CN117792178A

CN117792178A - Motor control method, apparatus and computer readable storage medium

Info

Publication number: CN117792178A
Application number: CN202311769709.3A
Authority: CN
Inventors: 王绍伟; 徐浩; 胡敬伟; 胡慧军; 艾程柳; 张巍
Original assignee: Anhui Meizhi Compressor Co Ltd
Current assignee: Anhui Meizhi Compressor Co Ltd
Priority date: 2023-12-20
Filing date: 2023-12-20
Publication date: 2024-03-29

Abstract

The application discloses a motor control method, a motor control device and a computer readable storage medium, wherein the motor control method comprises the following steps: determining a q-axis load disturbance compensation current according to the actual rotating speed of the motor and the q-axis actual current; compensating a q-axis given current according to the q-axis load disturbance compensation current, and determining a q-axis current error between the compensated q-axis given current and the q-axis actual current; determining a q-axis given voltage from the q-axis current error; and controlling an inverter to output a driving signal of the motor according to the q-axis given voltage and the d-axis given voltage. By suppressing the current harmonic wave of the motor, the motor loss and motor rotation speed fluctuation are reduced, and the stability of a motor control system is improved.

Description

Motor control method, apparatus and computer readable storage medium

Technical Field

The present disclosure relates to the field of motor control technologies, and in particular, to a motor control method, a motor control device, and a computer readable storage medium.

Background

The motor has the advantages of high efficiency, high torque density, high response speed and the like, and is widely applied to high-performance servo driving occasions such as wind power generation, electric automobiles, numerical control machine tools and the like. The motor control system adopts three closed-loop control, the inner ring is a current ring, the middle ring is a speed ring, and the outer ring is a position ring. The current loop is used as the innermost loop of the control system and is a key link for realizing high-precision control of the servo system.

The motor is influenced by non-ideal factors of the body and non-linear factors of the inverter, a large number of harmonic waves exist in the motor current, and meanwhile, in actual operation of the motor, load disturbance also influences the current harmonic wave content. These harmonics can cause excessive losses and large rotational speed fluctuations in the motor.

In the related art, the current can be quickly and accurately tracked by a predictive current control method, but predictive control depends on an accurate mathematical model of the system. When the model is inaccurate or the parameters are not matched, the motor control system can generate disturbance to reduce the current tracking precision and the harmonic suppression effect, and further the stability of the motor control system is reduced.

Disclosure of Invention

The embodiment of the application aims to inhibit current harmonic waves of a motor, reduce motor loss and motor rotation speed fluctuation and improve the stability of a motor control system by providing a motor control method, a motor control device and a computer readable storage medium.

The embodiment of the application provides a motor control method, which is used for a motor control system and comprises the following steps:

determining a q-axis load disturbance compensation current according to the actual rotating speed of the motor and the q-axis actual current;

Compensating a q-axis given current according to the q-axis load disturbance compensation current, and determining a q-axis current error between the compensated q-axis given current and the q-axis actual current;

determining a q-axis given voltage from the q-axis current error;

and controlling an inverter to output a driving signal of the motor according to the q-axis given voltage and the d-axis given voltage.

Optionally, the motor control system includes: the step of determining q-axis load disturbance compensation current according to the actual rotating speed of the motor and the q-axis actual current comprises the following steps of:

inputting the actual rotating speed and q-axis actual current of the motor into the load disturbance sliding mode observer to obtain a load torque observation value;

and inputting the load torque observation value into the gain operator module for calculation to obtain the q-axis load disturbance compensation current.

Optionally, the step of inputting the actual rotation speed and q-axis actual current of the motor into the load disturbance sliding mode observer to obtain a load torque observed value includes:

inputting the actual rotating speed and q-axis actual current of the motor into a load disturbance sliding mode observer, and calculating based on a sliding mode control function in the load disturbance sliding mode observer to obtain the load torque observation value, wherein the load disturbance sliding mode observer is expressed as:

Wherein T is _s Represents the control period, K _e Represents a torque coefficient, J is moment of inertia, i _q Represents the q-axis actual current, B is the resistance friction coefficient, k is the sliding mode coefficient,for the observed value of the actual rotational speed, +.>Representing load torque T _L Load torque observations of V _smf Representing a sliding mode control function, the sliding mode control function being represented as:

where λ represents the approach law parameter and s is the slip plane.

Optionally, the step of inputting the observed load torque value into the gain operator module for calculation to obtain the q-axis load disturbance compensation current includes:

inputting the load torque observation value into the gain operator module, and calculating to obtain the q-axis load disturbance compensation current based on a gain operator in the gain operator module, wherein the gain operator is expressed as:

wherein K is _e As a coefficient of torque,is a load torque observation.

