring of the electronic device. The processor 1001 may include one or more processing units. Optionally, the processor 1001 may integrate an application processor and a modem processor. The application processor mainly handles the operating system, user interface, and applications, while the modem processor mainly handles wireless communication. It is understood that the modem processor may not be integrated into the processor 1001.

[0132] The memory 1002 can be used to store software programs and various data. The memory 1002 may primarily include a program storage area and a data storage area. The program storage area may store the operating system, application programs required by at least one functional module (such as a determination unit, processing unit, etc.), etc. Furthermore, the memory 1002 may include high-speed random access memory and may also include non-volatile memory. For example, non-volatile memory may include at least one disk storage device, flash memory device, or other non-volatile solid-state storage device.

[0133] In an exemplary embodiment, a computer-readable storage medium including instructions is also provided, such as a memory 1002 including instructions, which can be executed by a processor 1001 of an electronic device to implement the methods in the above embodiments.

[0134] Optionally, the computer-readable storage medium may be a non-transitory computer-readable storage medium, such as a read-only memory (ROM), random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device.

[0135] In an exemplary embodiment, this application also provides a computer program product including one or more instructions, which can be executed by the processor 1001 of an electronic device to perform the methods described above.

[0136] It should be noted that when one or more instructions in the computer-readable storage medium or computer program product are executed by the processor of an electronic device, they implement the various processes of the above method embodiments and achieve the same technical effect as the above method. To avoid repetition, they will not be described again here.

[0137] Through the above description of the embodiments, those skilled in the art can clearly understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0138] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another apparatus, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0139] The units described as separate components may or may not be physically separate. A component shown as a unit can be one or more physical units; that is, it can be located in one place or distributed in multiple different locations. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0140] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0141] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, essentially, or the parts that contribute to the prior art, or all or part of the technical solutions, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0142] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for suppressing harmonic current in a motor, characterized in that, The harmonic current suppression method for the motor includes: The motor current in a two-phase stationary coordinate system is filtered to obtain the motor filtered current; wherein, the filtering is used to extract the 6K pulse rectified harmonics; Based on the motor filter current and the observed 6Kth rotor electrical angular velocity of the motor, the estimated value of the 6Kth rotor electrical angle of the motor is determined; wherein, the observed 6Kth rotor electrical angular velocity is determined based on the observed value of the motor rotor mechanical angular velocity; Based on the estimated value of the 6Kth rotor electrical angle and the motor current in the two-phase rotating coordinate system, the estimated value of the 6Kth harmonic current of the motor is determined. Based on the estimated 6Kth harmonic current, the incoming harmonic current of the motor is suppressed.

2. The method for suppressing harmonic currents in a motor according to claim 1, characterized in that, The process of determining the estimated value of the 6Kth rotor electrical angle of the motor based on the motor filter current and the observed values ​​of the motor's 6Kth rotor electrical angular velocity includes: Based on the motor filter current, the rotor phase deviation signal of the motor is determined; Based on the rotor phase deviation signal, a baseline estimate of the 6Kth rotor electrical angular velocity of the motor is determined; Based on the estimation deviation between the 6K observed rotor electric angular velocity values ​​and the previous estimated value of the 6K observed rotor electric angular velocity, an estimation deviation feedback compensation value is determined. Based on the baseline estimate and the estimation deviation feedback compensation value, the current estimate of the rotor electric angular velocity for the 6Kth cycle is determined; Based on the current estimate, the estimated rotor electrical angle for the 6Kth time is determined.

3. The method for suppressing harmonic currents in a motor according to claim 2, characterized in that, The determination of the estimation deviation feedback compensation value based on the estimation deviation between the 6Kth rotor electrical angular velocity observation value and the previous estimated value of the 6Kth rotor electrical angular velocity includes: The estimated deviation feedback compensation value is determined based on the estimated deviation, the rotor phase deviation signal, and the feedback compensation coefficient.

4. The method for suppressing harmonic currents in a motor according to claim 2, characterized in that, The determination of the baseline estimate of the 6Kth rotor electrical angular velocity of the motor based on the rotor phase deviation signal includes: The rotor phase deviation signal is input into the proportional-integral controller in the phase-locked loop to obtain the reference estimate output by the proportional-integral controller.

