Motor torque pulsation suppression method, device, motor controller, and storage medium

Abstract

The present invention proposes a method, device, motor controller, and storage medium for suppressing motor torque pulsation, wherein the method includes: obtaining the electrical angle and actual speed of the motor at the current moment during the operation of the motor; determining the current speed fluctuation value of the motor according to the actual speed and the current given speed; determining the current quadrature axis current compensation value according to the current speed fluctuation value and the current loop modulation frequency; determining the quadrature axis current to be compensated corresponding to the electrical angle at the current moment according to the mapping relationship between the preset key electrical angle and the quadrature axis current; compensating the quadrature axis current to be compensated using the current quadrature axis current compensation value; and driving the motor according to the compensated quadrature axis current value. The method compensates the quadrature axis current to be compensated according to the electrical angle, speed, and current loop modulation frequency of the motor, thereby reducing the pulsation of the quadrature axis current when the load torque of the motor changes, thereby suppressing the motor torque pulsation.

Description

Technical Field

[0001] The present invention relates to the field of motor technology, and in particular to a method and device for suppressing motor torque pulsation, a motor controller, and a storage medium. Background Art

[0002] For permanent magnet synchronous motors, due to the installation of rotor permanent magnets and the existence of stator slots, their back electromotive force has a certain degree of non-sinusoidality, and the stator current output by the inverter contains harmonics, which causes the electromagnetic torque output by the motor to pulsate, thereby causing motor speed fluctuations, noise and mechanical vibration, thus limiting the application of the motor in high-precision systems and speed regulation systems.

[0003] In the related art, the inverter dead zone compensation method is mainly used to compensate the motor phase current to reduce the fifth and seventh harmonic content to suppress the torque pulsation of the motor. This solution requires a constant load (i.e., the phase current remains unchanged). However, for compressor loads, the load torque changes constantly within a unit operating cycle, and the motor phase current changes constantly, so the dead zone compensation method is difficult to implement. Therefore, how to suppress the motor torque pulsation when the load torque changes is an urgent problem to be solved in this field. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, the first purpose of the present invention is to propose a method for suppressing motor torque pulsation, by compensating the cross-axis current to be compensated according to the electrical angle, rotational speed and current loop modulation frequency of the motor, thereby reducing the pulsation of the cross-axis current and achieving suppression of the motor torque pulsation when the load torque of the motor changes.

[0006] A second object of the present invention is to provide a motor torque pulsation suppression device.

[0007] The third objective of the present invention is to provide a motor controller.

[0008] A fourth objective of the present invention is to provide a readable storage medium.

[0009] To achieve the above-mentioned purpose, the first aspect of the present invention proposes a method for suppressing motor torque pulsation, including: during the operation of the motor, obtaining the electrical angle and actual speed of the motor at the current moment; determining the current speed fluctuation value of the motor according to the actual speed and the currently given speed; determining the current cross-axis current compensation value according to the current speed fluctuation value and the current loop modulation frequency; determining the cross-axis current to be compensated corresponding to the electrical angle at the current moment according to the mapping relationship between the preset key electrical angle and the cross-axis current; compensating the cross-axis current to be compensated using the current cross-axis current compensation value; and driving the motor according to the compensated cross-axis current value.

[0010] According to the motor torque pulsation suppression method of the embodiment of the present invention, first, during the operation of the motor, the electrical angle and actual speed of the motor at the current moment are obtained, and then the current speed fluctuation value of the motor is determined according to the actual speed and the current given speed, and then the current cross-axis current compensation value is determined according to the current speed fluctuation value and the current loop modulation frequency, and the cross-axis current to be compensated corresponding to the electrical angle at the current moment is determined according to the mapping relationship between the preset key electrical angle and the cross-axis current, and finally the cross-axis current to be compensated is compensated using the current cross-axis current compensation value, and the motor is driven according to the compensated cross-axis current value. Therefore, the method can suppress the motor torque pulsation by reducing the pulsation of the cross-axis current when the load torque of the motor changes by compensating the cross-axis current to be compensated according to the electrical angle, speed and current loop modulation frequency of the motor.

