阅读说明：本技术 带有谐波抑制的永磁同步电机无速度传感器控制方法 (Permanent magnet synchronous motor speed sensorless control method with harmonic suppression ) 是由 吴秋轩 王彩彬 林伟杰 迟晓妮 王坚 张波涛 严文生 于 2021-07-02 设计创作，主要内容包括：本发明涉及一种带有谐波抑制的永磁同步电机无速度传感器控制方法,属于电机控制技术领域。该方法通过模型参考自适应模型估算电机的位置和速度,替换传统的永磁同步电机的机械式位置传感器,降低运行成本,提高了系统的可靠性；同时本发明针对电机运行时出现的电流谐波,设计了抑制谐波的方法：基于滑模观测器估计电磁转矩脉动,计算补偿电流,加入低通滤波器得到平均转矩,进而得到转矩脉动。(The invention relates to a permanent magnet synchronous motor speed sensorless control method with harmonic suppression, and belongs to the technical field of motor control. The method estimates the position and the speed of the motor by referring to the self-adaptive model through the model, replaces a mechanical position sensor of the traditional permanent magnet synchronous motor, reduces the operation cost and improves the reliability of the system; meanwhile, aiming at the current harmonic wave generated when the motor operates, the invention designs a method for inhibiting the harmonic wave, which comprises the following steps: and estimating the electromagnetic torque ripple based on the sliding mode observer, calculating a compensation current, adding a low-pass filter to obtain an average torque, and further obtaining the torque ripple.)

1. A permanent magnet synchronous motor speed sensorless control method with harmonic suppression is characterized by comprising the following steps:

carrying out rotating speed and current double closed-loop control on the permanent magnet synchronous motor according to the given rotating speed of the permanent magnet synchronous motor, the d-axis current given value, the current rotating speed, the d-axis current sampling value and the q-axis current sampling value; according to the alpha-axis reference voltage u_αReference current i_αAnd a beta-axis reference voltage u_βReference current i_βEstimating electromagnetic torque ripple by a sliding mode observer, and calculating compensation currentFor the permanent magnet synchronous motorCurrent harmonic suppression is performed.

2. The method for controlling the PMSM speed sensorless with harmonic suppression according to claim 1, wherein the PMSM speed current double closed loop control is performed according to the given speed, the d-axis current given value, the current speed, the d-axis current sample value and the q-axis current sample value of the PMSM, specifically comprising:

the difference value of the given rotating speed and the current rotating speed of the permanent magnet synchronous motor is regulated by a PI regulator to obtain q-axis reference current, the difference value of the q-axis reference current and the q-axis current sampling value is regulated by a PI regulator to obtain q-axis reference voltage, the difference value of the d-axis current given value and the d-axis current sampling value is regulated by a PI regulator to obtain d-axis reference voltage, the q-axis reference voltage and the d-axis reference voltage are converted into a two-phase static coordinate system according to the current rotor position to generate alpha-axis reference voltage and beta-axis reference voltage, the alpha-axis reference voltage and the beta-axis reference voltage are subjected to SVPWM modulation to output PWM control waves to an inverter circuit, a, b and c currents are output to control the permanent magnet synchronous motor, and three-phase currents of the permanent magnet synchronous motor are subjected to coordinate conversion, and obtaining a d-axis current sampling value and a q-axis current sampling value, carrying out current closed loop, establishing a model reference self-adaptive module to estimate the rotating speed and the position according to the d-axis current sampling value, the q-axis reference voltage and the d-axis reference voltage, and carrying out rotating speed closed loop control.

3. The method for controlling the non-speed sensor of the permanent magnet synchronous motor with the harmonic suppression function according to claim 2, wherein d-axis current sampling values and q-axis current sampling values are obtained through coordinate transformation according to three-phase currents of the permanent magnet synchronous motor, and the method specifically comprises the following steps:

obtaining three-phase current of the permanent magnet synchronous motor, obtaining dq axis current according to coordinate transformation,

wherein i_dD-axis current, i, for stator winding_qQ-axis current, i, for stator winding_a、i_b、i_cIs a three-phase current of a permanent magnet synchronous motor i_αFor alpha-axis reference current, i_βIs a reference current of beta axis, theta_eIs the included angle between the dq coordinate system and the a axis of the three-phase static coordinate system.

