阅读说明：本技术 电机转矩脉动抑制方法、装置以及电机控制器、存储介质 (Motor torque ripple suppression method, motor torque ripple suppression device, motor controller and storage medium ) 是由 李荷洁 于 2020-05-13 设计创作，主要内容包括：本发明提出一种电机转矩脉动抑制方法、装置以及电机控制器、存储介质,其中,方法包括：在电机运行过程中,获取电机当前时刻的电角度及实际转速；根据实际转速与当前给定的转速,确定电机当前的转速波动值；根据当前的转速波动值及电流环调制频率,确定当前的交轴电流补偿值；根据预设的关键电角度与交轴电流的映射关系,确定与当前时刻的电角度对应的待补偿的交轴电流；利用当前的交轴电流补偿值,对待补偿的交轴电流进行补偿；根据补偿后的交轴电流值,对电机进行驱动。该方法通过根据电机的电角度、转速以及电流环调制频率对待补偿的交轴电流进行补偿,从而能够在电机的负载转矩变化的情况下,降低交轴电流的脉动实现对电机转矩脉动的抑制。(The invention provides a motor torque ripple suppression method and device, a motor controller and a storage medium, wherein the method comprises the following steps: in the running process of the motor, acquiring the current electric angle and the actual rotating speed of the motor; determining the current rotation speed fluctuation value of the motor according to the actual rotation speed and the current given rotation speed; determining a current quadrature axis current compensation value according to the current rotating speed fluctuation value and the current loop modulation frequency; determining quadrature axis current to be compensated corresponding to the electrical angle at the current moment according to a preset mapping relation between the key electrical angle and the quadrature axis current; compensating the quadrature axis current to be compensated by using the current quadrature axis current compensation value; and driving the motor according to the compensated quadrature axis current value. According to the method, the quadrature axis current to be compensated is compensated according to the electrical angle, the rotating speed and the current loop modulation frequency of the motor, so that the ripple of the quadrature axis current is reduced under the condition that the load torque of the motor is changed, and the suppression of the torque ripple of the motor is realized.)

1. A method of suppressing torque ripple of a motor, comprising:

in the running process of the motor, acquiring the current electric angle and the actual rotating speed of the motor;

determining the current rotation speed fluctuation value of the motor according to the actual rotation speed and the current given rotation speed;

determining a current quadrature axis current compensation value according to the current rotating speed fluctuation value and the current loop modulation frequency;

determining quadrature axis current to be compensated corresponding to the electrical angle at the current moment according to a preset mapping relation between the key electrical angle and the quadrature axis current;

compensating the quadrature axis current to be compensated by using the current quadrature axis current compensation value;

and driving the motor according to the compensated quadrature axis current value.

2. The method of claim 1, wherein determining a current quadrature axis current compensation value based on the current speed ripple value and current loop modulation frequency comprises:

according toDetermining the current quadrature axis current compensation value,

wherein, Δ i_qIs the current quadrature axis current compensation value, delta n is the rotating speed fluctuation value, f_sampThe frequency is modulated for the current loop.

3. The method according to claim 1 or 2, wherein before the compensating the quadrature axis current to be compensated, further comprising:

acquiring the electrical frequency of the motor when the motor runs at the minimum rotating speed;

dividing each electrical cycle of the motor into intervals according to the ratio of the current loop modulation frequency to the electrical frequency so as to determine each key electrical angle contained in each electrical cycle;

determining quadrature axis current reference values corresponding to the key electrical angles according to quadrature axis current curves corresponding to the motor under the current load;

the compensation of the quadrature axis current to be compensated comprises the following steps:

and respectively compensating a first cross-axis current corresponding to the first boundary angle value and a second cross-axis current corresponding to the second boundary angle value of the angle interval.

4. The method of claim 3, wherein said dividing each electrical cycle of the motor into intervals according to the ratio of the current loop modulation frequency to the electrical frequency comprises:

rounding the ratio of the current loop modulation frequency to the electrical frequency to determine the number a of intervals contained in each electrical cycle;

according toDetermining the angle range corresponding to each interval;

and determining each key electrical angle contained in each electrical cycle according to the angle range corresponding to each interval.