[0011] In addition, the motor torque pulsation suppression method according to the above embodiment of the present invention may also have the following additional technical features:

[0012] According to an embodiment of the present invention, determining the current quadrature-axis current compensation value according to the current speed fluctuation value and the current loop modulation frequency includes: Determine the current quadrature axis current compensation value, where Δi q is the current quadrature axis current compensation value, Δn is the speed fluctuation value, f samp is the current loop modulation frequency.

[0013] According to one embodiment of the present invention, before compensating the cross-axis current to be compensated, it also includes: obtaining the electrical frequency of the motor when it is running at the minimum speed; dividing each electrical cycle of the motor into intervals according to the ratio of the current loop modulation frequency to the electrical frequency to determine the key electrical angles contained in each electrical cycle; determining the cross-axis current reference value corresponding to each key electrical angle according to the cross-axis current curve corresponding to the motor under the current load; compensating the cross-axis current to be compensated includes: respectively compensating the first cross-axis current corresponding to the first boundary angle value of the angle interval, and the second cross-axis current corresponding to the second boundary angle value.

[0014] According to one embodiment of the present invention, the step of 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 of intervals a contained in each electrical cycle; Determine the angle range corresponding to each interval; and determine the key electrical angles included in each electrical cycle according to the angle range corresponding to each interval.

[0015] According to an embodiment of the present invention, the first quadrature-axis current corresponding to the first boundary angle value of the angle interval and the second quadrature-axis current corresponding to the second boundary angle value are compensated respectively, including: Compensating the first quadrature-axis current corresponding to the first boundary angle value; The second quadrature-axis current corresponding to the second boundary angle value is compensated, wherein Δi qy is the compensation value of the first quadrature axis current, Δi q is the current quadrature axis current compensation value, θ x is the electrical angle at the current moment, θ y is the first boundary angle value, θ y+1 is the second boundary angle value, Δi qy+1 is the compensation value of the second quadrature-axis current.

[0016] To achieve the above-mentioned purpose, the second aspect of the present invention proposes a motor torque pulsation suppression device, including: an acquisition module, used to acquire the electrical angle and actual speed of the motor at the current moment during the operation of the motor; a determination module, used to determine the current speed fluctuation value of the motor according to the actual speed and the currently given speed; used to determine the current cross-axis current compensation value according to the current speed fluctuation value and the current loop modulation frequency; and used to determine the cross-axis current to be compensated corresponding to the electrical angle at the current moment according to the mapping relationship between the preset key electrical angle and the cross-axis current; a compensation module, used to compensate the cross-axis current to be compensated by using the current cross-axis current supplement value; a driving module, used to drive the motor according to the compensated cross-axis current value after compensating the cross-axis current to be compensated.

[0017] According to the motor torque pulsation suppression device of the embodiment of the present invention, the electrical angle and actual speed of the motor at the current moment are obtained by the acquisition module during the operation of the motor, the current speed fluctuation value of the motor is determined by the determination module according to the actual speed and the current given speed, the current quadrature axis current compensation value is determined according to the current speed fluctuation value and the current loop modulation frequency, and the quadrature axis current to be compensated corresponding to the electrical angle at the current moment is determined according to the mapping relationship between the preset key electrical angle and the quadrature axis current, the quadrature axis current to be compensated is compensated by the compensation module using the current quadrature axis current compensation value; after compensating the quadrature axis current to be compensated, the motor is driven according to the compensated quadrature axis current value by the driving module. Thus, the device can suppress the motor torque pulsation by reducing the pulsation of the quadrature axis current when the load torque of the motor changes by compensating the quadrature axis current to be compensated according to the electrical angle, speed and current loop modulation frequency of the motor.