4. The method of claim 2, wherein the stator current equation of the PMSM in the synchronous rotating coordinate system is established, and in the PMSM, the d-axis inductance L_dAnd q-axis inductance L_qAre equal to obtain L_d＝L_q＝L_s(ii) a According to L_d＝L_q＝L_sThe method for establishing the stator current equation of the permanent magnet synchronous motor in the synchronous rotation coordinate system specifically comprises the following steps:

wherein u is_dIs the d-axis voltage, u, of the stator winding_qIs the q-axis voltage, i, of the stator winding_dD-axis current, i, for stator winding_qQ-axis current, psi, of stator winding_fIs stator flux linkage, L_sIs stator winding inductance, R_sIs stator winding resistance, w_eIs the rotor electrical angular speed.

5. The method for controlling the permanent magnet synchronous motor without the speed sensor with the harmonic suppression function according to claim 2, wherein the establishing of the reference model and the adjustable model according to the stator current equation specifically comprises:

order toi_q ^*＝i_q，u_q ^*＝u_q

The reference motor model can be written as:

the parallel adjustable model is:

wherein the content of the first and second substances,is i_d ^*Is determined by the estimated value of (c),is i_q ^*Is determined by the estimated value of (c),is u_d ^*Is determined by the estimated value of (c),is u_q ^*Is determined by the estimated value of (c),is w_eAn estimate of (d).

6. The method for controlling the PMSM speed sensorless with harmonic suppression according to claim 5, wherein obtaining a speed estimation model and a position estimation model according to the reference model and the adjustable model specifically comprises:

the MRAS reference model and the adjustable model are respectively abbreviated as the following forms:

reference model: pi (total internal diameter)^*＝Ai^*+Bu^*

The adjustable model is as follows:

wherein p is a differential operator defining a generalized errorObtaining an error equation:

in the formula (I), the compound is shown in the specification,

7. the method of claim 6, wherein the current speed of the PMSM is estimated using the speed estimation model; estimating the current rotor position of the permanent magnet synchronous motor by using the position estimation model, specifically comprising:

according to the Popov hyperstable theory, a rotating speed identification formula is as follows:

wherein k is_iIs the integral coefficient, k, of the PI regulator_pThe proportional coefficient of the PI regulator;

obtaining the position estimation model and the estimated position angle of the rotor according to the speed estimation modelComprises the following steps:

8. the method of claim 1, wherein the current rotor position of the PMSM is estimated using the position estimation model; according to the alpha-axis reference voltage u_αReference current i_αAnd a beta-axis reference voltage u_βReference current i_βEstimating electromagnetic torque ripple by a sliding mode observer, and calculating compensation currentThe current harmonic suppression is carried out on the permanent magnet synchronous motor, and the method specifically comprises the following steps:

the sliding-mode observer observes the counter electromotive force, and the current state equation form of the motor is as follows:

wherein:w_efor the electrical angular velocity of the rotorDegree, E_α、E_βIs a back electromotive force;

the design equation form of the traditional sliding-mode observer is as follows:

wherein the content of the first and second substances,as an observed value of the stator current,is a control input of the observer;

the current equation of the motor is subtracted from the design equation of the traditional sliding-mode observer, and the error equation of the stator current is as follows:

wherein the content of the first and second substances,current observation error;

the sliding mode control law is designed as follows:

wherein the content of the first and second substances,

according to back electromotive force v_α、v_βAnd the motor rotating speed n, obtaining an estimated electromagnetic torque:

electromagnetic torque T_eObtaining the desired torque through a low-pass filterElectromagnetic torque T_eWith desired torqueObtaining torque ripple delta T by difference_eEquation of the meridianObtaining a compensation current

And according to the q-axis reference current and the compensation current, subtracting the q-axis reference current and the compensation current to obtain the q-axis reference current with reduced harmonic, and performing current harmonic suppression.