Optionally, the motor control system further comprises: the speed loop controller compensates a q-axis given current according to the q-axis load disturbance compensation current, and further includes, before the step of determining a q-axis current error between the compensated q-axis given current and the q-axis actual current:

acquiring a given speed of the motor;

Determining a speed difference based on the given speed and an actual speed of the motor;

and inputting the speed difference value into the speed loop controller to obtain the q-axis given current.

Optionally, the motor control system further comprises: the q-axis proportional resonance controller, the step of determining a q-axis given voltage from the q-axis current error includes:

inputting the q-axis current error into the q-axis proportional resonance controller, and calculating to obtain the q-axis given voltage according to the q-axis current error and a transfer function, wherein a calculation formula corresponding to the q-axis given voltage is expressed as:

wherein e _q For q-axis current error, G _PR (s) is a transfer function.

Optionally, the motor control system further comprises: the d-axis proportional resonance controller, before the step of controlling the inverter to output the driving signal of the motor according to the q-axis given voltage and the d-axis given voltage, further comprises:

acquiring d-axis given current and d-axis actual current;

determining a d-axis current error according to the d-axis given current and the d-axis actual current;

inputting the d-axis current error into the d-axis proportional resonance controller, and calculating to obtain the d-axis given voltage according to the d-axis current error and a transfer function, wherein a calculation formula corresponding to the d-axis given voltage is expressed as:

Wherein e _d For q-axis current error, G _PR (s) is a transfer function.

Optionally, the transfer function is expressed as:

wherein k is _pr Is a proportionality coefficient, k _ir Is the resonance coefficient omega _c Is bandwidth omega _n Is the resonant frequency.

Optionally, the motor control system further comprises: the step of controlling an inverter to output a driving signal of the motor according to the q-axis given voltage and the d-axis given voltage includes:

inputting the d-axis given voltage and the q-axis given voltage into an IPARK conversion module to obtain alpha-axis given voltage and beta-axis given voltage under a two-phase coordinate system;

inputting the alpha-axis given voltage and the beta-axis given voltage into an SVPWM module to obtain a space vector voltage signal;

and inputting the space vector voltage signal into an inverter to obtain a driving signal of the motor.

Optionally, the motor control system further comprises: the step of determining the q-axis load disturbance compensation current according to the actual rotating speed of the motor and the q-axis actual current further comprises the following steps:

acquiring three-phase alternating current of an inverter under a three-phase coordinate system;

inputting the three-phase alternating current into a CLARK conversion module to obtain alpha-axis current and beta-axis current under a two-phase coordinate system;

And passing the alpha-axis current and the beta-axis current through a PARK transformation module to obtain d-axis actual current and q-axis actual current under a rotating d-q coordinate system.

In addition, to achieve the above object, the present application also provides a motor control device including:

the load disturbance compensation current determining module is used for determining q-axis load disturbance compensation current according to the actual rotating speed of the motor and the q-axis actual current;

the q-axis current error determining module is used for compensating a q-axis given current according to the q-axis load disturbance compensation current and determining a q-axis current error between the q-axis given current after compensation and the q-axis actual current;

a q-axis given voltage determination module for determining a q-axis given voltage from the q-axis current error;

and the driving signal determining module is used for controlling the inverter to output the driving signal of the motor according to the q-axis given voltage and the d-axis given voltage.

In addition, in order to achieve the above object, the present application further provides a computer-readable storage medium having stored thereon a motor control program which, when executed by a processor, implements the steps of the motor control method described above.

According to the technical scheme of the motor control method, the motor control device and the computer readable storage medium, the q-axis load disturbance compensation current is determined according to the actual rotating speed and the q-axis actual current of the motor, and the q-axis given current is compensated through the q-axis load disturbance compensation current, so that errors between the q-axis actual current and the q-axis given current are reduced, the influence of load disturbance on the harmonic content of the motor current can be reduced, and finally the obtained driving signal of the motor is more accurate.

Drawings

FIG. 1 is a schematic diagram of a motor control system according to the present disclosure;

FIG. 2 is a schematic flow chart of a first embodiment of a motor control method according to the present application;

FIG. 3 is a schematic flow chart of a second embodiment of a motor control method according to the present application;

FIG. 4 is a schematic flow chart of a third embodiment of a motor control method according to the present application;

FIG. 5 is a flow chart of a fourth embodiment of a motor control method according to the present application;

FIG. 6 is a schematic flow chart of a fifth embodiment of a motor control method according to the present application;

FIG. 7 is a schematic flow chart of a sixth embodiment of a motor control method according to the present application;

fig. 8 is a functional block diagram of the motor control device of the present application.

The achievement of the objects, functional features and advantages of the present application will be further described with reference to embodiments, with reference to the accompanying drawings, which are only illustrations of one embodiment, but not all of the inventions.

