CN113131820B - Method and device for analyzing periodic errors of permanent magnet synchronous motor - Google Patents

Abstract

The invention discloses a method and a device for analyzing periodic errors of a permanent magnet synchronous motor, wherein the method comprises the following steps: determining a current angle signal, a preset harmonic frequency and a preset fundamental frequency of the permanent magnet synchronous motor in a constant rotating speed state; calculating an initial sine function corresponding to the current angle signal; calculating a complex vector function corresponding to the initial sine function; generating a first target harmonic current frequency through a first coordinate transformation path and a second target harmonic current frequency through a second coordinate transformation path; and analyzing and verifying the periodic error of the permanent magnet synchronous motor through a preset periodic error analysis algorithm according to the preset fundamental wave frequency, the preset harmonic frequency, the first target harmonic current frequency and the second target harmonic current frequency. The periodic error analysis of the permanent magnet synchronous motor is beneficial to timely compensating the periodic error on line according to the known reason of the periodic error, so that the periodic error is improved, and the online compensation precision is improved.

Description

A method and device for analyzing periodic error of permanent magnet synchronous motor

technical field

The invention relates to the technical field of permanent magnet synchronous motors, in particular to a method and device for analyzing periodic errors of permanent magnet synchronous motors.

Background technique

In order to realize the energy conversion of the synchronous motor, a DC magnetic field needs to be set up, and a DC current is generated through the DC magnetic field, which is called the excitation current of the motor. According to the supply method of the excitation current, any generator that obtains the excitation current from other power sources is called It is a permanent magnet synchronous motor.

In the field-oriented control of the permanent magnet synchronous motor, the signal detection information of the magnetic pole position of the motor rotor is an important feedback information of the motor control system, which reflects the motion state of the motor in real time and directly affects the performance of the motor control system. As a common position sensor, resolver (Resolver) has good robustness, high reliability, can suppress common mode noise, and is also suitable for working environments with harsh conditions. Therefore, resolvers are widely used in the detection of permanent magnet synchronization. Motor rotor pole position signal for the motor. However, the resolver itself has nonlinear characteristics, and the resolver has non-ideal factors such as rotor eccentricity, non-orthogonal rotating sine and cosine windings, and asymmetric conditioning circuits during the mechanical installation process of the resolver, which cause the rotor magnetic pole position signal of the motor to inevitably appear The periodic error of different frequencies affects the control performance of the permanent magnet synchronous motor. Therefore, it is very important to systematically analyze the periodic error of the permanent magnet synchronous motor.

At present, it is only mentioned in the prior art that there will be periodic errors in the process of detecting the magnetic pole position signal of the motor rotor by the resolver. The value signal is used to compensate the periodic error online. However, because the reason for the periodic error generated by the resolver in the specific application is not considered in a targeted manner, the result of the online compensation of the periodic error may be inaccurate.

SUMMARY OF THE INVENTION

In view of this, the embodiment of the present invention provides a method for analyzing the periodic error of a permanent magnet synchronous motor, so as to solve the reason that the periodic error generated by the resolver in the specific application is not considered in the prior art. The result of online compensation of periodic errors is not accurate enough.

According to a first aspect, an embodiment of the present invention provides a method for analyzing the periodic error of a permanent magnet synchronous motor, including the following steps:

Determine the current angle signal, the preset harmonic frequency and the preset fundamental frequency of the permanent magnet synchronous motor at a constant speed;

calculating an initial sine function corresponding to the current angle signal according to the current angle signal, the preset harmonic frequency and the preset fundamental frequency;

During the coordinate transformation process of the current angle signal, the complex vector function corresponding to the initial sine function is calculated;

generating a first target harmonic current frequency through a first coordinate transformation path and generating a second target harmonic current frequency through a second coordinate transformation path according to the complex vector function and the preset fundamental frequency;

According to the preset fundamental frequency, the preset harmonic frequency, the first target harmonic current frequency and the second target harmonic current frequency, the period of the permanent magnet synchronous motor is analyzed and verified by a preset periodic error analysis algorithm sexual error.

With reference to the first aspect, in the first embodiment of the first aspect, the step of determining the current angle signal of the permanent magnet synchronous motor in a state of constant rotational speed includes:

Determine the initial angle signal of the permanent magnet synchronous motor under various rotational speed states;

According to the initial angle signal, the current angle signal of the permanent magnet synchronous motor in the state of constant rotational speed is determined.

In combination with the second embodiment of the first aspect, in the second embodiment of the first aspect, the determination of the current angle signal of the permanent magnet synchronous motor in a constant rotational speed state according to the initial angle signal is calculated by the following formula:

θ _e =K·θ _rdc , K=n _p /p _rdc

为k次谐波相位，θ_rdc为初始角度信号，ω_rdc为角频率；θ_e为当前角度信号，n_p为永磁同步电机极对数，p_rdc为旋变极对数，K为永磁同步电机极对数与旋变极对数的比值。Among them, e _h is the harmonic in the initial angle signal, k is the harmonic frequency, a _k is the k-th harmonic amplitude and

is the k-th harmonic phase, θ _rdc is the initial angle signal, ω _rdc is the angular frequency; θ _e is the current angle signal, n _p is the number of pole pairs of the permanent magnet synchronous motor, p _rdc is the number of resolver pole pairs, and K is the permanent The ratio of the number of pole pairs to the number of resolver pole pairs for a magnetic synchronous motor.