[0018] In addition, the motor torque pulsation suppression device according to the above embodiment of the present invention may also have the following additional technical features:

[0019] According to one embodiment of the present invention, the acquisition module is also used to: acquire the electrical frequency of the motor when it is running at the minimum speed; divide each electrical cycle of the motor into intervals according to the ratio of the current loop modulation frequency to the electrical frequency to determine the key electrical angles contained in each electrical cycle; determine the cross-axis current reference value corresponding to each key electrical angle according to the cross-axis current curve corresponding to the motor under the current load; the compensation module is specifically used to: respectively compensate for the first cross-axis current corresponding to the first boundary angle value of the angle interval, and the second cross-axis current corresponding to the second boundary angle value.

[0020] In order to achieve the above-mentioned objectives, an embodiment of the third aspect of the present invention proposes a motor controller, comprising: at least one processor; and a memory communicatively connected 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 so that the at least one processor can execute the motor torque pulsation suppression method proposed in the embodiment of the first aspect of the present invention.

[0021] The motor controller of an embodiment of the present invention, when the instructions stored in the memory are executed by at least one processor, can compensate the cross-axis current to be compensated according to the electrical angle, rotational speed and current loop modulation frequency of the motor, thereby reducing the pulsation of the cross-axis current and achieving suppression of the motor torque pulsation when the load torque of the motor changes.

[0022] In order to achieve the above-mentioned purpose, the third aspect of the present invention proposes a readable storage medium on which a motor torque pulsation suppression program is stored. When the program is executed by a processor, the motor torque pulsation suppression method proposed in the first aspect of the present invention is implemented.

[0023] The readable storage medium of an embodiment of the present invention, when the motor torque pulsation suppression program stored thereon is executed by a processor, can compensate the cross-axis current to be compensated according to the electrical angle, rotational speed and current loop modulation frequency of the motor, thereby reducing the pulsation of the cross-axis current and realizing the suppression of the motor torque pulsation when the load torque of the motor changes.

[0024] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0026] Figure 1 is a flow chart of a method for suppressing motor torque pulsation according to an embodiment of the present invention;

[0027] Figure 2 is a flow chart for determining each key angle of a motor and its corresponding quadrature-axis current reference value according to an embodiment of the present invention;

[0028] Figure 3 is a flow chart of dividing each electrical cycle of a motor into intervals according to an example of the present invention;

[0029] Figure 4 4 is a structural block diagram of a motor torque pulsation suppression device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0031] The following describes a method and device for suppressing motor torque pulsation, a motor controller, and a storage medium according to an embodiment of the present invention with reference to the accompanying drawings.

[0032] Figure 1 is a flow chart of a method for suppressing motor torque pulsation according to an embodiment of the present invention.

[0033] like Figure 1 As shown, the method comprises the following steps:

[0034] S101, during the operation of the motor, obtaining the electrical angle and actual speed of the motor at the current moment.

[0035] The motor is a motor in operation whose torque pulsation is to be suppressed, and may be a permanent magnet synchronous motor.

[0036] Specifically, a constant speed command for the motor can be given to drive the motor to run stably with load. The given speed is any speed value within the normal operating speed range of the motor determined according to the motor parameters, and the load can be a compressor load. During the operation of the motor, the current electrical angle and actual speed of the motor can be obtained through the signal collector, and can be stored in the memory for subsequent use.

[0037] It should be understood that the motor can be controlled to operate in a speed closed-loop mode. Specifically, the motor controller can be controlled to operate in a dual closed-loop mode of a speed outer loop and a current inner loop. The input of the speed outer loop is the currently given speed, and the output is the torque value. The current value is calculated based on the torque value, and the current value is the input of the current inner loop. The current value is converted into the motor drive voltage through the current inner loop to drive the motor to operate.

[0038] S102, determining the current speed fluctuation value of the motor according to the actual speed and the currently given speed.

[0039] Specifically, the difference between the actual rotation speed and the currently given rotation speed, that is, the current rotation speed fluctuation value, can be calculated, and the rotation speed fluctuation value can be stored in a memory for subsequent use.

[0040] S103, determining a current quadrature-axis current compensation value according to a current rotational speed fluctuation value and a current loop modulation frequency.

[0041] The current loop modulation frequency may be the frequency of PI (Proportional Integral) regulation performed by the current inner loop, that is, the sampling frequency of the PI regulator.