5. The method of claim 3, wherein the compensating for the first quadrature axis current corresponding to the first boundary angle value and the second quadrature axis current corresponding to the second boundary angle value of the angular range comprises:

according toCompensating a first quadrature axis current corresponding to the first boundary angle value;

according toCompensating a second quadrature axis current corresponding to the second boundary angle value,

wherein, Δ i_qyIs a compensation value of the first quadrature axis current, Δ i_qCompensating for current quadrature currentValue of theta_xIs the electrical angle at the present moment, θ_yIs a first boundary angle value, θ_y+1Is the second boundary angle value, Δ i_qy+1Is the compensation value of the second quadrature axis current.

6. A motor torque ripple suppression device, characterized by comprising:

the acquisition module is used for acquiring the current electric angle and the actual rotating speed of the motor in the running process of the motor;

the determining module is used for determining the current rotating speed fluctuation value of the motor according to the actual rotating speed and the current given rotating speed; the current quadrature axis current compensation value is determined according to the current rotating speed fluctuation value and the current loop modulation frequency; the quadrature axis current compensation device is used for determining the quadrature axis current to be compensated corresponding to the electrical angle at the current moment according to the mapping relation between the preset key electrical angle and the quadrature axis current;

the compensation module is used for compensating the quadrature axis current to be compensated by utilizing the current quadrature axis current supplement value;

and the driving module is used for driving the motor according to the compensated quadrature axis current value after compensating the quadrature axis current to be compensated.

7. The apparatus of claim 6, wherein the obtaining module is further configured to:

acquiring the electrical frequency of the motor when the motor runs at the minimum rotating speed;

dividing each electrical cycle of the motor into intervals according to the ratio of the current loop modulation frequency to the electrical frequency so as to determine each key electrical angle contained in each electrical cycle;

determining quadrature axis current reference values corresponding to the key electrical angles according to quadrature axis current curves corresponding to the motor under the current load;

the compensation module is specifically configured to:

and respectively compensating a first cross-axis current corresponding to the first boundary angle value and a second cross-axis current corresponding to the second boundary angle value of the angle interval.

8. A motor controller, comprising:

at least one processor; and

a memory communicatively coupled to the at least one processor;

wherein the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the motor torque ripple suppression method of any one of claims 1-5.

9. A readable storage medium, having stored thereon a motor torque ripple suppression program that, when executed by a processor, implements a motor torque ripple suppression method according to any one of claims 1 to 5.

Technical Field

The invention relates to the technical field of motors, in particular to a motor torque ripple suppression method and device, a motor controller and a storage medium.

Background

In the case of a permanent magnet synchronous motor, due to the installation of a rotor permanent magnet and the existence of a stator tooth slot, a back electromotive force of the permanent magnet synchronous motor has certain non-sine degree, and harmonic waves are contained in a stator current output by an inverter, so that electromagnetic torque output by the motor generates pulsation, and the rotation speed fluctuation, noise and mechanical vibration of the motor are caused, thereby limiting the application of the motor in a high-precision system and a speed regulation system.

In the related art, the inverter dead zone compensation method is mainly adopted to compensate the phase current of the motor so as to reduce the content of the fiftieth harmonic, so as to suppress the torque ripple of the motor, and the scheme requires that the load is constant (namely, the phase current is kept unchanged). However, for the compressor load, the load torque in the unit operation period changes at any time, the magnitude of the motor phase current changes at any time, and the dead zone compensation method is difficult to realize, so how to suppress the motor torque ripple when the load torque changes is a problem to be solved in the field.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art.

Therefore, a first object of the present invention is to provide a method for suppressing motor torque ripple, which can reduce ripple of quadrature axis current to suppress motor torque ripple when load torque of a motor varies by compensating the quadrature axis current to be compensated according to an electrical angle, a rotation speed and a current loop modulation frequency of the motor.

A second object of the present invention is to provide a motor torque ripple suppression device.

A third object of the present invention is to provide a motor controller.

A fourth object of the invention is to propose a readable storage medium.

In order to achieve the above object, an embodiment of a first aspect of the present invention provides a motor torque ripple suppression method, including: in the running process of the motor, acquiring the current electric angle and the actual rotating speed of the motor; determining the current rotation speed fluctuation value of the motor according to the actual rotation speed and the current given rotation speed; determining a current quadrature axis current compensation value according to the current rotating speed fluctuation value and the current loop modulation frequency; determining quadrature axis current to be compensated corresponding to the electrical angle at the current moment according to a preset mapping relation between the key electrical angle and the quadrature axis current; compensating the quadrature axis current to be compensated by using the current quadrature axis current compensation value; and driving the motor according to the compensated quadrature axis current value.