With reference to the first aspect, in the third embodiment of the first aspect, the initial sine corresponding to the current angle signal is calculated according to the current angle signal, the preset harmonic frequency and the preset fundamental frequency The function is calculated by the following formula:

J_n(λ_k)为调频指数为λ_k的n阶第一类贝塞尔函数，

θ_e为所述当前角度信号，ω_e为所述预设基波频率，λ为所述预设谐波频次，λ_k为所述永磁同步电机的正弦扰动幅值。in,

J _n (λ _k ) is the n-th order Bessel function of the first kind with a frequency modulation index of λ _k ,

θ _e is the current angle signal, ω _e is the preset fundamental frequency, λ is the preset harmonic frequency, and λ _k is the sinusoidal disturbance amplitude of the permanent magnet synchronous motor.

With reference to the first aspect, in the fourth embodiment of the first aspect, during the coordinate transformation process of the current angle signal, the formula for calculating the complex vector function corresponding to the initial sine function is as follows:

J _-n (λ _k )=(-1) ⁿ J _n (λ _k )

为所述复矢量函数。Wherein, θ _e is the current angle signal, ω _e is the preset fundamental frequency, λ is the preset harmonic frequency, λ _k is the sinusoidal disturbance amplitude of the permanent magnet synchronous motor,

is the complex vector function.

With reference to the first aspect, in a fifth implementation manner of the first aspect, according to the preset fundamental frequency, the preset harmonic frequency, the first target harmonic current frequency and the second target harmonic current frequency, Through the analysis and verification of the preset periodic error analysis algorithm, the periodic error of the permanent magnet synchronous motor is calculated by the following formula:

Let the preset fundamental frequency be ω _e , let the preset harmonic frequency λ be 0.5, let the first target harmonic current frequency be ω ₂ =λω _e =0.5ω _e , let the second target harmonic current frequency be ω ₁ =(2-λ)ω _e =1.5ω _e , and the current angle signal of the permanent magnet synchronous motor is a single-frequency disturbance of 0.5ω _e ,

为对应频率分量的相位，

ω_r1为PI调节器对应输入信号的频率，ω_r2为负载对应输入信号的频率，U_s为dq坐标系相电压幅值，当电流响应进入稳态后，PI调节器的直流输入分量为零，0.5ω_e频次电流谐波由u_dq直流分量经旋转矢量

产生。Among them, a _1.5 is the 1.5th order current amplitude, a ₁ is the 1st order current amplitude, a _0.5 is the 0.5th order current amplitude, _{k p} is the ratio of the PI regulator, ki is the integral coefficient of the PI regulator, Z _a is the equivalent impedance of phase A, K _PI is the equivalent gain of the PI regulator,

is the phase of the corresponding frequency component,

ω _r1 is the frequency of the input signal corresponding to the PI regulator, ω _r2 is the frequency of the input signal corresponding to the load, and U _s is the phase voltage amplitude of the dq coordinate system. When the current response enters a steady state, the DC input component of the PI regulator is zero. , the 0.5ω _e frequency current harmonics are rotated by the u _dq DC component via the rotation vector

produce.

With reference to the first aspect, in a sixth implementation manner of the first aspect, according to the preset fundamental frequency, the preset harmonic frequency, the first target harmonic current frequency and the second target harmonic current frequency, Through the analysis and verification of the preset periodic error analysis algorithm, the periodic error of the permanent magnet synchronous motor is also calculated by the following formula:

Let the preset fundamental frequency be ω _e , let the preset harmonic frequency λ be 0.5, let the first target harmonic current frequency be ω ₂ =λω _e =0.5ω _e , let the second target harmonic current frequency be ω ₁ =(2-λ)ω _e =1.5ω _e , and the current angle signal of the permanent magnet synchronous motor is a single-frequency disturbance of 0.5ω _e ,

Wherein, k _i /ω _r1 <<k _p , a _1.5 is the 1.5th order current amplitude, a ₁ is the 1st order current amplitude, a _0.5 is the 0.5th order current amplitude, λ _k is the sine of the permanent magnet synchronous motor The perturbation amplitude, k _p is the ratio of the PI regulator.

According to a second aspect, an embodiment of the present invention provides a device for analyzing the periodic error of a permanent magnet synchronous motor, including:

A determination module, used to determine the current angle signal, the preset harmonic frequency and the preset fundamental frequency of the permanent magnet synchronous motor in a state of constant speed;

a first calculation module, configured to calculate the initial sine function corresponding to the current angle signal according to the current angle signal, the preset harmonic frequency and the preset fundamental frequency;

a second calculation module, configured to calculate the complex vector function corresponding to the initial sine function during the coordinate transformation process of the current angle signal;

A target harmonic current generation module is configured to generate a first target harmonic current frequency through a first coordinate transformation path and a second target harmonic current through a second coordinate transformation path according to the complex vector function and the preset fundamental frequency. wave current frequency;

An analysis and verification module for analyzing the preset periodic error analysis algorithm according to the preset fundamental frequency, preset harmonic frequency, the first target harmonic current frequency and the second target harmonic current frequency Verify the periodic error of a permanent magnet synchronous motor.