[0042] It should be noted that the pulsation of the cross-axis current can cause the pulsation of the motor torque, and the pulsation of the motor torque can cause the fluctuation of the motor speed, while the current loop modulation frequency is fixed. Therefore, the current cross-axis current compensation value can be determined based on the current speed fluctuation value and the current loop modulation frequency, and the cross-axis current compensation value can be stored in the memory for subsequent call.

[0043] S104, determining the quadrature-axis current to be compensated corresponding to the electrical angle at the current moment according to a preset mapping relationship between the key electrical angle and the quadrature-axis current.

[0044] The preset key electrical angle may be a plurality of electrical angles in each electrical cycle of the motor.

[0045] It should be noted that when the load of the motor is a compressor load, the load torque of the motor (when the motor is running stably, the load torque is equal to the electromagnetic torque) is positively correlated with the running electrical angle θ, and the control mode of id=0 can be used to control the motor operation, then according to the formula:

[0046] T e =p((L d -L q )i d i q +ψ f i q ) (1)

[0047] The electromagnetic torque T can be obtained e Proportional to the quadrature axis current i q , where p is the number of pole pairs of the motor, L d is the direct-axis inductance, L q is the quadrature-axis inductance, i d is the direct axis current, i q is the quadrature axis current, ψ f is the motor flux. Therefore, the motor's quadrature axis current i q There is a mapping relationship between and the electrical angle θ. Therefore, a preset critical electrical angle can be set, and when the motor is running, the corresponding quadrature axis current can be detected at each preset critical electrical angle of the motor, thereby obtaining the current corresponding to the preset critical electrical angle (θ 0 ,θ 1 ,θ 2 …θ a ) corresponds to the quadrature axis current (i q0 ,i q1 ,i q2 …i qa), where each key electrical angle corresponds to a quadrature axis current, for example, the electrical angle θ 2 Corresponding quadrature axis current i q2 , the motor's quadrature axis current i can be constructed according to the mapping relationship q -Electrical angle θ data table, and the data table can be stored in the memory for subsequent use.

[0048] Therefore, when the current electrical angle of the motor has been obtained in step S101, the actual cross-axis current of the motor at the current electrical angle can be detected first, and then the cross-axis current to be compensated corresponding to the current electrical angle can be determined based on the actual cross-axis current and the mapping relationship.

[0049] S105, using the current quadrature-axis current compensation value to compensate the quadrature-axis current to be compensated.

[0050] Specifically, the calculated current quadrature-axis current compensation value is superimposed on the quadrature-axis current to be compensated, so as to achieve compensation of the quadrature-axis current, thereby reducing the pulsation of the quadrature-axis current.

[0051] S106, driving the motor according to the compensated quadrature-axis current value.

[0052] Specifically, compared with the cross-axis current value before compensation, the pulsation of the cross-axis current value after compensation is greatly reduced. When the motor is driven according to the compensated cross-axis current value, the motor torque pulsation can be suppressed, so that the motor outputs a smooth electromagnetic torque, which greatly reduces the motor speed fluctuation, noise and mechanical vibration.

[0053] Compared with the inverter dead zone compensation method in the related art, the motor torque pulsation suppression method of the embodiment of the present invention obtains a smooth electromagnetic torque by reducing the pulsation of the cross-axis current during the operation of the motor without increasing the hardware cost. Therefore, it is possible to suppress the torque pulsation of the motor when the load torque changes momentarily.

[0054] Therefore, the motor torque pulsation suppression method obtains the actual speed and electrical angle of the motor in real time, and then determines the current compensation value according to the speed fluctuation value and the current loop modulation frequency, and then compensates the quadrature-axis current to be compensated. In this way, the quadrature-axis current can be compensated in real time when the load torque of the motor changes, so as to reduce the pulsation of the quadrature-axis current, thereby achieving the suppression of the motor torque pulsation.