According to the method for suppressing the motor torque ripple, firstly, in the motor operation process, the current electric angle and the actual rotating speed of the motor are obtained, then the current rotating speed fluctuation value of the motor is determined according to the actual rotating speed and the current given rotating speed, the current quadrature axis current compensation value is further determined according to the current rotating speed fluctuation value and the current loop modulation frequency, the quadrature axis current to be compensated corresponding to the current electric angle is determined according to the preset mapping relation between the key electric angle and the quadrature axis current, finally the current quadrature axis current compensation value is used for compensating the quadrature axis current to be compensated, and the motor is driven according to the compensated quadrature axis current value. Therefore, the method compensates the quadrature axis current to be compensated according to the electrical angle, the rotating speed and the current loop modulation frequency of the motor, so that the ripple of the quadrature axis current is reduced to suppress the torque ripple of the motor under the condition that the load torque of the motor is changed.

In addition, the motor torque ripple suppression method according to the above embodiment of the present invention may further have the following additional technical features:

according to an embodiment of the present invention, the determining a current quadrature axis current compensation value according to the current rotation speed fluctuation value and the current loop modulation frequency includes: according toDetermining a current quadrature axis current compensation value, wherein Δ i_qIs the current quadrature axis current compensation value, delta n is the rotating speed fluctuation value, f_sampThe frequency is modulated for the current loop.

According to an embodiment of the present invention, before the compensating the quadrature axis current to be compensated, the method further includes: acquiring the electrical frequency of the motor when the motor runs at the minimum rotating speed; dividing each electrical cycle of the motor into intervals according to the ratio of the current loop modulation frequency to the electrical frequency so as to determine each key electrical angle contained in each electrical cycle; determining quadrature axis current reference values corresponding to the key electrical angles according to quadrature axis current curves corresponding to the motor under the current load; the compensation of the quadrature axis current to be compensated comprises the following steps: and respectively compensating a first cross-axis current corresponding to the first boundary angle value and a second cross-axis current corresponding to the second boundary angle value of the angle interval.

According to an embodiment of the present invention, the dividing each electrical cycle of the motor into intervals according to a ratio of the current loop modulation frequency to the electrical frequency includes: rounding the ratio of the current loop modulation frequency to the electrical frequency to determine the number a of intervals contained in each electrical cycle; according toDetermining the angle range corresponding to each interval; and determining each key electrical angle contained in each electrical cycle according to the angle range corresponding to each interval.

According to an embodiment of the present invention, the respectively compensating the first quadrature axis current corresponding to the first boundary angle value and the second quadrature axis current corresponding to the second boundary angle value of the angle range includes: according toCompensating a first quadrature axis current corresponding to the first boundary angle value; according toCompensating a second quadrature axis current corresponding to the second boundary angle value, wherein Δ i_qyIs a compensation value of the first quadrature axis current, Δ i_qFor the present quadrature-axis current compensation value, θ_xIs the electrical angle at the present moment, θ_yIs a first boundaryAngle value, θ_y+1Is the second boundary angle value, Δ i_qy+1Is the compensation value of the second quadrature axis current.

In order to achieve the above object, a second aspect of the present invention provides a motor torque ripple suppression device, including: the acquisition module is used for acquiring the current electric angle and the actual rotating speed of the motor in the running process of the motor; the determining module is used for determining the current rotating speed fluctuation value of the motor according to the actual rotating speed and the current given rotating speed; the current quadrature axis current compensation value is determined according to the current rotating speed fluctuation value and the current loop modulation frequency; the quadrature axis current compensation device is used for determining the quadrature axis current to be compensated corresponding to the electrical angle at the current moment according to the mapping relation between the preset key electrical angle and the quadrature axis current; the compensation module is used for compensating the quadrature axis current to be compensated by utilizing the current quadrature axis current supplement value; and the driving module is used for driving the motor according to the compensated quadrature axis current value after compensating the quadrature axis current to be compensated.