According to a third aspect, an embodiment of the present invention provides a permanent magnet synchronous motor control system, including:

The first axial current loop PI regulator is used for receiving the first axial current signal, and performing PI adjustment and control on the first axial current signal to output the first axial voltage signal;

The second axial current loop PI regulator is used for receiving the second axial current signal, and performing PI adjustment and control on the second axial current signal to output the second axial voltage signal;

a first coordinate converter, respectively connected to the first axial current loop PI regulator and the second axial current loop PI regulator;

a PWM modulator, connected to the first coordinate converter;

an inverter, connected with the PWM modulator;

a second coordinate converter, respectively connected to the first axial current loop PI regulator, the second axial current loop PI regulator and the first coordinate converter;

a current sensor, connected to the second coordinate converter and the inverter respectively;

a permanent magnet synchronous motor, connected with the current sensor;

a rotary transformer, connected with the permanent magnet synchronous motor;

an angle sine-cosine converter, connected with the resolver;

a processor connected to the permanent magnet synchronous motor, the processor including a computer program stored on a computer-readable storage medium, the computer program including program instructions, when the program instructions are executed by a computer, cause the computer to execute The steps of the method for analyzing the periodic error of the permanent magnet synchronous motor described in the first aspect or any embodiment of the first aspect.

According to a fourth aspect, an embodiment of the present invention provides a computer device, including: a memory and a processor, the memory and the processor are connected in communication with each other, the memory stores computer instructions, and the processor passes Executing the computer instructions causes the computer to execute the steps of the method for analyzing the periodic error of a permanent magnet synchronous motor described in the first aspect or any embodiment of the first aspect.

The technical solution of the embodiment of the present invention has the following advantages:

The invention provides a method and device for analyzing the periodic error of a permanent magnet synchronous motor, wherein the method includes: determining a current angle signal, a preset harmonic frequency and a preset fundamental frequency of the permanent magnet synchronous motor under a constant rotational speed state; According to the current angle signal, the preset harmonic frequency and the preset fundamental frequency, the initial sine function corresponding to the current angle signal is calculated; during the coordinate transformation process of the current angle signal, the complex vector function corresponding to the initial sine function is calculated; according to the complex vector function and the preset fundamental frequency, the first target harmonic current frequency is generated through the first coordinate transformation path and the second target harmonic current frequency is generated through the second coordinate transformation path; according to the preset fundamental frequency, preset harmonic frequency , the first target harmonic current frequency and the second target harmonic current frequency, and the periodic error of the permanent magnet synchronous motor is analyzed and verified by a preset periodic error analysis algorithm. Through the analysis of the periodic error of the permanent magnet synchronous motor, it is beneficial to timely compensate the periodic error online according to the known cause of the periodic error, thereby improving the periodic error and improving the accuracy of the online compensation.

Description of drawings

In order to illustrate the specific embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the specific embodiments or the prior art. Obviously, the accompanying drawings in the following description The drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

Fig. 1 is the flow chart of the analysis method of the periodic error of permanent magnet synchronous motor in the embodiment of the present invention;

2 is a schematic diagram of the corresponding relationship between the angle distortion of the permanent magnet synchronous motor and the frequency component of the current distortion in the embodiment of the present invention;

Fig. 3 is the harmonic current analysis block diagram of the permanent magnet synchronous motor in the embodiment of the present invention;

4 is a schematic diagram of the analysis result of the current harmonic content in the embodiment of the present invention;

Fig. 5 is the structural block diagram of the analyzing device of the periodic error of permanent magnet synchronous motor in the embodiment of the present invention;

6 is a schematic structural diagram of a permanent magnet synchronous motor control system in an embodiment of the present invention;

FIG. 7 is a schematic diagram of a hardware structure of a computer device in an embodiment of the present invention.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

An embodiment of the present invention provides a method for analyzing the periodic error of a permanent magnet synchronous motor, as shown in FIG. 1 , including the following steps:

Step S1: Determine the current angle signal, the preset harmonic frequency and the preset fundamental frequency of the permanent magnet synchronous motor in a state of constant rotational speed. The constant speed state here is the steady state of the permanent magnet synchronous motor, that is, the working state of the permanent magnet synchronous motor in the steady speed state. Specifically, the current angle signal in the above is the current electrical angle of the permanent magnet synchronous motor, and the current electrical angle is the electrical angle detected by the resolver, which represents the rotor magnetic pole position signal of the motor, and the current electrical angle can be represented by θ _e . The preset harmonic frequency is the frequency of the permanent magnet synchronous motor, which can be represented by λ. The preset harmonic frequency is an assumed harmonic frequency. For example, λ can represent the first harmonic, the second harmonic and the third harmonic. Wait. The preset fundamental frequency can be a preset frequency, which is also a hypothetical harmonic frequency, which can be represented by ω _e .

In a specific embodiment, in the process of executing the above step S1, the following steps may be specifically included:

The first step: determine the initial angle signal of the permanent magnet synchronous motor under various rotational speed states.

The various rotational speeds here include the initial angle signals of the permanent magnet synchronous motor in the high-speed state, the steady-speed state, and the low-speed state, and the initial angle signal can be represented by θ _rdc .

Step 2: According to the initial angle signal, determine the current angle signal of the permanent magnet synchronous motor in the state of constant speed.