Technical Field

The invention relates to the field of permanent magnet synchronous motor control, in particular to a permanent magnet synchronous motor speed sensorless control method with harmonic suppression

Background

In order to obtain accurate rotor position and rotation speed information in real time, a conventional method is to install a mechanical sensor on a rotor shaft, wherein the mechanical sensor comprises a photoelectric encoder, a hall sensor and the like. However, this will lead to a number of problems, such as increased cost, volume and inertia, and reduced reliability and robustness. Based on the above disadvantages, the research of velocity-free sensor vector control is gradually paid high attention to the academic and engineering circles at home and abroad. MRAS is an efficient speed identification control system, mainly based on the self-adaptive theory. The system comprises two models: the system comprises a reference model and an adjustable model, wherein the former does not contain unknown parameters, the latter contains unknown parameters, the two models have common output under common input, the output and state performance indexes of the reference model and the adjustable model obtain an error equation through a feedback comparator, and a proper self-adaptive law is constructed, so that a control object of the adjustable model can follow the dynamic response of the reference model, and the control error tends to zero. Due to the non-linearity of the inverter in the control system and the non-sinusoidal waveform of the back electromotive force of the motor, low-frequency subharmonics appear in the winding current, which causes the torque fluctuation and loss increase of the motor, and the control performance of the system is deteriorated.

Disclosure of Invention

The invention aims to solve the problem of large speed fluctuation caused by overlarge torque pulsation when a high-speed permanent magnet synchronous motor estimates the speed, and provides a permanent magnet synchronous motor speed sensorless control method with harmonic suppression.

The technical scheme of the invention is as follows:

according to permanent magnet synchronizationThe given rotating speed of the motor, the given value of d-axis current, the current rotating speed, the d-axis current sampling value and the q-axis current sampling value are used for carrying out rotating speed and current double closed-loop control on the permanent magnet synchronous motor; according to the alpha-axis reference voltage u_αReference current i_αAnd a beta-axis reference voltage u_βReference current i_βEstimating electromagnetic torque ripple by sliding-mode observer, and calculating compensation currentAnd carrying out current harmonic suppression on the permanent magnet synchronous motor.

According to the given rotating speed of the permanent magnet synchronous motor, a d-axis current given value, the current rotating speed, a d-axis current sampling value and a q-axis current sampling value, the permanent magnet synchronous motor is subjected to rotating speed and current double closed-loop control, and the method specifically comprises the following steps:

the difference value between the given rotating speed and the current rotating speed of the permanent magnet synchronous motor is regulated by a PI regulator to obtain q-axis reference current, the difference value between the q-axis reference current and the q-axis current sampling value is regulated by the PI regulator to obtain q-axis reference voltage, the difference value between the d-axis current given value and the d-axis current sampling value is regulated by the PI regulator to obtain d-axis reference voltage, and the q-axis reference voltage and the d-axis reference voltage are converted into a two-phase static coordinate system according to the current rotor position to generate alpha-axis reference voltage and beta-axis reference voltage; carrying out SVPWM (space vector pulse width modulation) on the alpha-axis reference voltage and the beta-axis reference voltage, outputting PWM signals to an inverter circuit, outputting a, b and c three-phase currents to control a permanent magnet synchronous motor, carrying out coordinate transformation on the three-phase currents of the permanent magnet synchronous motor to obtain a d-axis current sampling value and a q-axis current sampling value, carrying out current closed loop, establishing a model reference self-adaptive module to estimate the rotating speed and the position according to the d-axis current sampling value, the q-axis reference voltage and the d-axis reference voltage, and carrying out rotating speed closed loop;

according to the three-phase current of the permanent magnet synchronous motor, a d-axis current sampling value and a q-axis current sampling value are obtained through coordinate transformation, current closed loop is carried out, and a coordinate transformation formula specifically comprises the following steps:

wherein i_dD-axis current, i, for stator winding_qQ-axis current, i, for stator winding_a、i_b、i_cIs a three-phase current of a permanent magnet synchronous motor i_αFor alpha-axis reference current, i_βIs a reference current of beta axis, theta_eIs d_qThe included angle between the coordinate system and the axis a of the three-phase static coordinate system;

the establishing of the stator current equation of the permanent magnet synchronous motor under the synchronous rotation coordinate system specifically comprises the following steps: in a permanent magnet synchronous machine, d-axis inductance L_dAnd q-axis inductance L_qAre equal to obtain L_d＝L_q＝L_s(ii) a According to L_d＝L_q＝L_sEstablishing a stator current equation of the permanent magnet synchronous motor under a synchronous rotation coordinate system as follows:

wherein u is_dIs the d-axis voltage, u, of the stator winding_qIs the q-axis voltage, i, of the stator winding_dD-axis current, i, for stator winding_qQ-axis current, psi, of stator winding_fIs stator flux linkage, L_sIs stator winding inductance, R_sIs stator winding resistance, w_eIs the rotor electrical angular speed;