Detailed Description

In order to better understand the above technical solution, exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

Aiming at the problems, the application provides a motor control method, which mainly comprises the following steps: determining a q-axis load disturbance compensation current according to the actual rotating speed of the motor and the q-axis actual current; compensating a q-axis given current according to the q-axis load disturbance compensation current, and determining a q-axis current error between the compensated q-axis given current and the q-axis actual current; determining a q-axis given voltage from the q-axis current error; and controlling an inverter to output a driving signal of the motor according to the q-axis given voltage and the d-axis given voltage. According to the actual rotating speed of the motor and the q-axis actual current, the q-axis load disturbance compensation current is determined, and the q-axis given current is compensated by the q-axis load disturbance compensation current, so that the error between the q-axis actual current and the q-axis given current is reduced, the influence of load disturbance on the current harmonic content of the motor can be reduced, and the finally obtained driving signal of the motor is more accurate.

In addition, the current loop controller adopts a proportional resonance controller, and the resonant frequency of the proportional resonance controller is adjusted to inhibit current harmonic waves of the motor.

The motor control system of the present application will be described in detail below.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a motor control system according to the present application, where suppression of harmonic current in a motor is achieved by the motor control system. Specifically, the motor control system includes: speed loop P I controller (hereinafter speed controller), d-axis proportional resonance controller, q-axis proportional resonance controller, load disturbance sliding mode observer, gain operator module, differential operator module, IPARK conversion module, inverter, CLARK conversion module, PARK conversion module, position sensor, SVPWM module, inverter and motor.

Alternatively, the type of motor is not particularly limited in the present application, and the motor of the present application may be a permanent magnet synchronous motor, but may be another type of motor. The motor is hereinafter referred to as a permanent magnet synchronous motor.

Specifically, the specific process flow of the motor control system of the present application is as follows:

the position sensor acquires the actual angle theta of the permanent magnet synchronous motor, and the actual rotating speed omega of the motor is obtained through a differential operator _r 。

Given speed ω of permanent magnet synchronous motor _r * And the obtained actual rotation speed omega _r Is input to the speed loop P I controller, and the speed loop P I controls the q-axis given current i output thereof _q * The method comprises the steps of carrying out a first treatment on the surface of the Employing i _d * Vector control method of=0, d-axis given current i _d *＝0。

The actual output current of the inverter (namely three-phase alternating current) is output by the CLARK conversion module _α 、i _β As input of the PARK conversion module, the PARK conversion module outputs d-axis actual current i _d And q-axis actual current i _q 。

The q-axis actual current i _q And actual rotation speed omega _r Obtaining a load torque observation value through a load disturbance sliding mode observer Obtaining load disturbance compensation current i through gain operator _comp The method comprises the steps of carrying out a first treatment on the surface of the Let the q-axis give the current i _q * Compensating current i with load disturbance _comp Added to the q-axis actual current i _q Phase difference to obtain q-axis current error e _q ，e _q Input to a q-axis proportional resonance controller to obtain a q-axis given voltage u _q * The method comprises the steps of carrying out a first treatment on the surface of the Giving electricity to the d axisStream i _d * With d-axis actual current i _d Phase difference to obtain d-axis current error e _d ，e _d Input to a d-axis proportional resonance controller to obtain d-axis given voltage u _d *。

Let the q-axis be given a voltage u _q * Given voltage u with d-axis _d * As input of IPARK conversion module, the IPARK conversion module outputs given voltage corresponding to two-phase stationary coordinate axis, namely a given voltage u of alpha-axis _α * And beta axis given voltage u _β * The method comprises the steps of carrying out a first treatment on the surface of the The obtained alpha-axis given voltage u _α * And beta axis given voltage u _β * And the signals are transmitted to a permanent magnet synchronous motor through an SVPWM algorithm and an inverter to generate corresponding PWM driving signals, so that the inverter is controlled to output voltage signals, and driving of the motor and suppression of current harmonic waves are realized.

The motor control method of the present application will be described in detail below.

As shown in fig. 2, in the first embodiment of the present application, the motor control method of the present application is applied to the motor control system shown in fig. 1. Specifically, the motor control method of the present application includes the steps of:

step S110, determining q-axis load disturbance compensation current according to the actual rotating speed of the motor and the q-axis actual current.

In this embodiment, the measuring modes of the actual rotation speed of the motor include a mechanical velocimetry, an optoelectronic velocimetry and an electromagnetic velocimetry, and the corresponding measuring method of the actual rotation speed of the motor can be selected according to different types of motors. The actual rotational speed of the motor is illustratively measured directly using a mechanical speed measuring device. The method generally uses mechanical elements such as gears, gratings and the like to measure, and has higher precision, but an additional measuring device is required to be installed, so that the operation of the motor can be influenced to a certain extent. Alternatively, the motor rotational speed is measured using a photosensor. In the method, a photoelectric sensor is arranged on a motor shaft, and when the motor rotates, the sensor receives an optical signal on the motor shaft, so that the rotating speed is calculated. The method has higher precision and has no influence on the operation of the motor. Alternatively, the motor speed is measured using the principle of electromagnetic induction. According to the method, the electromagnetic induction device is arranged on the motor shaft, and when the motor rotates, the induction device receives a magnetic field signal on the motor shaft, so that the rotating speed is calculated. This method is accurate but requires the installation of additional measuring devices.