Specifically, according to the initial angle signal, it is determined that the current angle signal of the permanent magnet synchronous motor in the state of constant speed is calculated by the following formula:

θ _e =K·θ _rdc , K=n _p / _prdc …………………………(2);

为k次谐波相位，θ_rdc为初始角度信号，ω_rdc为角频率；θ_e为当前角度信号，n_p为永磁同步电机极对数，p_rdc为旋变极对数，K为永磁同步电机极对数与旋变极对数的比值。因此，根据初始角度信号θ_rdc，可以确定永磁同步电机在恒定转速状态下的当前角度信号θ_e。Among them, e _h is the harmonic in the initial angle signal, k is the harmonic frequency, a _k is the k-th harmonic amplitude and

is the k-th harmonic phase, θ _rdc is the initial angle signal, ω _rdc is the angular frequency; θ _e is the current angle signal, n _p is the number of pole pairs of the permanent magnet synchronous motor, p _rdc is the number of resolver pole pairs, and K is the permanent The ratio of the number of pole pairs to the number of resolver pole pairs for a magnetic synchronous motor. Therefore, according to the initial angle signal θ _rdc , the current angle signal θ _e of the permanent magnet synchronous motor in the state of constant rotational speed can be determined.

Step S2: Calculate the initial sine function corresponding to the current angle signal according to the current angle signal, the preset harmonic frequency and the preset fundamental frequency.

In a specific embodiment, during the execution of the above step S2, it can be calculated by the following formula:

J_n(λ_k)为调频指数为λ_k的n阶第一类贝塞尔函数，

θ_e为当前角度信号，ω_e为预设基波频率，λ为预设谐波频率，λ_k为永磁同步电机的正弦扰动幅值。因此，上述中的sinθ_e为初始正弦函数。in,

J _n (λ _k ) is the n-th order Bessel function of the first kind with a frequency modulation index of λ _k ,

θ _e is the current angle signal, ω _e is the preset fundamental frequency, λ is the preset harmonic frequency, and λ _k is the sinusoidal disturbance amplitude of the permanent magnet synchronous motor. Therefore, sinθ _e in the above is the initial sine function.

Step S3: During the coordinate transformation process of the current angle signal, the complex vector function corresponding to the initial sine function is calculated.

In a specific embodiment, in the process of executing the above step S3, it is calculated by the following formula:

J _-n (λ _k )=(-1) ⁿ J _n (λ _k )………………………………………………(4);

为复矢量函数。上述公式(6)是对上述公式(5)进行电角度正弦值的级数分析，才进一步得到上式(6)对应的复矢量函数。Among them, θ _e is the current angle signal, ω _e is the preset fundamental frequency, λ is the preset harmonic frequency, λ _k is the sinusoidal disturbance amplitude of the permanent magnet synchronous motor,

is a complex vector function. The above formula (6) is based on the series analysis of the electrical angle sine value of the above formula (5), and then the complex vector function corresponding to the above formula (6) is further obtained.

Step S4: According to the complex vector function and the preset fundamental frequency, the first target harmonic current frequency is generated through the first coordinate transformation path and the second target harmonic current frequency is generated through the second coordinate transformation path. The first coordinate transformation is park transformation, and the second coordinate transformation is ipark transformation.

As shown in FIG. 2 , the preset fundamental frequency is ω _e , the complex vector function is the above formula (6), the first coordinate transformation path is ① in FIG. 2 , and the second coordinate transformation path is ② in FIG. 2 . The frequency of the first target harmonic current generated by the first coordinate transformation path is ω ₂ and the frequency of the second target harmonic current generated by the second coordinate transformation path is ω ₁ , where ω ₁ =(2-λ)ω _e , ω ₂ =λω _e .

Through the analysis of the above formula, due to the nonlinear characteristics of the resolver itself, and the non-ideal factors such as rotor eccentricity, non-orthogonal rotating sine and cosine windings, and asymmetry of the conditioning circuit during the mechanical installation of the resolver, the current electrical angle is in the coordinate transformation. When , the expression form is the complex vector function shown in the above formula (6). In view of J ₁ (λk), J _-1 (λ _k )...<<J ₀ (λ _k ), the main component of the harmonic current is determined by the fundamental frequency The current acts on the fundamental frequency rotation vector and the harmonic rotation vector in the Park transformation and the Ipark transformation, respectively. Considering the single-frequency disturbance in the position signal, it corresponds to the first coordinate transformation path ① and the second coordinate transformation path ② in Figure 2, respectively. However, the harmonics of other frequencies generated by the coordinate transformation of the harmonic current can be ignored, that is, the harmonic signal with the frequency λω _e in the electrical angle signal causes the harmonic frequencies of the three-phase current to be mainly λω _e and (2-λ)ω _e .

As shown in Figure 3, it is a block diagram of harmonic current analysis, ignoring factors such as switching tube nonlinearity and motor asymmetry, according to the first coordinate transformation path and the second coordinate transformation path in Figure 2, the quantitative expression of harmonic current can be obtained . Then, on this basis, the periodic error of the permanent magnet synchronous motor can be further analyzed and verified based on the following preset periodic error analysis algorithm.

Step S5: According to the preset fundamental frequency, the preset harmonic frequency, the first target harmonic current frequency and the second target harmonic current frequency, analyze and verify the periodic error of the permanent magnet synchronous motor through a preset periodic error analysis algorithm.