According to the motor torque ripple suppression device provided by the embodiment of the invention, the current electric angle and the actual rotating speed of the motor at the current moment are acquired by the acquisition module in the motor operation process, the current rotating speed fluctuation value of the motor is determined by the determination module according to the actual rotating speed and the current given rotating speed, the current quadrature axis current compensation value is determined according to the current rotating speed fluctuation value and the current loop modulation frequency, the quadrature axis current to be compensated corresponding to the current electric angle is determined according to the preset mapping relation between the key electric angle and the quadrature axis current, and the current quadrature axis current compensation value is utilized by the compensation module to compensate the quadrature axis current to be compensated; after the quadrature axis current to be compensated is compensated through the driving module, the motor is driven according to the compensated quadrature axis current value. Therefore, the device compensates the quadrature axis current to be compensated according to the electrical angle, the rotating speed and the current loop modulation frequency of the motor, so that the ripple of the quadrature axis current is reduced to suppress the torque ripple of the motor under the condition that the load torque of the motor is changed.

In addition, the motor torque ripple suppression device according to the above embodiment of the present invention may further have the following additional technical features:

according to an embodiment of the present invention, the obtaining module is further configured to: acquiring the electrical frequency of the motor when the motor runs at the minimum rotating speed; dividing each electrical cycle of the motor into intervals according to the ratio of the current loop modulation frequency to the electrical frequency so as to determine each key electrical angle contained in each electrical cycle; determining quadrature axis current reference values corresponding to the key electrical angles according to quadrature axis current curves corresponding to the motor under the current load; the compensation module is specifically configured to: and respectively compensating a first cross-axis current corresponding to the first boundary angle value and a second cross-axis current corresponding to the second boundary angle value of the angle interval.

In order to achieve the above object, an embodiment of a third aspect of the present invention provides a motor controller, including: at least one processor; and a memory communicatively coupled to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the motor torque ripple suppression method according to the embodiment of the first aspect of the present invention.

According to the motor controller provided by the embodiment of the invention, when the instructions stored in the memory are executed by the at least one processor, the quadrature axis current to be compensated can be compensated according to the electrical angle, the rotating speed and the current loop modulation frequency of the motor, so that the ripple of the quadrature axis current can be reduced under the condition that the load torque of the motor is changed, and the suppression of the motor torque ripple is realized.

In order to achieve the above object, a third embodiment of the present invention proposes a readable storage medium, on which a motor torque ripple suppression program is stored, which when executed by a processor, implements the motor torque ripple suppression method proposed by the first embodiment of the present invention.

According to the readable storage medium of the embodiment of the invention, when the motor torque ripple suppression program stored on the readable storage medium is executed by the processor, the quadrature axis current to be compensated can be compensated according to the electrical angle, the rotating speed and the current loop modulation frequency of the motor, so that the ripple of the quadrature axis current can be reduced to suppress the motor torque ripple under the condition that the load torque of the motor is changed.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The foregoing and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a flow chart of a motor torque ripple suppression method according to an embodiment of the present invention;

FIG. 2 is a flow chart for determining critical angles of a motor and their corresponding quadrature axis current reference values according to one embodiment of the present invention;

FIG. 3 is a flow chart of interval division for each electrical cycle of the motor according to one example of the present invention;

fig. 4 is a block diagram of a structure of a motor torque ripple suppression device according to an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

A motor torque ripple suppression method, a motor torque ripple suppression device, a motor controller, and a storage medium according to embodiments of the present invention are described below with reference to the accompanying drawings.

Fig. 1 is a flowchart of a motor torque ripple suppression method according to an embodiment of the present invention.

As shown in fig. 1, the method comprises the steps of:

s101, in the running process of the motor, the electric angle and the actual rotating speed of the motor at the current moment are obtained.

The motor is a motor to be inhibited from torque pulsation and is in a running state, and can be a permanent magnet synchronous motor.

Specifically, a constant rotation speed command of the motor can be given to drive the motor to stably operate with load. The given rotating speed is any rotating speed value which is determined according to parameters of the motor and is positioned in a normal operating speed range of the motor, and the load can be a compressor type load. In the running process of the motor, the current electric angle and the actual rotating speed of the motor can be acquired through the signal acquisition device and can be stored in the memory for later calling.

It should be understood that the motor may be controlled to operate in a speed closed loop mode, and specifically, the motor controller may be controlled to operate in a double closed loop mode of a rotating speed outer loop and a current inner loop, where an input of the rotating speed outer loop is a currently given rotating speed, an output of the rotating speed outer loop is a torque value, and a current value is calculated according to the torque value, where the current value is an input of the current inner loop, and the current value is converted into a driving voltage of the motor through the current inner loop to drive the motor to operate.