[0055] It should be noted that the above steps S101 to S105 of the embodiment of the present invention may correspond to a program respectively, and each program may be stored in a memory for execution by a processor. When the processor executes the corresponding program in the memory, the above steps S101 to S105 are implemented, thereby realizing the motor torque pulsation suppression method of the embodiment of the present invention. In addition, the above steps S101 to S105 may also be implemented by the following embodiments, which are described in detail below:

[0056] In one embodiment of the present invention, determining the current quadrature-axis current compensation value according to the current speed fluctuation value and the current loop modulation frequency, that is, the above-mentioned step S103, may include:

[0057] According to the formula:

[0058]

[0059] Determine the current quadrature axis current compensation value, where Δi q is the current quadrature axis current compensation value, Δn is the speed fluctuation value, f samp is the current loop modulation frequency.

[0060] In one embodiment of the present invention, Figure 2 As shown, before compensating the quadrature-axis current to be compensated in the above step S105, the following steps are also included:

[0061] S201, obtaining the electrical frequency of the motor when it is running at the minimum speed.

[0062] Specifically, according to the formula:

[0063]

[0064] Calculate the minimum speed n of the motor min Electrical frequency during operation f min , where p is the number of pole pairs of the motor.

[0065] S202, 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 included in each electrical cycle.

[0066] Among them, each electrical cycle of the motor refers to the time for each pair of rotating magnetic poles of the motor to rotate one circle, which is 360°. That is to say, each pair of rotating magnetic poles of the motor corresponds to an electrical cycle of 360°.

[0067] Specifically, the current loop modulation frequency f can be calculated first samp With electrical frequency f minThen, according to the ratio, a complete electrical cycle of 360° corresponding to each pair of rotating magnetic poles of the motor is divided into a intervals, where a≥1 and a is an integer, so that each electrical cycle contains a+1 key electrical angles, and each key electrical angle can be stored in a memory to wait for the subsequent determination of the quadrature-axis current reference value corresponding to each key electrical angle.

[0068] S203, determining the quadrature axis current reference values ​​corresponding to each key electrical angle according to the quadrature axis current curve corresponding to the motor under the current load, wherein the quadrature axis current curve refers to the actual quadrature axis current curve tested when the motor is running stably with load.

[0069] It should be noted that for a motor that drives a compressor-type load, when it runs stably in the speed closed-loop control mode, the motor's cross-axis current changes with the load torque, and the load torque changes with the motor's electrical angle. Therefore, it can be obtained that the motor's load torque changes with the electrical angle.

[0070] Specifically, when the motor is running, the current value obtained according to the torque value output by the speed outer loop can be detected, and the corresponding quadrature-axis current curve under the current load can be drawn according to the current value. Then, the quadrature-axis current reference values ​​corresponding to each key electrical angle can be determined according to the quadrature-axis current curve.

[0071] It is understandable that each quadrature-axis current reference value may have multiple quadrature-axis current values ​​to be compensated. After each quadrature-axis current reference value is determined, each quadrature-axis current reference value may be compared with the quadrature-axis current i obtained in step S104. q -Electrical angle θ The quadrature-axis currents corresponding to the key electrical angles in the data table are compared. If the quadrature-axis current reference value is different from the corresponding quadrature-axis current, it means that the quadrature-axis current reference value pulsates and is the quadrature-axis current to be compensated.

[0072] Correspondingly, compensating the quadrature-axis current to be compensated in the above step S105 includes: respectively compensating the first quadrature-axis current corresponding to the first boundary angle value of the angle interval and the second quadrature-axis current corresponding to the second boundary angle value.

[0073] Specifically, the current electrical angle θ can be obtained first x The angle range (θ y ,θ y+1 ), where θ y is the first boundary angle value, θ y+1 is the second boundary angle value, and then the current quadrature axis current compensation value Δi is used q For the first boundary angle value θ y The corresponding first quadrature-axis current i qrefy , and the second boundary angle value θ y+1The corresponding second quadrature-axis current i qrefy+1 Compensate separately.

[0074] Furthermore, if Figure 3 As shown, each electrical cycle of the motor is divided into intervals according to the ratio of the current loop modulation frequency to the electrical frequency, that is, the above step S202, which may include the following steps:

[0075] 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.