In a specific embodiment, in the process of executing the above step S5, it can be calculated by the following formula:

Let the preset fundamental frequency be ω _e , let the preset harmonic frequency λ be 0.5, let the first target harmonic current frequency be ω ₂ =λω _e =0.5ω _e , let the second target harmonic current frequency be ω ₁ =(2-λ)ω _e =1.5ω _e , taking the current angle signal of the permanent magnet synchronous motor as 0.5ω _e single-frequency disturbance,

为对应频率分量的相位，

为第一频率成分对应PI调节器与阻抗的第一相角差，

为第二频率成分对应PI调节器与阻抗的第二相角差，

为第一频率成分对应PI调节器与阻抗的第三相角差，

为第一频率成分对应PI调节器与阻抗的第四相角差，由负载阻抗角和PI调节器等效阻抗角之差决定。

ω_r1为PI调节器对应输入信号的频率，ω_r2为负载对应输入信号的频率，U_s为dq坐标系相电压幅值，当电流响应进入稳态后，PI调节器的直流输入分量为零，0.5ω_e频次电流谐波由u_dq直流分量经旋转矢量

产生。Among them, a _1.5 is the 1.5th order current amplitude, a ₁ is the 1st order current amplitude, a _0.5 is the 0.5th order current amplitude, _{k p} is the ratio of the PI regulator, ki is the integral coefficient of the PI regulator, Z _a is the equivalent impedance of phase A, K _PI is the equivalent gain of the PI regulator,

is the phase of the corresponding frequency component,

is the first phase angle difference between the PI regulator and the impedance corresponding to the first frequency component,

is the second phase angle difference between the PI regulator and the impedance corresponding to the second frequency component,

is the third phase angle difference between the PI regulator and the impedance corresponding to the first frequency component,

The fourth phase angle difference between the PI regulator and the impedance corresponding to the first frequency component is determined by the difference between the load impedance angle and the equivalent impedance angle of the PI regulator.

ω _r1 is the frequency of the input signal corresponding to the PI regulator, ω _r2 is the frequency of the input signal corresponding to the load, and U _s is the phase voltage amplitude of the dq coordinate system. When the current response enters a steady state, the DC input component of the PI regulator is zero. , the 0.5ω _e frequency current harmonics are rotated by the u _dq DC component via the rotation vector

produce.

Taking the motor rotor magnetic pole position signal harmonic as a 0.5ωe single-frequency disturbance as an example, the 0.5ωe frequency current harmonic and the 1.5ωe frequency current harmonic are generated by paths ① and ② in Figure 2, respectively. Among them, the amplitude expression of the 1.5ωe frequency current harmonics satisfies the above equation (7), the amplitude expression of the _0.5ωe frequency current harmonics satisfies the above equation (8), for the expression (7) The first term on the left side of the equation is the 1.5ωe frequency harmonic current component of the fundamental frequency current generated by path ②, and the second term is the 1.5ωe frequency harmonic current component generated by the 1.5ωe frequency harmonic current through path ①. The right side of the equation is Total 1.5ωe frequency harmonic current.

In a specific embodiment, the above-mentioned step S5 is also calculated by the following formula during the execution process:

Let the preset fundamental frequency be ω _e , let the preset harmonic frequency λ be 0.5, let the first target harmonic current frequency be ω ₂ =λω _e =0.5ω _e , let the second target harmonic current frequency be ω ₁ =(2-λ)ω _e =1.5ω _e , taking the current angle signal of the permanent magnet synchronous motor as 0.5ω _e single-frequency disturbance,

Among them, k _i /ω _r1 <<k _p , a _1.5 is the 1.5th order current amplitude, a ₁ is the 1st order current amplitude, a _0.5 is the 0.5th order current amplitude, and λ _k is the sinusoidal disturbance amplitude of the PMSM value, k _p is the ratio of the PI regulator.

In the above formula (9), J ₀ (λ _k ) = 1, J ₁ (λ _k ) = 0.01, ω _e = 250 Hz, λ = 0.5, k _p = 0.3, k _i = 60, and calculate 1.5 ω _e harmonic current content and 0.5ω _e harmonic current content, a _1.5 /a ₁ =0.33%, a _0.5 /a ₁ =0.81%. According to the harmonic current analysis block diagram constructed in Figure 3, the harmonic analysis results can be obtained, and the analysis results are shown in Figure 4. Therefore, the impact of the periodic error in the rotor position signal of the permanent magnet synchronous motor on the AC side current harmonics can be quantitatively analyzed through the above formula, that is, the periodic error in the working process of the permanent magnet synchronous motor can be quantitatively analyzed.

In the method for analyzing the periodic error of the permanent magnet synchronous motor in the embodiment of the present invention, through the periodic error analysis of the permanent magnet synchronous motor, it is beneficial to perform online compensation of the periodic error in time according to the known cause of the periodic error, and further Improve periodic error and improve online compensation accuracy.

Example 2

An embodiment of the present invention provides a device for analyzing the periodic error of a permanent magnet synchronous motor, as shown in FIG. 5 , including:

The determination module 51 is used to determine the current angle signal, the preset harmonic frequency and the preset fundamental frequency of the permanent magnet synchronous motor in a state of constant rotation speed.

The first calculation module 52 is configured to calculate the initial sine function corresponding to the current angle signal according to the current angle signal, the preset harmonic frequency and the preset fundamental frequency.

The second calculation module 53 is configured to calculate the complex vector function corresponding to the initial sine function during the coordinate transformation process of the current angle signal.

The target harmonic current generation module 54 is configured to generate the first target harmonic current frequency through the first coordinate transformation path and generate the second target harmonic current frequency through the second coordinate transformation path according to the complex vector function and the preset fundamental frequency .