And S102, determining the current rotation speed fluctuation value of the motor according to the actual rotation speed and the current given rotation speed.

Specifically, the difference between the actual rotation speed and the currently given rotation speed may be calculated, that is, the current rotation speed fluctuation value, and the rotation speed fluctuation value is stored in the memory for subsequent recall.

And S103, determining a current quadrature axis current compensation value according to the current rotating speed fluctuation value and the current loop modulation frequency.

The current loop modulation frequency may be a frequency at which the current inner loop performs PI (Proportional Integral) adjustment, that is, a sampling frequency of the PI regulator.

It should be noted that the ripple of the quadrature axis current may cause the ripple of the motor torque, the ripple of the motor torque may cause the fluctuation of the motor rotation speed, and the current loop modulation frequency is fixed and unchanged, so the current quadrature axis current compensation value may be determined according to the current rotation speed fluctuation value and the current loop modulation frequency, and the quadrature axis current compensation value may be stored in the memory for subsequent calling.

And S104, determining the quadrature axis current to be compensated corresponding to the electrical angle at the current moment according to the preset mapping relation between the key electrical angle and the quadrature axis current.

Wherein the preset key electrical angle may be a plurality of electrical angles in each electrical cycle of the motor.

When the load of the motor is a compressor load, the load torque of the motor (the load torque is equal to the electromagnetic torque when the motor is stably operated) is in positive correlation with the operation electrical angle θ, and the operation of the motor can be controlled by a control method with id equal to 0, according to the formula:

T_e＝p((L_d-L_q)i_di_q+ψ_fi_q) (1)

the electromagnetic torque T can be obtained_eProportional to the quadrature current i_qWherein p is the number of pole pairs of the motor, L_dIs a direct-axis inductor, L_qIs a quadrature axis inductor, i_dIs a direct axis current, i_qFor cross-axis currents, #_fIs a motor flux linkage. Thus, quadrature axis current i of the motor_qAnd the electrical angle theta. Therefore, a preset key electrical angle can be set, and when the motor operates, the corresponding quadrature axis current can be detected at each preset key electrical angle of the motor, so as to obtain the preset key electrical angle (theta)₀,θ₁,θ₂…θ_a) Corresponding quadrature axis current (i)_q0,i_q1,i_q2…i_qa) Wherein each key electrical angle corresponds to a quadrature current, e.g. electrical angle θ₂Corresponding quadrature axis current i_q2The quadrature axis current i of the motor can be constructed according to the mapping relation_qAn electrical angle θ data table, and the data table may be stored in a memory for later recall.

Therefore, in the case that the electrical angle of the motor at the current moment is obtained in step S101, the actual quadrature axis current of the motor at the electrical angle at the current moment may be detected, and then the quadrature axis current to be compensated corresponding to the electrical angle at the current moment may be determined according to the actual quadrature axis current and the mapping relationship.

And S105, compensating the quadrature axis current to be compensated by using the current quadrature axis current compensation value.

Specifically, the calculated current quadrature axis current compensation value is superposed on the quadrature axis current to be compensated so as to realize the compensation of the quadrature axis current and reduce the pulsation of the quadrature axis current.

And S106, driving the motor according to the compensated quadrature axis current value.

Specifically, compared with the quadrature axis current value before compensation, the ripple of the quadrature axis current value after compensation is greatly reduced, and when the motor is driven according to the quadrature axis current value after compensation, the ripple of the motor torque can be inhibited, so that the motor outputs stable electromagnetic torque, and the rotation speed fluctuation, noise and mechanical vibration of the motor are greatly reduced.

Compared with the inverter dead zone compensation method in the related art, the motor torque ripple suppression method in the embodiment of the invention obtains stable electromagnetic torque by reducing the ripple of the quadrature axis current in the running process of the motor on the premise of not increasing the hardware cost, so that the torque ripple of the motor can be suppressed when the load torque changes constantly.