Optionally, the motor control system further comprises a position sensor, wherein the position sensor is used for collecting the actual angle of the motor, and the actual angle is input into the differential operator module to conduct differential operation, so that the actual rotating speed of the motor is obtained.

In this embodiment, the q-axis actual current is obtained by sequentially passing the three-phase ac output from the transformer through the CLARK conversion module and the PARK conversion module. In the inverter control system, a CLARK conversion module converts three-phase alternating current output from a transformer from a three-phase coordinate system to current in a two-phase coordinate system. Next, the PARK transformation module further converts the current in the two-phase coordinate system into a current in the rotated d-q coordinate system, i.e., a d-axis actual current and a q-axis actual current. The PARK transformation is a transformation method of converting a current or voltage in a stationary coordinate system into a current or voltage in a rotating coordinate system, which considers a rotation angle of a motor so that the transformed d-axis and q-axis currents are related to a rotation state of the motor. Through the transformation process, the d-axis current and the q-axis current can be conveniently controlled, and the accurate control of the permanent magnet synchronous motor is further realized.

In this embodiment, the motor current harmonic content is affected by load disturbances. There is a fluctuation in the motor speed, and therefore, it is necessary to determine a load disturbance compensation current for subsequently correcting a current error between a given current and an actual current, reducing the influence of the motor speed fluctuation.

And step S120, compensating the q-axis given current according to the q-axis load disturbance compensation current, and determining a q-axis current error between the q-axis given current after compensation and the q-axis actual current.

In motor control systems, the d-axis actual current is typically considered to be a direct-axis current, while the q-axis actual current is considered to be a quadrature-axis current. This is because the d-axis current is mainly affected by the direct-axis inductance, while the q-axis actual current is mainly affected by the quadrature-axis inductance. In the motor control system, it is generally necessary to suppress the q-axis actual current to reduce torque ripple and electromagnetic noise when the motor is operated, because a change in the q-axis actual current causes a change in the motor torque, thereby affecting the operation stability of the motor. The d-axis actual current is generally regarded as the current corresponding to the back electromotive force generated by the direct-axis inductance, and the current generally does not influence the torque of the motor in the running process of the motor. Therefore, in the motor control system, the d-axis actual current is not normally suppressed, and the q-axis actual current is normally suppressed. Therefore, the q-axis load disturbance compensation current is determined, and the q-axis given current is compensated through the q-axis load disturbance compensation current, so that errors between the q-axis actual current and the q-axis given current are reduced, the influence of load disturbance on the current harmonic content of the motor can be reduced, and the finally obtained driving signal of the motor is more accurate.

In this embodiment, the q-axis load disturbance compensation current is added to the q-axis given current to obtain a compensated q-axis given current, and the compensated q-axis given current is subtracted from the q-axis actual current to obtain a q-axis current error, where the following calculation formula is adopted:

wherein e _q For q-axis current error, i _q * For a given current on the q-axis, i _comp Compensating current for q-axis load disturbance, i _q Is the q-axis actual current.

And step S130, determining a q-axis given voltage according to the q-axis current error.

In this embodiment, after the q-axis current error is obtained, it may be input to the q-axis current loop proportional resonant controller to determine the q-axis given voltage. The operating principle of the current loop proportional resonance controller is based on the characteristics of the resonance circuit. The resonant circuit has lower impedance at a specific frequency, and can amplify or inhibit a signal of the specific frequency. The proportional resonant controller utilizes this characteristic to perform harmonic suppression of the q-axis current error. The proportional resonant controller is generally composed of a resonant circuit and a proportional control part. The resonant circuit is a bandpass filter that can select a particular frequency for amplification or rejection. The proportion control part adjusts according to the magnitude and frequency of the current and controls the amplification or inhibition degree of the resonant circuit. By adjusting the frequency and amplification or suppression degree of the resonant circuit, harmonic components in the current can be effectively suppressed.

Alternatively, the current harmonics of different frequencies may be suppressed by adjusting the resonant frequency in the current loop proportional resonant controller. For example, by setting the resonance frequency to the six fundamental frequencies of the system, the fifth and seventh harmonics in the phase currents can be suppressed.

And step S140, controlling an inverter to output a driving signal of the motor according to the q-axis given voltage and the d-axis given voltage.