5. The method for suppressing harmonic currents in a motor according to claim 2, characterized in that, The step of determining the rotor phase deviation signal of the motor based on the motor filter current includes: The motor filter current is input into the phase error detector in the phase-locked loop to obtain the rotor phase deviation signal.

6. The method for suppressing harmonic currents in a motor according to any one of claims 1-5, characterized in that, The process of determining the estimated value of the 6Kth harmonic current of the motor based on the estimated value of the 6Kth rotor electrical angle and the motor current in the two-phase rotating coordinate system includes: Substituting the estimated 6Kth rotor electrical angle into the first objective mathematical model yields the second objective mathematical model; the first objective mathematical model is used to estimate the 6Kth harmonic current in the motor current under the two-phase rotating coordinate system. With the goal of minimizing the deviation between the true value and the estimated value of the 6Kth harmonic current, the second objective mathematical model is subjected to parameter learning to obtain the third objective mathematical model. The 6Kth harmonic current estimated by the third objective mathematical model is determined as the estimated value of the 6Kth harmonic current.

7. The method for suppressing harmonic currents in a motor according to claim 6, characterized in that, The first target mathematical model is used to represent the current estimate on the target axis, which is equal to the sum of the actual value of the fundamental current on the target axis and the estimated value of the 6Kth harmonic current on the target axis; the target axis is a direct axis and a quadrature axis; the actual value of the fundamental current on the target axis is extracted from the motor current in the two-phase rotating coordinate system; The goal is to minimize the deviation between the actual value and the estimated value of the 6Kth harmonic current. The second objective mathematical model is then subjected to parameter learning to obtain a third objective mathematical model, which includes: With the goal of minimizing the deviation between the motor current in the two-phase rotating coordinate system and the current output by the second target mathematical model, the parameters of the second target mathematical model are learned to obtain the third target mathematical model.

8. The method for suppressing harmonic currents in a motor according to claim 7, characterized in that, The estimated 6K harmonic current on the direct axis is the sum of the first and second products; the estimated 6K harmonic current on the quadrature axis is the sum of the third and fourth products. The first product is the product between the first straight-axis coefficient and the cosine term of the 6Kth rotor electrical angle estimate; The second product is the product between the second direct axis coefficient and the sine term of the estimated 6K rotor electrical angles; The third product is the product between the first cross-axis coefficient and the cosine term of the 6Kth order rotor electrical angle estimate; The fourth product is the product between the second cross-axis coefficient and the negative value corresponding to the sine term of the 6Kth rotor electrical angle estimate.

9. The method for suppressing harmonic currents in a motor according to claim 7, characterized in that, The suppression of the incoming harmonic current of the motor based on the estimated 6Kth harmonic current includes: Based on the estimated value of the 6th harmonic current on the target axis, determine the compensation voltage corresponding to the 6th harmonic current on the target axis; Based on the compensation voltage, the harmonic current of the motor is suppressed.

10. The method for suppressing harmonic currents in a motor according to claim 9, characterized in that, The step of determining the compensation voltage corresponding to the 6th harmonic current on the target axis based on the estimated value of the 6th harmonic current on the target axis includes: The estimated value of the 6th harmonic current on the target axis is input into the compensation network to obtain the compensation voltage corresponding to the 6th harmonic current on the target axis. The compensation network is used to represent the correspondence between harmonic current and the compensation voltage when harmonic current is suppressed.

11. The method for suppressing harmonic currents in a motor according to claim 1, characterized in that, The filtering of the motor current in the two-phase stationary coordinate system to obtain the filtered motor current includes: The motor current in the two-phase stationary coordinate system is input into a complex filter to obtain the filtered motor current after filtering by the complex filter. The center frequency of the complex filter is the frequency corresponding to the 6K pulse rectified harmonic, and the cutoff frequency is positively correlated with the observed value of the motor rotor electric angular velocity; the cutoff frequency is used to define the bandpass frequency range.

12. A vehicle, characterized in that, The vehicle employs the harmonic current suppression method for the motor as described in any one of claims 1-11 to suppress harmonic current.

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