Therefore, the motor torque ripple suppression method acquires the actual rotating speed and the electrical angle of the motor in real time, determines the current compensation value according to the rotating speed fluctuation value and the current loop modulation frequency, and compensates the quadrature axis current to be compensated, so that the quadrature axis current can be compensated in real time under the condition that the load torque of the motor changes, the ripple of the quadrature axis current is reduced, and the suppression of the motor torque ripple is further realized.

It should be noted that, the above steps S101 to S105 of the embodiment of the present invention may respectively correspond to one program, and each program may be stored in the memory for the processor to execute, and when the processor executes the corresponding program in the memory, the above steps S101 to S105 are implemented, so as to implement the method for suppressing the motor torque ripple of the embodiment of the present invention. Besides, the above steps S101 to S105 can be realized by the following embodiments, which are described in detail below:

in an embodiment of the present invention, determining the current quadrature axis current compensation value according to the current rotation speed fluctuation value and the current loop modulation frequency, that is, step S103 may include:

according to the formula:

determining a current quadrature axis current compensation value, wherein Δ i_qFor the current quadrature axis current compensation value, Δ n is the rotation speed fluctuation value, f_sampThe frequency is modulated by the current loop.

In an embodiment of the present invention, as shown in fig. 2, before the compensation of the quadrature axis current to be compensated in step S105, the method further includes the following steps:

s201, acquiring the electrical frequency of the motor when the motor runs at the minimum rotating speed.

Specifically, the following can be expressed according to the formula:

calculating the minimum rotating speed n of the motor_minElectrical frequency f during operation_minWherein p is the pole pair number of the motor.

And S202, dividing each electric cycle of the motor into intervals according to the ratio of the current loop modulation frequency to the electric frequency so as to determine each key electric angle contained in each electric cycle.

Each electrical cycle of the motor is the time for each pair of rotating magnetic poles of the motor to rotate for one turn, and is 360 °, that is, each pair of rotating magnetic poles of the motor corresponds to one electrical cycle of 360 °.

Specifically, first, the current loop modulation frequency f can be calculated_sampWith electrical frequency f_minAccording to the ratio, dividing a complete electric cycle corresponding to each pair of rotating magnetic poles of the motor into a intervals according to the ratio, wherein a is more than or equal to 1, and a is an integer, so that each electric cycle comprises a +1 key electric angles, and the electric cycle can be divided into a intervals and a intervalsAnd storing each key electrical angle in a memory to be used for determining a quadrature axis current reference value corresponding to each key electrical angle subsequently.

And S203, determining quadrature axis current reference values corresponding to the key electrical angles according to the quadrature axis current curves corresponding to the motor under the current load. The quadrature axis current curve refers to an actual quadrature axis current curve tested when the motor operates stably with a load.

It should be noted that, for a motor driving a compressor load to operate, when the motor operates stably in a closed-loop control mode of a rotating speed, a quadrature axis current of the motor changes along with a load torque, and the load torque changes along with an electrical angle of the motor, so that the load torque of the motor can change along with the electrical angle.

Specifically, when the motor runs, a current value obtained according to a torque value output by a rotating speed outer ring can be detected, a quadrature axis current curve corresponding to the current load can be drawn according to the current value, and then each quadrature axis current reference value corresponding to each key electrical angle can be determined according to the quadrature axis current curve.

It is understood that there may be a plurality of quadrature axis current values to be compensated for each quadrature axis current reference value, and after determining each quadrature axis current reference value, each quadrature axis current reference value may be compared with the quadrature axis current i obtained in the above step S104_qComparing each quadrature axis current corresponding to each key electrical angle in the electrical angle θ data table, and if the quadrature axis current reference value is different from the corresponding quadrature axis current, indicating that the quadrature axis current reference value pulsates, which is the quadrature axis current to be compensated.

Correspondingly, the compensation of the quadrature axis current to be compensated in step S105 includes: and respectively compensating a first cross-axis current corresponding to the first boundary angle value and a second cross-axis current corresponding to the second boundary angle value of the angle interval.

Specifically, the current electrical angle θ may be acquired first_xAngle interval (theta)_y，θ_y+1) Wherein, theta_yIs a first boundary angle value, θ_y+1Is a second boundary angle value, and then is usedFront quadrature axis current compensation value delta i_qFor the first boundary angle value theta_yCorresponding first quadrature axis current i_qrefyAnd a second boundary angle value theta_y+1Corresponding second quadrature axis current i_qrefy+1Compensation is performed separately.