In this embodiment, the obtained q-axis given voltage and d-axis given voltage may be sequentially converted by the IPARK conversion module, the SVPWM module, and the inverter, to obtain a driving signal of the motor.

In this embodiment, the driving signal of the motor may be a three-phase alternating voltage.

According to the technical scheme, the q-axis load disturbance compensation current is determined according to the actual rotating speed of the motor and the q-axis actual current; compensating a q-axis given current according to the q-axis load disturbance compensation current, and determining a q-axis current error between the compensated q-axis given current and the q-axis actual current; determining a q-axis given voltage from the q-axis current error; and controlling an inverter to output a driving signal of the motor according to the q-axis given voltage and the d-axis given voltage. According to the actual rotating speed of the motor and the q-axis actual current, the q-axis load disturbance compensation current is determined, and the q-axis given current is compensated by the q-axis load disturbance compensation current, so that the error between the q-axis actual current and the q-axis given current is reduced, the influence of load disturbance on the current harmonic content of the motor can be reduced, and the finally obtained driving signal of the motor is more accurate.

Further, based on the first embodiment, in a second embodiment of the present application, a motor control system includes: the load disturbance sliding mode observer and gain operator module, referring to fig. 3, step S110 includes:

and S111, inputting the actual rotating speed and q-axis actual current of the motor into the load disturbance sliding mode observer to obtain a load torque observation value.

In this embodiment, the load disturbance synovial observer estimates motor speed and position by introducing a load disturbance signal. Firstly, a synovial membrane observer estimates the rotating speed and the position of a motor by measuring the current and the voltage of the motor and combining a mathematical model of the motor. In this process, the synovial membrane observer generates a synovial membrane signal based on the motor current and voltage signals, as well as estimates of motor speed and position. The load disturbance synovial observer then introduces a load disturbance signal into the synovial signal of the synovial observer. The load disturbance signal may be a signal such as a load current, a load voltage, etc. of the motor, or may be another signal related to the load of the motor. By introducing the load disturbance signal, the load disturbance synovial membrane observer can estimate the rotating speed and the position of the motor more accurately, and thus a load torque observation value is obtained. This is because the load disturbance signal may reflect the actual operating state of the motor, thereby helping the synovial observer to better estimate motor speed and position. It should be noted that the performance of the load disturbance synovial observer depends on the choice and manner of processing of the load disturbance signal. Therefore, in practical applications, a suitable load disturbance signal and processing mode need to be selected according to a specific motor type and an operation environment, so as to obtain an optimal estimation effect.

And step S112, inputting the load torque observation value into the gain operator module for calculation to obtain the q-axis load disturbance compensation current.

In this embodiment, the gain operator module is used to amplify or reduce the amplitude of the signal, typically to adjust the amplitude of the output or input signal of the system, thereby changing the performance of the system. In a proportional resonance controller, a gain operator may be used to adjust the torque coefficient, thereby affecting the control accuracy and stability of the system. The magnitude of the load disturbance compensation current can be changed by adjusting the torque coefficient, so that the accurate control of the motor current is realized. It should be noted that the torque coefficient in the gain operator needs to be adjusted according to the actual requirement to obtain the optimal control effect. Meanwhile, when selecting the gain algorithm, the influence of the gain algorithm on the system performance needs to be considered so as to ensure the stability and reliability of the system.

Optionally, step S111 includes:

and S1111, inputting the actual rotation speed and q-axis actual current of the motor into a load disturbance sliding mode observer, and calculating based on a sliding mode control function in the load disturbance sliding mode observer to obtain the load torque observation value.

In this embodiment, the load disturbance sliding mode observer is expressed as:

where λ represents the approach law parameter and s is the slip plane.

The construction process of the load disturbance sliding mode observer is described in detail below:

firstly, a mechanical motion equation of the permanent magnet synchronous motor is established, and an initial load disturbance sliding mode observer is established based on the mechanical motion equation.

Specifically, related parameters of the permanent magnet synchronous motor are obtained, a mechanical motion equation of the permanent magnet synchronous motor is established, and the related parameters comprise the actual rotating speed omega of the permanent magnet synchronous motor _r Moment of inertia J, permanent magnet flux linkage phi _f Motor pole pair number p, load torque T _L Coefficient of resistance friction B, d shaft actual current i _d Actual current on q axis i _d D-axis inductance L _d And q-axis inductance L _q 。

The mechanical motion equation expression of the permanent magnet synchronous motor is as follows:

wherein T is _e Is electromagnetic torque.

T _e Can be further expressed as:

since i is adopted _d =0 vector control, the torque expression can be rewritten as:

and (3) rewriting a mechanical motion equation of the permanent magnet synchronous motor in the formula (1) to obtain a state equation:

where δ represents the derivative of the load torque.