The analysis and verification module 55 is configured to analyze and verify the permanent magnet synchronous motor through the preset periodic error analysis algorithm according to the preset fundamental frequency, the preset harmonic frequency, the first target harmonic current frequency and the second target harmonic current frequency Periodic error.

In the method for analyzing the periodic error of the permanent magnet synchronous motor in the embodiment of the present invention, in FIG. 5 , the determination module 51 includes:

The first determination sub-module 511 is used to determine the initial angle signal of the permanent magnet synchronous motor under various rotational speed states;

The second determination sub-module 512 is configured to determine, according to the initial angle signal, the current angle signal of the permanent magnet synchronous motor in a state of constant rotational speed.

In the device for analyzing the periodic error of the permanent magnet synchronous motor in the embodiment of the present invention, the determination module 51 determines the current angle signal of the permanent magnet synchronous motor in a constant rotational speed state according to the initial angle signal, through the above formulas (1) and (2). The calculation is not repeated here.

In the device for analyzing the periodic error of the permanent magnet synchronous motor in the embodiment of the present invention, the second calculation module 53 calculates the initial sine function corresponding to the current angle signal according to the current angle signal, the preset harmonic frequency and the preset fundamental frequency. Formula (3) is used for calculation, which is not repeated here.

In the analysis device for the periodic error of the permanent magnet synchronous motor in the embodiment of the present invention, the second calculation module 53, in the process of coordinate transformation of the current angle signal, calculates the complex vector function corresponding to the initial sine function through the above formula (4), ( 5), (6) are calculated, which will not be repeated here.

In the device for analyzing the periodic error of the permanent magnet synchronous motor in the embodiment of the present invention, the analysis and verification module analyzes the periodic error according to the preset fundamental frequency, the first target harmonic current frequency and the second target harmonic current frequency. The algorithm analysis verifies that the periodic error of the permanent magnet synchronous motor is calculated by the above equations (7) and (8), and will not be repeated here.

In the device for analyzing the periodic error of the permanent magnet synchronous motor in the embodiment of the present invention, through the periodic error analysis of the permanent magnet synchronous motor, it is beneficial to perform online compensation of the periodic error in time according to the known cause of the periodic error, and further Improve periodic error and improve online compensation accuracy.

Example 3

An embodiment of the present invention provides a permanent magnet synchronous motor control system, as shown in FIG. 6 , including:

The first axial current loop PI regulator 601 is used for receiving the first axial current signal, and performing PI adjustment control on the first axial current signal to output the first axial voltage signal. Here, the first axial current loop PI regulator 601 is a d-axis current loop PI regulator, which can receive a d-axis current command. In FIG. 6 , the d-axis current command is i ^* _d , and the d-axis current command passes through the first The axial current loop PI regulator 601 performs PI adjustment control and outputs a d-axis voltage command. In FIG. 6 , the d-axis voltage command is u ^* _d .

The second axial current loop PI regulator 602 is used for receiving the second axial current signal, and performing PI adjustment control on the second axial current signal to output the second axial voltage signal. The second axial current loop PI regulator 602 here is a q-axis current loop PI regulator, which can receive a q-axis current command. In FIG. 6, the q-axis current command is i ^* _q , and the q-axis current command is passed through the The two-axis current loop PI regulator 602 outputs a q-axis voltage command. In FIG. 6 , the d-axis voltage command is u ^* _q .

The first coordinate converter 603 is respectively connected with the first axial current loop PI regulator 601 and the second axial current loop PI regulator 602 . The first coordinate transformer 603 may be represented by an Ipark coordinate transformer.

The PWM modulator 604 is connected to the first coordinate converter 603 .

The inverter 605 is connected to the PWM modulator 604 . The inverter 605 is referred to as Inverter for short, and the input terminal voltage of the inverter 605 is U _dc .

The second coordinate converter 606 is connected to the first axial current loop PI regulator 601 , the second axial current loop PI regulator 602 and the first coordinate converter 603 respectively. The second coordinate transformer 606 may be represented by a Park transformer.

The current sensor 607 is connected to the second coordinate converter 606 and the inverter 605, respectively. The current sensor 607 is referred to as Sensor for short. In _FIG . 6 , the current sensor 607 outputs three-phase current signals, i _a , _ib , and ic , respectively.

The permanent magnet synchronous motor 608 is connected to the current sensor 607 . The permanent magnet synchronous motor 608 is referred to as PMSM for short.

The resolver 609 is connected to the permanent magnet synchronous motor 608 . The resolver 609 may be abbreviated as RDC. The resolver 609 is used to detect the position signal of the permanent magnet synchronous motor 608 , and in FIG. 6 , the angle output by the resolver 609 is θ.

The angle sine and cosine transformer 610 is respectively connected with the angle sine and cosine transformer 610, the first coordinate transformer 603 and the second coordinate transformer 606; referred to as sinθ/cosθ for short.

As shown in FIG. 7 , the permanent magnet synchronous motor control system further includes: a processor 611, connected to the permanent magnet synchronous motor 608, the processor includes a computer program stored on a computer-readable storage medium, and the computer program includes program instructions, when When the program instructions are executed by the computer, the computer is made to execute the steps of the periodic error analysis method of the permanent magnet synchronous motor in the first embodiment. In FIG. 7 , the permanent magnet synchronous motor control system includes one or more processors 611 and a memory 613 , and one processor 611 is taken as an example in FIG. 7 .