Further, as shown in fig. 3, dividing each electrical cycle of the motor into intervals according to the ratio of the current loop modulation frequency to the electrical frequency, that is, the step S202, may include the following steps:

s301, rounding the ratio of the current loop modulation frequency to the electrical frequency to determine the number of intervals a included in each electrical cycle.

Specifically, the following can be expressed according to the formula:

calculating the number of sections a contained in each electric cycle of the motor, wherein f_sampFor the current loop modulation frequency, a is an integer.

S302, according to the formula:

and determining the angle ranges d1 and d2 corresponding to each interval, wherein d is the electrical angle magnitude value corresponding to each interval.

And S303, determining each key electrical angle contained in each electrical cycle according to the angle range corresponding to each interval.

For example, if a is calculated to be 4, that is, each electrical cycle of the motor is divided into 4 sections, the angular ranges d1 and d2 corresponding to each section are 0 ° to 90 °, 90 ° to 180 °, 180 ° to 270 °, and 270 ° to 360 °, respectively, and the electrical angle of each section is 90 °, so that the key electrical angles included in each electrical cycle are 0 °, 90 °, 270 °, and 360 °.

In one example, respectively compensating a first quadrature axis current corresponding to a first boundary angle value and a second quadrature axis current corresponding to a second boundary angle value of the angle range includes:

according to the formula:

compensating a first quadrature axis current corresponding to the first boundary angle value; according to the formula:

compensating a second quadrature axis current corresponding to a second boundary angle value, wherein Δ i_qyIs a compensation value of the first quadrature axis current, Δ i_qFor the present quadrature-axis current compensation value, θ_xIs the electrical angle at the present moment, θ_yIs a first boundary angle value, θ_y+1Is the second boundary angle value, Δ i_qy+1And g is a proportionality coefficient.

Specifically, first, the compensation value Δ i of the first quadrature axis current value is calculated according to the formula (5) and the formula (6), respectively_qyAnd a compensation value delta i of a second quadrature axis current value_qy+1Then, the compensation value delta i of the first quadrature axis current value is calculated_qyAnd a compensation value delta i of a second quadrature axis current value_qy+1Are respectively superposed to the first quadrature axis current i_qrefyAnd a second quadrature axis current i_qrefy+1The above. Namely, the current quadrature axis current compensation value delta i is realized_qProportionally and respectively adding to the first boundary angle value theta_yA second boundary angle value theta_y+1Respectively corresponding first quadrature axis current i_qrefySecond quadrature axis current i_qrefy+1Therefore, the quadrature axis current pulsation is reduced, and the stable electromagnetic torque effect is obtained.

In one example of the present invention, after compensating the quadrature axis current to be compensated, the method further includes: and driving the motor according to the compensated quadrature axis current value.

Specifically, after the quadrature axis current to be compensated is compensated, the compensated quadrature axis current value can be input into the current inner ring, and the compensated quadrature axis current value is converted into the driving voltage of the motor through the current inner ring so as to drive the motor to operate, and at the moment, the electromagnetic torque output by the motor does not pulsate any more.

In summary, according to the method, the quadrature axis current to be compensated is compensated according to the electrical angle, the rotation speed and the current loop modulation frequency of the motor, so that the ripple of the quadrature axis current is reduced to suppress the torque ripple of the motor under the condition that the load torque of the motor is changed.

In order to implement the above embodiments, the present invention further provides a motor torque ripple suppression device. Fig. 4 is a block diagram of a structure of a motor torque ripple suppression device according to an embodiment of the present invention.

As shown in fig. 4, the motor torque ripple suppression device 10 includes an acquisition module 11, a determination module 12, a compensation module 13, and a drive module 14.

The obtaining module 11 is configured to obtain an electrical angle and an actual rotation speed of the motor at a current moment in an operation process of the motor; the determining module 12 is configured to determine a current rotation speed fluctuation value of the motor according to the actual rotation speed and a current given rotation speed; the current quadrature axis current compensation value is determined according to the current rotating speed fluctuation value and the current loop modulation frequency; the system comprises a current sensor, a current controller and a controller, wherein the current sensor is used for detecting the current angle of the current sensor and the current sensor; the compensation module 13 is configured to compensate the quadrature axis current to be compensated by using the current quadrature axis current compensation value; the driving module 14 is configured to drive the motor according to the compensated quadrature axis current value after compensating the quadrature axis current to be compensated.