Discretizing the formula (4) to obtain:

according to the formula (5), obtaining an initial load disturbance sliding mode observer is as follows:

second, a sliding mode control function is designed.

The rotational speed estimation error is selected as a linear sliding mode surface, expressed as:

designing a sliding mode approach law, wherein the expression is as follows:

and (3) combining the formula (6) and the formula (8) to obtain a sliding mode control function:

thirdly, obtaining the load disturbance sliding mode observer based on the sliding mode control function and the initial load disturbance sliding mode observer.

Substituting the sliding mode control function into the (6) to obtain a load disturbance sliding mode observer expressed as:

according to the technical scheme, the load disturbance sliding-mode observer is designed, and the load disturbance sliding-mode observer estimates the motor rotation speed and the motor position by introducing the load disturbance signal, so that the sliding-mode observer is helped to estimate the motor rotation speed and the motor position better.

Optionally, step S112 includes:

step S1121, inputting the load torque observation value into the gain operator module, and calculating to obtain the q-axis load disturbance compensation current based on the gain operator in the gain operator module.

In this embodiment, the gain operator is expressed as:

wherein K is _e As a coefficient of torque,is a load torque observation.

In the present embodiment, when the torque coefficient increases, the q-axis load disturbance compensation current becomes smaller, and when the torque coefficient decreases, the q-axis load disturbance compensation current increases, thereby achieving adjustment of the load disturbance compensation current.

Further, based on the first embodiment, in a third embodiment of the present application, the motor control system further includes: the speed loop controller, referring to fig. 4, further includes, before step S120:

step S210, obtaining a given speed of the motor.

In this embodiment, the given speed, i.e., the desired speed, may be set according to the actual situation of the motor.

Step S220, determining a speed difference according to the given speed and the actual speed of the motor.

In this embodiment, the given speed and the actual speed are differenced to obtain a speed difference.

And step S230, inputting the speed difference value into the speed loop controller to obtain the q-axis given current.

In the present embodiment, the speed loop controller used is a proportional-integral controller, which is a linear controller that forms a control deviation based on a given value and an actual output value, and forms a control amount by linearly combining the proportional and integral of the deviation, so as to control the motor. The speed difference is input into the speed loop controller, and the q-axis given current is obtained by adjusting the proportional factor and the integral factor in the speed loop controller and is used for being subsequently converted into a driving signal of the motor to control the motor.

Optionally, the motor control system further comprises: the q-axis proportional resonance controller, step S130 includes:

and S131, inputting the q-axis current error into the q-axis proportional resonance controller, and calculating the q-axis given voltage according to the q-axis current error and a transfer function.

In this embodiment, the calculation formula corresponding to the q-axis given voltage is expressed as:

wherein e _q For q-axis current error, G _PR (s) is a transfer function.

Optionally, the transfer function is expressed as:

wherein k is _pr Is a proportionality coefficient, k _ir Is the resonance coefficient omega _c Is bandwidth omega _n For the resonant frequency by adjusting the resonant frequency omega _n To suppress harmonic currents of different frequencies.

Further, based on the first embodiment, in a fourth embodiment of the present application, the motor control system further includes: the d-axis proportional resonance controller, referring to fig. 5, further includes, before step S140:

step S310, obtaining d-axis given current and d-axis actual current.

And step S320, determining a d-axis current error according to the d-axis given current and the d-axis actual current.

And step S330, inputting the d-axis current error into the d-axis proportional resonance controller, and calculating the d-axis given voltage according to the d-axis current error and a transfer function.

In this embodiment, the calculation formula corresponding to the d-axis given voltage is expressed as:

wherein e _d For q-axis current error, G _PR (s) is a transfer function.

Optionally, the transfer function is expressed as:

Further, based on the first embodiment, in a fifth embodiment of the present application, the motor control system further includes: the IPARK conversion module and the SVPWM module, referring to fig. 6, step S140 includes:

and step S141, inputting the d-axis given voltage and the q-axis given voltage into an IPARK conversion module to obtain the alpha-axis given voltage and the beta-axis given voltage under a two-phase coordinate system.

And step S142, inputting the alpha-axis given voltage and the beta-axis given voltage into an SVPWM module to obtain a space vector voltage signal.

In this embodiment, after the IPARK transformation, a corresponding voltage vector can be obtained through the SVPWM algorithm, and the voltage vector is used to drive the permanent magnet synchronous motor.

SVPWM (Space Vector Pulse Width Modulation) is a space vector pulse width modulation method that can be used to generate a voltage vector that drives a permanent magnet synchronous motor. After IPARK conversion, the three-phase voltages or currents of the motor may be represented as values in the αβ coordinate system, which are then converted into corresponding space vector voltage signals using the SVPWM algorithm.