[0076] Specifically, according to the formula:

[0077]

[0078] Calculate the number of intervals a contained in each electrical cycle of the motor, where f samp is the current loop modulation frequency, a is an integer.

[0079] S302, according to the formula:

[0080]

[0081] Determine the angle range d1 and d2 corresponding to each interval, where d is the electrical angle value corresponding to each interval.

[0082] S303: Determine key electrical angles included in each electrical cycle according to the angle range corresponding to each interval.

[0083] For example, if a=4 is calculated, that is, each electrical cycle of the motor is divided into 4 intervals, the angle ranges d1 and d2 corresponding to each interval are 0°~90°, 90°~180°, 180°~270°, and 270°~360° respectively, and the electrical angle of each interval is 90°. It can be seen that the key electrical angles contained in each electrical cycle are 0°, 90°, 270° and 360°.

[0084] In one example, compensating for a first quadrature-axis current corresponding to a first boundary angle value of the angle interval and a second quadrature-axis current corresponding to a second boundary angle value respectively includes:

[0085] According to the formula:

[0086]

[0087] The first quadrature-axis current corresponding to the first boundary angle value is compensated according to the formula:

[0088]

[0089] The second quadrature axis current corresponding to the second boundary angle value is compensated, where Δi qy is the compensation value of the first quadrature axis current, Δi q is the current quadrature axis current compensation value, θ x is the electrical angle at the current moment, θ y is the first boundary angle value, θ y+1 is the second boundary angle value, Δi qy+1 is the compensation value of the second quadrature-axis current, and g is the proportional coefficient.

[0090] Specifically, firstly, the compensation value Δi of the first quadrature-axis current value is calculated according to formula (5) and formula (6) respectively: qy and the compensation value Δi of the second quadrature-axis current value qy+1 , and then the compensation value Δi of the first quadrature-axis current value is qy and the compensation value Δi of the second quadrature-axis current value qy+1 respectively superimposed on the first quadrature axis current i qrefy and the second quadrature axis current i qrefy+1 That is, the current quadrature axis current compensation value Δi q Superimpose them proportionally to the first boundary angle value θ y , the second boundary angle value θ y+1 The first quadrature-axis current i qrefy , the second quadrature axis current i qrefy+1 This can reduce the cross-axis current pulsation and obtain a stable electromagnetic torque effect.

[0091] In an example of the present invention, after compensating the quadrature-axis current to be compensated, the method further includes: driving the motor according to the compensated quadrature-axis current value.

[0092] Specifically, after compensating the cross-axis current to be compensated, the compensated cross-axis current value can be input into the current inner loop, and the compensated cross-axis current value is converted into the driving voltage of the motor through the current inner loop to drive the motor to operate. At this time, the electromagnetic torque output by the motor no longer pulsates.

[0093] In summary, the method compensates the quadrature-axis current to be compensated according to the electrical angle, rotational speed and current loop modulation frequency of the motor, thereby reducing the pulsation of the quadrature-axis current and suppressing the torque pulsation of the motor when the load torque of the motor changes.

[0094] In order to implement the above embodiment, the present invention also proposes a motor torque pulsation suppression device. Figure 4 4 is a structural block diagram of a motor torque pulsation suppression device according to an embodiment of the present invention.

[0095] like Figure 4As shown, the motor torque pulsation suppression device 10 includes an acquisition module 11 , a determination module 12 , a compensation module 13 and a drive module 14 .

[0096] Among them, the acquisition module 11 is used to obtain the electrical angle and actual speed of the motor at the current moment during the operation of the motor; the determination module 12 is used to determine the current speed fluctuation value of the motor according to the actual speed and the currently given speed; it is used to determine the current cross-axis current compensation value according to the current speed fluctuation value and the current loop modulation frequency; and it is used to determine the cross-axis current to be compensated corresponding to the electrical angle at the current moment according to the mapping relationship between the preset key electrical angle and the cross-axis current; the compensation module 13 is used to compensate the cross-axis current to be compensated by using the current cross-axis current supplement value; the driving module 14 is used to drive the motor according to the compensated cross-axis current value after compensating the cross-axis current to be compensated.