The server performing the processing method of list item operation may further include: an input device 614 and an output device 615 .

The processor 611 , the memory 613 , the input device 614 and the output device 615 may be connected by a bus or in other ways, and the connection by a bus is taken as an example in FIG. 6 .

The processor 611 may be a central processing unit (Central Processing Unit, CPU). The processor 611 may also be other general-purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuit (Application Specific Integrated Circuit, ASIC), Field-Programmable Gate Array (Field-Programmable Gate Array, FPGA) or Other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components and other chips, or a combination of the above types of chips.

Example 4

An embodiment of the present invention provides a computer-readable storage medium, on which computer instructions are stored, and when the instructions are executed by a processor, implement the steps of the method for analyzing periodic errors of a permanent magnet synchronous motor in Embodiment 1. The computer-readable storage medium also stores the current angle signal, the preset harmonic frequency, the preset fundamental frequency, the initial sine function, the complex vector function, the first target harmonic current frequency, the second target harmonic current frequency, Preset periodic error analysis algorithm, etc. Wherein, the computer-readable storage medium may be a magnetic disk, an optical disk, a read-only memory (Read-Only Memory, ROM), a random access memory (Random Access Memory, RAM), a flash memory (Flash Memory), a hard disk (Hard) DiskDrive, abbreviation: HDD) or solid-state drive (Solid-State Drive, SSD), etc.; the storage medium may also include a combination of the above-mentioned types of memories.

Those skilled in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and when the program is executed , which may include the processes of the above-mentioned method embodiments. The storage medium may be a magnetic disk, an optical disk, a read only memory (ROM), or a random access memory (RAM) or the like.

Obviously, the above-mentioned embodiments are only examples for clear description, and are not intended to limit the implementation manner. For those of ordinary skill in the art, changes or modifications in other different forms can also be made on the basis of the above description. There is no need and cannot be exhaustive of all implementations here. And the obvious changes or changes derived from this are still within the protection scope of the present invention.

Claims (10)

1. an analytical method for the periodic error of a permanent magnet synchronous motor, is characterized in that, comprises the steps: Determine the current angle signal, the preset harmonic frequency and the preset fundamental frequency of the permanent magnet synchronous motor at a constant speed; calculating an initial sine function corresponding to the current angle signal according to the current angle signal, the preset harmonic frequency and the preset fundamental frequency; During the coordinate transformation process of the current angle signal, the complex vector function corresponding to the initial sine function is calculated; generating a first target harmonic current frequency through a first coordinate transformation path and generating a second target harmonic current frequency through a second coordinate transformation path according to the complex vector function and the preset fundamental frequency; According to the preset fundamental frequency, the preset harmonic frequency, the first target harmonic current frequency and the second target harmonic current frequency, the period of the permanent magnet synchronous motor is analyzed and verified by a preset periodic error analysis algorithm sexual error. 2. The method for analyzing the periodic error of a permanent magnet synchronous motor according to claim 1, wherein the step of determining the current angle signal of the permanent magnet synchronous motor at a constant rotational speed state comprises: Determine the initial angle signal of the permanent magnet synchronous motor under various rotational speed states; According to the initial angle signal, the current angle signal of the permanent magnet synchronous motor in the state of constant rotational speed is determined. 3. the analysis method of the periodic error of permanent magnet synchronous motor according to claim 2, is characterized in that, described according to described initial angle signal, determine the current angle signal of permanent magnet synchronous motor under the state of constant rotational speed by following formula calculate:

θ _e =K·θ _rdc , K=n _p /p _rdc Among them, e _h is the harmonic in the initial angle signal, k is the harmonic frequency, a _k is the k-th harmonic amplitude and

is the k-th harmonic phase, θ _rdc is the initial angle signal, ω _rdc is the angular frequency; θ _e is the current angle signal, n _p is the number of pole pairs of the permanent magnet synchronous motor, p _rdc is the number of resolver pole pairs, and K is the permanent The ratio of the number of pole pairs to the number of resolver pole pairs for a magnetic synchronous motor. 4 . The method for analyzing the periodic error of a permanent magnet synchronous motor according to claim 1 , wherein the calculation is performed according to the current angle signal, the preset harmonic frequency and the preset fundamental frequency. 5 . The initial sine function corresponding to the current angle signal is calculated by the following formula:

in,

J _n (λ _k ) is the n-th order Bessel function of the first kind with a frequency modulation index of λ _k ,

θ _e is the current angle signal, ω _e is the preset fundamental frequency, λ is the preset harmonic frequency, and λ _k is the sinusoidal disturbance amplitude of the permanent magnet synchronous motor. 5. the analysis method of the periodic error of permanent magnet synchronous motor according to claim 1 is characterized in that, in the coordinate transformation process of described current angle signal, the formula of calculating the complex vector function corresponding to described initial sine function is as follows : J _-n (λ _k )=(-1) ⁿ J _n (λ _k )

sinθ _e =J ₀ (λ _k )sin(ω _e t)+J ₁ (λ _k )sin(ω _e t+λω _e t)+J ₋₁ (λ _k )sin(ω _e t-λω _e t) +...