The basic principle of the SVPWM algorithm is to convert three-phase voltage or current signals into two orthogonal vector signals (α and β), and then generate space vector voltage signals that can drive the motor to rotate by Pulse Width Modulating (PWM) the vector signals. The algorithm can generate different space vector voltage signals by adjusting the pulse width and the switching state of PWM, thereby realizing the accurate control of the motor.

And step S143, inputting the space vector voltage signal into an inverter to obtain a driving signal of the motor.

In this embodiment, after the space vector voltage signal is obtained, the voltage vector passes through an inverter, and the inverter functions to convert a direct current power source into an alternating current power source so as to drive the permanent magnet synchronous motor. The inverter is generally composed of a plurality of switching devices, and by controlling the on-off states of the switching devices, a driving signal corresponding to a voltage vector, such as a three-phase alternating voltage, can be generated. Finally, the driving signal output by the inverter is applied to the three-phase stator winding of the permanent magnet synchronous motor, so that the motor is driven to rotate, and the accurate control of the motor is realized.

Further, based on the first embodiment, in a sixth embodiment of the present application, the motor control system further includes: the CLARK conversion module, PARK conversion module, and inverter, referring to fig. 7, further includes, before step S110:

In step S410, three-phase ac of the inverter in the three-phase coordinate system is obtained.

And step S420, inputting the three-phase alternating current into a CLARK conversion module to obtain alpha-axis current and beta-axis current under a two-phase coordinate system.

And S430, passing the alpha-axis current and the beta-axis current through a PARK conversion module to obtain a d-axis actual current and a q-axis actual current under a rotating d-q coordinate system.

In the present embodiment, the CLARK conversion is a conversion method of converting a current or voltage in a three-phase coordinate system into a current or voltage in a two-phase coordinate system. In the motor control system, a CLARK conversion module converts three-phase alternating current of an inverter in a three-phase coordinate system from the three-phase coordinate system to currents in a two-phase coordinate system, namely an alpha-axis current and a beta-axis current. The PARK transformation module then further converts the α -axis and β -axis currents in the two-phase coordinate system into currents in the rotated d-q coordinate system, i.e., the d-axis actual current and the q-axis actual current. The PARK transformation is a transformation method of converting a current or voltage in a stationary coordinate system into a current or voltage in a rotating coordinate system, which considers a rotation angle of a motor so that the transformed d-axis and q-axis currents are related to a rotation state of the motor. Through the transformation process, the d-axis actual current and the q-axis actual current can be conveniently realized, and further, the accurate control of the permanent magnet synchronous motor is realized.

In a seventh embodiment of the present application, a motor control method of the present application includes:

(1) Acquiring three-phase alternating current of an inverter under a three-phase coordinate system; inputting the three-phase alternating current into a CLARK conversion module to obtain alpha-axis current and beta-axis current under a two-phase coordinate system; and passing the alpha-axis current and the beta-axis current through a PARK transformation module to obtain d-axis actual current and q-axis actual current under a rotating d-q coordinate system. Meanwhile, acquiring the actual angle of the motor through a position sensor; and inputting the actual angle into a differential operator module for differential operation to obtain the actual rotating speed of the motor.

(2) Inputting the actual rotating speed and q-axis actual current of the motor into the load disturbance sliding mode observer to obtain a load torque observation value; and inputting the load torque observation value into the gain operator module for calculation to obtain the q-axis load disturbance compensation current. Simultaneously, acquiring a given speed of the motor; determining a speed difference based on the given speed and an actual speed of the motor; and inputting the speed difference value into the speed loop controller to obtain the q-axis given current.

(3) And compensating the q-axis given current according to the q-axis load disturbance compensation current, and determining a q-axis current error between the q-axis given current after compensation and the q-axis actual current. Simultaneously, obtaining d-axis given current and d-axis actual current; and determining a d-axis current error according to the d-axis given current and the d-axis actual current.

(4) And inputting the q-axis current error into the q-axis proportional resonance controller, and calculating the q-axis given voltage according to the q-axis current error and a transfer function. And simultaneously, inputting the d-axis current error into the d-axis proportional resonance controller, and calculating the d-axis given voltage according to the d-axis current error and a transfer function.

(5) Inputting the d-axis given voltage and the q-axis given voltage into an IPARK conversion module to obtain alpha-axis given voltage and beta-axis given voltage under a two-phase coordinate system; inputting the alpha-axis given voltage and the beta-axis given voltage into an SVPWM module to obtain a space vector voltage signal; and inputting the space vector voltage signal into an inverter to obtain a driving signal of the motor.

According to the technical scheme, the current loop controller adopts the proportional resonance controller to restrain current harmonic waves in the current of the permanent magnet synchronous motor; in order to reduce the influence of load disturbance on the current harmonic content of the motor, the application also designs a load disturbance sliding mode observer based on a novel sliding mode rate, and the estimated load disturbance can be converted into current to be fed forward to a current loop, so that the speed fluctuation is reduced, and meanwhile, the current harmonic can be restrained.