[0097] Specifically, in actual applications, first, the electrical angle and actual speed of the motor at the current moment are acquired during the operation of the motor through the acquisition module 11; then, the current speed fluctuation value of the motor is determined according to the actual speed and the currently given speed through the determination module 12; the current cross-axis current compensation value is determined according to the current speed fluctuation value and the current loop modulation frequency; and, according to the mapping relationship between the preset key electrical angle and the cross-axis current, the cross-axis current to be compensated corresponding to the electrical angle at the current moment is determined; finally, the compensation module 13 uses the current cross-axis current supplement value to compensate the cross-axis current to be compensated; after the cross-axis current to be compensated is compensated, the motor is driven according to the compensated cross-axis current value through the drive module 14.

[0098] In one embodiment of the present invention, the acquisition module 12 can also be used to: obtain the electrical frequency of the motor when it is running at the minimum speed; divide each electrical cycle of the motor into intervals according to the ratio of the current loop modulation frequency to the electrical frequency to determine the key electrical angles contained in each electrical cycle; determine the cross-axis current reference value corresponding to each key electrical angle according to the cross-axis current curve corresponding to the motor under the current load; accordingly, the compensation module 13 can be specifically used to: respectively compensate for the first cross-axis current corresponding to the first boundary angle value of the angle interval, and the second cross-axis current corresponding to the second boundary angle value.

[0099] It should be noted that the above explanation of the motor torque pulsation suppression method embodiment is also applicable to the motor torque pulsation suppression device of this embodiment, and will not be repeated here.

[0100] The motor torque pulsation suppression device of the embodiment of the present invention compensates the quadrature-axis current to be compensated according to the electrical angle, rotational speed and current loop modulation frequency of the motor, thereby reducing the pulsation of the quadrature-axis current and suppressing the motor torque pulsation when the load torque of the motor changes.

[0101] Furthermore, the present invention also proposes a motor controller, comprising: at least one processor and a memory communicatively connected to the at least one processor.

[0102] Among them, the memory stores instructions that can be executed by at least one processor, and the instructions are executed by at least one processor so that the at least one processor can execute the motor torque pulsation suppression method proposed in the embodiment of the first aspect of the present invention.

[0103] When the instructions stored in the memory of the motor controller are executed by at least one processor, the motor controller can compensate the cross-axis current to be compensated according to the electrical angle, rotational speed and current loop modulation frequency of the motor, thereby reducing the pulsation of the cross-axis current and suppressing the motor torque pulsation when the load torque of the motor changes.

[0104] In order to implement the above embodiment, the present invention also proposes a readable storage medium on which a motor torque pulsation suppression program is stored. When the program is executed by a processor, the motor torque pulsation suppression method proposed in the embodiment of the first aspect of the present invention is implemented.

[0105] When the motor torque pulsation suppression program stored on the readable storage medium is executed by a processor, the cross-axis current to be compensated can be compensated according to the electrical angle, rotational speed and current loop modulation frequency of the motor, thereby reducing the pulsation of the cross-axis current and achieving the suppression of the motor torque pulsation when the load torque of the motor changes.

[0106] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0107] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0108] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present invention belong.