establishing a reference model and an adjustable model according to the stator current equation, which specifically comprises the following steps:

order toi_q ^*＝i_q，u_q ^*＝u_q

The reference motor model can be written as:

the parallel adjustable model is:

wherein the content of the first and second substances,is i_d ^*Is determined by the estimated value of (c),is i_q ^*Is determined by the estimated value of (c),is u_d ^*Is determined by the estimated value of (c),is u_q ^*Is determined by the estimated value of (c),is w_eAn estimated value of (d);

obtaining a speed estimation model and a position estimation model according to the reference model and the adjustable model, and specifically comprising:

the MRAS reference model and the adjustable model are respectively abbreviated as the following forms:

reference model: pi (total internal diameter)^*＝Ai^*+Bu^*

The adjustable model is as follows:

defining generalized errorObtaining an error equation:

in the formula (I), the compound is shown in the specification,according to a Popov ultra-stable theory, obtaining a rotating speed identification formula:

wherein k is_iIs the integral coefficient, k, of the PI regulator_pThe proportional coefficient of the PI regulator;

obtaining the position estimation model and the estimated position angle of the rotor according to the speed estimation modelComprises the following steps:

according to the alpha-axis reference voltage u_αReference current i_αAnd a beta-axis reference voltage u_βReference current i_βEstimating electromagnetic torque ripple by a sliding mode observer, and calculating compensation currentAnd carrying out current harmonic suppression on the permanent magnet synchronous motor. The method specifically comprises the following steps:

the sliding-mode observer observes the counter electromotive force, and the current state equation form of the motor is as follows:

wherein:w_eas electrical angular speed of the rotor, E_α、E_βIs a back electromotive force;

the design equation form of the traditional sliding-mode observer is as follows:

wherein the content of the first and second substances,as an observed value of the stator current,is a control input of the observer;

the current equation of the motor is subtracted from the design equation of the traditional sliding-mode observer, and the error equation of the stator current is as follows:

wherein the content of the first and second substances,current observation error;

the sliding mode control law is designed as follows:

wherein the content of the first and second substances,

according to back electromotive force v_α、v_βAnd the motor rotating speed n, obtaining an estimated electromagnetic torque:

electromagnetic torque T_eObtaining the desired torque through a low-pass filterElectromagnetic torque T_eWith desired torqueThe difference is made to obtain the torque ripple delta T_eEquation of the meridianObtaining a compensation current

And according to the q-axis reference current and the compensation current, subtracting the q-axis reference current and the compensation current to obtain the q-axis reference current with reduced harmonic, and performing current closed-loop control.

The substantial effects of the invention are as follows: the method for controlling the permanent magnet synchronous motor without the speed sensor with the harmonic suppression is provided, so that the problem of large speed fluctuation caused by overlarge torque pulsation when the high-speed permanent magnet synchronous motor estimates the speed is solved.

Drawings

FIG. 1 is a schematic flow chart of a method for controlling a permanent magnet synchronous motor without a speed sensor with harmonic suppression according to the present invention;

FIG. 2 is a schematic diagram of a dual closed-loop control of the rotating speed and current of the permanent magnet synchronous motor provided by the present invention;

FIG. 3 is a schematic diagram of harmonic suppression of a PMSM according to the present invention;

fig. 4 is a speed sensorless control schematic diagram of a permanent magnet synchronous motor with harmonic suppression according to the present invention.

Detailed Description

The invention provides a permanent magnet synchronous motor speed sensorless control method with harmonic suppression, which comprises the following steps as shown in figure 1:

step 1: the method for controlling the permanent magnet synchronous motor in a double closed loop mode based on the MRAS comprises the following steps as shown in figures 2 and 4:

(1) the difference value between the given rotating speed and the current rotating speed of the permanent magnet synchronous motor is regulated by a PI regulator to obtain q-axis reference current; the difference value of the q-axis reference current and the q-axis current sampling value is regulated by a PI regulator to obtain q-axis reference voltage; the difference value between the d-axis current set value and the d-axis current sampling value is regulated by a PI regulator to obtain a d-axis reference voltage; converting the q-axis reference voltage and the d-axis reference voltage into a two-phase static coordinate system according to the current rotor position to generate an alpha-axis reference voltage and a beta-axis reference voltage; carrying out SVPWM (space vector pulse width modulation) on the alpha-axis reference voltage and the beta-axis reference voltage, outputting PWM control waves to an inverter circuit, and outputting a three-phase current of a, b and c to control the permanent magnet synchronous motor;