The present embodiments provide embodiments of motor control methods, it being noted that although a logic sequence is shown in the flow diagrams, in some cases the steps shown or described may be performed in a different order than that shown or described herein.

As shown in fig. 8, the motor control device provided in the present application includes:

the load disturbance compensation current determination module 10 is configured to determine a q-axis load disturbance compensation current according to an actual rotation speed of the motor and the q-axis actual current.

A q-axis current error determination module 20 for compensating a q-axis given current according to the q-axis load disturbance compensation current and determining a q-axis current error between the compensated q-axis given current and the q-axis actual current.

A q-axis given voltage determination module 30 for determining a q-axis given voltage from the q-axis current error;

a driving signal determining module 40 for controlling the inverter to output a driving signal of the motor according to the q-axis given voltage and the d-axis given voltage.

The specific implementation manner of the motor control device is basically the same as that of each embodiment of the motor control method, and is not repeated here.

Based on the same inventive concept, the embodiments of the present application further provide a computer readable storage medium, where the computer readable storage medium stores a motor control program, where the motor control program, when executed by a processor, implements each step of the motor control method as described above, and can achieve the same technical effects, so that repetition is avoided, and no further description is given here.

Because the storage medium provided in the embodiments of the present application is a storage medium used for implementing the method in the embodiments of the present application, based on the method described in the embodiments of the present application, a person skilled in the art can understand the specific structure and the modification of the storage medium, and therefore, the description thereof is omitted herein. All storage media used in the methods of the embodiments of the present application are within the scope of protection intended in the present application.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or system. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or system that comprises the element.

The foregoing embodiment numbers of the present application are merely for describing, and do not represent advantages or disadvantages of the embodiments.

From the above description of the embodiments, it will be clear to those skilled in the art that the above-described embodiment method may be implemented by means of software plus a necessary general hardware platform, but of course may also be implemented by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art in the form of a software product stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) as described above, including several instructions for causing a terminal device (which may be a mobile phone, a computer, a server, a television, or a network device, etc.) to perform the method described in the embodiments of the present application.

The foregoing description is only of the preferred embodiments of the present application, and is not intended to limit the scope of the claims, and all equivalent structures or equivalent processes using the descriptions and drawings of the present application, or direct or indirect application in other related technical fields are included in the scope of the claims of the present application.

Claims

1. A motor control method for a motor control system, the motor control method comprising:

determining a q-axis given voltage from the q-axis current error;

2. The motor control method according to claim 1, wherein the motor control system includes: the step of determining q-axis load disturbance compensation current according to the actual rotating speed of the motor and the q-axis actual current comprises the following steps of:

3. The motor control method as claimed in claim 2, wherein the step of inputting the actual rotational speed and q-axis actual current of the motor into the load disturbance slip-mode observer to obtain the load torque observation value comprises:

where λ represents the approach law parameter and s is the slip plane.

4. The motor control method of claim 2, wherein the step of inputting the load torque observation value to the gain operator module for calculation to obtain the q-axis load disturbance compensation current includes:

wherein K is _e As a coefficient of torque,is a load torque observation.

5. The motor control method of claim 1, wherein the motor control system further comprises: the speed loop controller compensates a q-axis given current according to the q-axis load disturbance compensation current, and further includes, before the step of determining a q-axis current error between the compensated q-axis given current and the q-axis actual current:

acquiring a given speed of the motor;

6. The motor control method of claim 5, wherein the motor control system further comprises: the q-axis proportional resonance controller, the step of determining a q-axis given voltage from the q-axis current error includes:

wherein e _q For q-axis current error, G _PR (s) is a transfer function.

7. The motor control method of claim 1, wherein the motor control system further comprises: the d-axis proportional resonance controller, before the step of controlling the inverter to output the driving signal of the motor according to the q-axis given voltage and the d-axis given voltage, further comprises:

acquiring d-axis given current and d-axis actual current;

wherein e _d For q-axis current error, G _PR (s) is a transfer function.

8. The motor control method according to claim 6 or 7, characterized in that the transfer function is expressed as:

9. The motor control method of claim 1, wherein the motor control system further comprises: the step of controlling an inverter to output a driving signal of the motor according to the q-axis given voltage and the d-axis given voltage includes:

10. The motor control method of claim 1, wherein the motor control system further comprises: the step of determining the q-axis load disturbance compensation current according to the actual rotating speed of the motor and the q-axis actual current further comprises the following steps:

11. A motor control device, characterized in that the motor control device comprises:

12. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a motor control program which, when executed by a processor, implements the steps of the motor control method of any one of claims 1-10.