[0109] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute the instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0110] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0111] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0112] In addition, each functional unit in each embodiment of the present invention may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0113] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for suppressing motor torque pulsation, characterized in that: include: During the operation of the motor, obtain the current electrical angle and actual speed of the motor; Determine the current speed fluctuation value of the motor according to the actual speed and the current given speed; Determining a current quadrature-axis current compensation value according to the current speed fluctuation value and the current loop modulation frequency; Determine the quadrature-axis current to be compensated corresponding to the electrical angle at the current moment according to a mapping relationship between a preset 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; driving the motor according to the compensated quadrature-axis current value; Before compensating the quadrature-axis current to be compensated, the method further includes: Obtaining the electrical frequency of the motor when it is running at the minimum speed; According to the ratio of the current loop modulation frequency to the electrical frequency, each electrical cycle of the motor is divided into intervals to determine each key electrical angle contained in each electrical cycle; Determining the quadrature-axis current reference values ​​corresponding to the key electrical angles according to the quadrature-axis current curve corresponding to the motor under the current load; The compensating the quadrature-axis current to be compensated comprises: Compensating respectively a first quadrature-axis current corresponding to a first boundary angle value of the angle interval and a second quadrature-axis current corresponding to a second boundary angle value; The first quadrature-axis current corresponding to the first boundary angle value of the angle interval and the second quadrature-axis current corresponding to the second boundary angle value are compensated respectively, including: according to , compensating a first quadrature-axis current corresponding to the first boundary angle value; according to , compensating the second quadrature-axis current corresponding to the second boundary angle value, Among them, Δi qy is the compensation value of the first quadrature-axis current, Δi q is the current quadrature axis current compensation value, θ x is the electrical angle at the current moment, θ y is the first boundary angle value, θ y+1 is the second boundary angle value, Δi qy+1 is the compensation value of the second quadrature-axis current, and g is the proportional coefficient.

2. The method according to claim 1, characterized in that The determining of the current quadrature-axis current compensation value according to the current speed fluctuation value and the current loop modulation frequency includes: according to , determine the current quadrature-axis current compensation value, Among them, Δi q is the current quadrature axis current compensation value, Δn is the speed fluctuation value, f samp is the current loop modulation frequency.

3. The method according to claim 1, characterized in that The step of 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 of intervals a contained in each electrical cycle; according to , determine the angle range corresponding to each interval; According to the angle range corresponding to each interval, each key electrical angle included in each electrical cycle is determined.

4. A motor torque pulsation suppression device, characterized in that: include: The acquisition module is used to obtain the electrical angle and actual speed of the motor at the current moment during the operation of the motor; A determination module, used to determine the current speed fluctuation value of the motor according to the actual speed and the current given speed; used to determine the current quadrature-axis current compensation value according to the current speed fluctuation value and the current loop modulation frequency; And, for determining the quadrature-axis current to be compensated corresponding to the electrical angle at the current moment according to a mapping relationship between a preset key electrical angle and the quadrature-axis current; A compensation module, used to compensate the quadrature-axis current to be compensated by using the current quadrature-axis current supplement value; A driving module, configured to drive the motor according to a value of the compensated quadrature-axis current after compensating the quadrature-axis current to be compensated; The acquisition module is further used for: Obtaining the electrical frequency of the motor when it is running at the minimum speed; According to the ratio of the current loop modulation frequency to the electrical frequency, each electrical cycle of the motor is divided into intervals to determine each key electrical angle contained in each electrical cycle; Determining the quadrature-axis current reference values ​​corresponding to the key electrical angles according to the quadrature-axis current curve corresponding to the motor under the current load; The compensation module is specifically used for: Compensating respectively a first quadrature-axis current corresponding to a first boundary angle value of the angle interval and a second quadrature-axis current corresponding to a second boundary angle value; The first quadrature-axis current corresponding to the first boundary angle value of the angle interval and the second quadrature-axis current corresponding to the second boundary angle value are compensated respectively, including: according to , compensating a first quadrature-axis current corresponding to the first boundary angle value; according to , compensating the second quadrature-axis current corresponding to the second boundary angle value, Among them, Δi qy is the compensation value of the first quadrature-axis current, Δi q is the current quadrature axis current compensation value, θ x is the electrical angle at the current moment, θ y is the first boundary angle value, θ y+1 is the second boundary angle value, Δi qy+1 is the compensation value of the second quadrature-axis current, and g is the proportional coefficient.

5. A motor controller, characterized in that: include: at least one processor; as well as 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 so that the at least one processor can execute the motor torque pulsation suppression method as described in any one of claims 1-3.

6. A readable storage medium, characterized in that: A motor torque pulsation suppression program is stored thereon, and when the program is executed by a processor, a motor torque pulsation suppression method as described in any one of claims 1-3 is implemented.

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