Wherein, θ _e is the current angle signal, ω _e is the preset fundamental frequency, λ is the preset harmonic frequency, λ _k is the sinusoidal disturbance amplitude of the permanent magnet synchronous motor,

is the complex vector function. 6 . The method for analyzing the periodic error of a permanent magnet synchronous motor according to claim 1 , wherein, according to the preset fundamental frequency, the preset harmonic frequency, the first target harmonic current frequency and the According to the second target harmonic current frequency, the periodic error of the permanent magnet synchronous motor is analyzed and verified by the preset periodic error analysis algorithm, and the periodic error is calculated by the following formula: Let the preset fundamental frequency be ω _e , let the preset harmonic frequency λ be 0.5, let the first target harmonic current frequency be ω ₂ =λω _e =0.5ω _e , let the second target harmonic current frequency be ω ₁ =(2-λ)ω _e =1.5ω _e , and the current angle signal of the permanent magnet synchronous motor is a single-frequency disturbance of 0.5ω _e ,

Among them, a _1.5 is the 1.5th order current amplitude, a ₁ is the 1st order current amplitude, a _0.5 is the 0.5th order current amplitude, _{k p} is the ratio of the PI regulator, ki is the integral coefficient of the PI regulator, Z _a is the equivalent impedance of phase A, K _PI is the equivalent gain of the PI regulator,

is the phase of the corresponding frequency component,

is the first phase angle difference between the PI regulator and the impedance corresponding to the first frequency component,

is the second phase angle difference between the PI regulator and the impedance corresponding to the second frequency component,

is the third phase angle difference between the PI regulator and the impedance corresponding to the first frequency component,

is the fourth phase angle difference between the PI regulator and the impedance corresponding to the first frequency component,

ω _r1 is the frequency of the input signal corresponding to the PI regulator, ω _r2 is the frequency of the input signal corresponding to the load, and U _s is the phase voltage amplitude of the dq coordinate system. When the current response enters a steady state, the DC input component of the PI regulator is zero. , the 0.5ω _e frequency current harmonics are rotated by the u _dq DC component via the rotation vector

produce. 7. The method for analyzing the periodic error of a permanent magnet synchronous motor according to claim 1, wherein the method is based on a preset fundamental frequency, a preset harmonic frequency, the first target harmonic current frequency and the The second target harmonic current frequency is analyzed and verified by the preset periodic error analysis algorithm, and the periodic error of the permanent magnet synchronous motor is also calculated by the following formula: Let the preset fundamental frequency be ω _e , let the preset harmonic frequency λ be 0.5, let the first target harmonic current frequency be ω ₂ =λω _e =0.5ω _e , let the second target harmonic current frequency be ω ₁ =(2-λ)ω _e =1.5ω _e , and the current angle signal of the permanent magnet synchronous motor is a single-frequency disturbance of 0.5ω _e ,

Wherein, k _i /ω _r1 <<k _p , a _1.5 is the 1.5th order current amplitude, a ₁ is the 1st order current amplitude, a _0.5 is the 0.5th order current amplitude, λ _k is the sine of the permanent magnet synchronous motor The perturbation amplitude, k _p is the ratio of the PI regulator. 8. An analysis device for the periodic error of a permanent magnet synchronous motor, characterized in that, comprising: A determination module, used to determine the current angle signal, the preset harmonic frequency and the preset fundamental frequency of the permanent magnet synchronous motor in a state of constant speed; a first calculation module, configured to calculate the initial sine function corresponding to the current angle signal according to the current angle signal, the preset harmonic frequency and the preset fundamental frequency; a second calculation module, configured to calculate the complex vector function corresponding to the initial sine function during the coordinate transformation process of the current angle signal; A target harmonic current generation module is configured to generate a first target harmonic current frequency through a first coordinate transformation path and a second target harmonic current through a second coordinate transformation path according to the complex vector function and the preset fundamental frequency. wave current frequency; An analysis and verification module for analyzing the preset periodic error analysis algorithm according to the preset fundamental frequency, preset harmonic frequency, the first target harmonic current frequency and the second target harmonic current frequency Verify the periodic error of a permanent magnet synchronous motor. 9. A permanent magnet synchronous motor control system, characterized in that, comprising: The first axial current loop PI regulator is used for receiving the first axial current signal, and performing PI adjustment and control on the first axial current signal to output the first axial voltage signal; The second axial current loop PI regulator is used for receiving the second axial current signal, and performing PI adjustment and control on the second axial current signal to output the second axial voltage signal; a first coordinate converter, respectively connected to the first axial current loop PI regulator and the second axial current loop PI regulator; a PWM modulator, connected to the first coordinate converter; an inverter, connected with the PWM modulator; a second coordinate converter, respectively connected to the first axial current loop PI regulator, the second axial current loop PI regulator and the first coordinate converter; a current sensor, connected to the second coordinate converter and the inverter respectively; a permanent magnet synchronous motor, connected with the current sensor; a rotary transformer, connected with the permanent magnet synchronous motor; an angle sine-cosine converter, connected with the resolver; a processor connected to the permanent magnet synchronous motor, the processor including a computer program stored on a computer-readable storage medium, the computer program including program instructions, when the program instructions are executed by a computer, cause the computer to execute The steps of the method for analyzing the periodic error of a permanent magnet synchronous motor according to any one of claims 1-7. 10. A computer device, comprising: a memory and a processor, wherein the memory and the processor are connected in communication with each other, and computer instructions are stored in the memory, wherein the processor executes the computer by executing the instruction, so that the computer executes the steps of the method for analyzing the periodic error of the permanent magnet synchronous motor according to any one of claims 1-7.

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