(2) according to the three-phase current of the permanent magnet synchronous motor, obtaining a d-axis current sampling value and a q-axis current sampling value through coordinate transformation, and carrying out current closed loop by using a coordinate transformation formula:

wherein i_dD-axis current, i, for stator winding_qQ-axis current, i, for stator winding_a、i_b、i_cIs a three-phase current of a permanent magnet synchronous motor i_αFor alpha-axis reference current, i_βIs a reference current of beta axis, theta_eIs d_qThe coordinate system and the axis a of the three-phase static coordinate system form an included angle.

(3) The establishing of the stator current equation of the permanent magnet synchronous motor under the synchronous rotation coordinate system specifically comprises the following steps: in a permanent magnet synchronous machine, d-axis inductance L_dAnd q-axis inductance L_qAre equal to obtain L_d＝L_q＝L_s(ii) a According to L_d＝L_q＝L_sEstablishing a stator current equation of the permanent magnet synchronous motor under a synchronous rotation coordinate system as follows:

wherein u is_dIs the d-axis voltage, u, of the stator winding_qIs the q-axis voltage, i, of the stator winding_dD-axis current, i, for stator winding_qQ-axis current, psi, of stator winding_fIs stator flux linkage, L_sIs stator winding inductance, R_sIs stator winding resistance, w_eIs the rotor electrical angular speed.

(4) Establishing a reference model and an adjustable model according to the stator current equation, which specifically comprises the following steps:

order toi_q ^*＝i_q，u_q ^*＝u_q

The reference motor model can be written as:

the parallel adjustable model is:

wherein the content of the first and second substances,is i_d ^*Is determined by the estimated value of (c),is i_q ^*Is determined by the estimated value of (c),is u_d ^*Is determined by the estimated value of (c),is u_q ^*Is determined by the estimated value of (c),is w_eAn estimate of (d).

(5) Obtaining a speed estimation model and a position estimation model according to the reference model and the adjustable model, and specifically comprising:

the MRAS reference model and the adjustable model are respectively abbreviated as the following forms:

reference model: pi (total internal diameter)^*＝Ai^*+Bu^*

The adjustable model is as follows:

wherein p is a differential operator defining a generalized errorObtaining an error equation:

in the formula (I), the compound is shown in the specification,according to a Popov ultra-stable theory, obtaining a rotating speed identification formula:

wherein k is_pIs the proportionality coefficient, k, of a PI regulator_iIs the integral coefficient of the PI regulator;

obtaining the position estimation model and the estimated position angle of the rotor according to the speed estimation modelComprises the following steps:

step 2: establishing a sliding mode observer to estimate electromagnetic torque ripple and calculating a compensation current according to the alpha-axis reference voltage u as shown in FIG. 3_αReference current i_αAnd a beta-axis reference voltage u_βReference current i_βEstimating electromagnetic torque ripple by a sliding mode observer, and calculating compensation currentAnd carrying out current harmonic suppression on the permanent magnet synchronous motor.

The method specifically comprises the following steps:

the sliding-mode observer observes the counter electromotive force, and the current state equation form of the motor is as follows:

wherein:w_eas electrical angular speed of the rotor, E_α、E_βIs a back electromotive force;

the design equation form of the traditional sliding-mode observer is as follows:

wherein the content of the first and second substances,as an observed value of the stator current,is a control input of the observer;

the current equation of the motor is subtracted from the design equation of the traditional sliding-mode observer, and the error equation of the stator current is as follows:

wherein the content of the first and second substances,current observation error;

the sliding mode control law is designed as follows:

wherein the content of the first and second substances,

according to back electromotive force v_α、v_βAnd the motor rotating speed n, obtaining an estimated electromagnetic torque:

electromagnetic torque T_eObtaining the desired torque through a low-pass filterElectromagnetic torque T_eWith desired torqueThe difference is made to obtain the torque ripple delta T_eEquation of the meridianObtaining a compensation current

And step 3: and carrying out harmonic suppression on the permanent magnet synchronous motor, and carrying out difference on the q-axis reference current and the compensation current to obtain the q-axis reference current with reduced harmonic so as to carry out current harmonic suppression.