Specifically, in practical application, firstly, the obtaining module 11 obtains the current electrical angle and the actual rotating speed of the motor in the running process of the motor; then, determining the current rotation speed fluctuation value of the motor according to the actual rotation speed and the current given rotation speed through a determining module 12; determining a current quadrature axis current compensation value according to the current rotating speed fluctuation value and the current loop modulation frequency; determining quadrature axis current to be compensated corresponding to the electrical angle at the current moment according to a preset mapping relation between the key electrical angle and the quadrature axis current; finally, compensating the quadrature axis current to be compensated by the compensation module 13 by using the current quadrature axis current compensation value; after the quadrature axis current to be compensated is compensated, the motor is driven by the driving module 14 according to the compensated quadrature axis current value.

In an embodiment of the present invention, the obtaining module 12 is further configured to: acquiring the electrical frequency of the motor when the motor runs at the minimum rotating speed; according to the ratio of the current loop modulation frequency to the electrical frequency, dividing each electrical cycle of the motor into intervals to determine each key electrical angle contained in each electrical cycle; determining quadrature axis current reference values corresponding to the key electrical angles according to quadrature axis current curves corresponding to the motor under the current load; accordingly, the compensation module 13 may be specifically configured to: and respectively compensating a first cross-axis current corresponding to the first boundary angle value and a second cross-axis current corresponding to the second boundary angle value of the angle interval.

It should be noted that the foregoing explanation of the embodiment of the motor torque ripple suppression method is also applicable to the motor torque ripple suppression device of the embodiment, and is not repeated herein.

According to the motor torque ripple suppression device provided by the embodiment of the invention, the quadrature axis current to be compensated is compensated according to the electrical angle, the rotating speed and the current loop modulation frequency of the motor, so that the ripple of the quadrature axis current is reduced under the condition that the load torque of the motor is changed, and the suppression of the motor torque ripple is realized.

Further, the present invention also provides a motor controller, comprising: at least one processor and a memory communicatively coupled to the at least one processor.

The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the motor torque ripple suppression method according to the embodiment of the first aspect of the present invention.

When the instructions stored in the memory are executed by the at least one processor, the motor controller can compensate the quadrature axis current to be compensated according to the electrical angle, the rotating speed and the current loop modulation frequency of the motor, so that the ripple of the quadrature axis current can be reduced to suppress the torque ripple of the motor under the condition that the load torque of the motor is changed.

In order to implement the above embodiments, the present invention further proposes a readable storage medium, on which a motor torque ripple suppression program is stored, which when executed by a processor implements the motor torque ripple suppression method proposed in the first aspect embodiment of the present invention.

The readable storage medium can compensate the quadrature axis current to be compensated according to the electrical angle, the rotating speed and the current loop modulation frequency of the motor when the motor torque ripple suppression program stored on the readable storage medium is executed by the processor, so that the ripple of the quadrature axis current can be reduced to realize the suppression of the motor torque ripple under the condition that the load torque of the motor changes.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing steps of a custom logic function or process, and alternate implementations are included within the scope of the preferred embodiment of the present invention in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present invention.

The logic and/or steps represented in the flowcharts or otherwise described herein, e.g., an ordered listing of executable instructions that can be considered to implement logical functions, can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For the purposes of this description, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic device) having one or more wires, a portable computer diskette (magnetic device), a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via for instance optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner if necessary, and then stored in a computer memory.

It should be understood that portions of the present invention may be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, any one or combination of the following techniques, which are known in the art, may be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application specific integrated circuit having an appropriate combinational logic gate circuit, a Programmable Gate Array (PGA), a Field Programmable Gate Array (FPGA), or the like.

It will be understood by those skilled in the art that all or part of the steps carried by the method for implementing the above embodiments may be implemented by hardware related to instructions of a program, which may be stored in a computer readable storage medium, and when the program is executed, the program includes one or a combination of the steps of the method embodiments.

In addition, functional units in the embodiments of the present invention may be integrated into one processing module, or each unit may exist alone physically, or two or more units are integrated into one module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. The integrated module, if implemented in the form of a software functional module and sold or used as a stand-alone product, may also be stored in a computer readable storage medium.

The storage medium mentioned above may be a read-only memory, a magnetic or optical disk, etc. Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.