阅读说明：本技术 一种电机的控制方法及控制系统 (Control method and control system of motor ) 是由 张彦超 曲道奎 宋吉来 胡俊 李颖 王羽瑾 于 2018-12-25 设计创作，主要内容包括：本申请涉及电机控制技术领域,具体公开一种电机的控制方法及控制系统,包括：电机励磁之后,检测并获取所述电机的直轴电感和交轴电感；根据电流环传递函数建立所述电机的电流环传递函数模型；根据预设公式计算所述电机的定子电感；根据所述定子电感和所述电流环传递函数模型确定所述电机输出的PWM频率；根据所述频率对所述电机进行矢量控制。这一过程中可根据电感值的不同对PWM输出频率进行动态的调整,以对电机电流纹波进行抑制,达到提高控制电机的效果及降低电机电流纹波的目的。(The application relates to the technical field of motor control, and particularly discloses a control method and a control system of a motor, which comprise the following steps: after the motor is excited, detecting and acquiring direct-axis inductance and quadrature-axis inductance of the motor; establishing a current loop transfer function model of the motor according to a current loop transfer function; calculating the stator inductance of the motor according to a preset formula; determining the PWM frequency output by the motor according to the stator inductance and the current loop transfer function model; and carrying out vector control on the motor according to the frequency. In the process, the PWM output frequency can be dynamically adjusted according to different inductance values so as to inhibit the motor current ripple and achieve the purposes of improving the motor control effect and reducing the motor current ripple.)

1. A method of controlling a motor, comprising:

after the motor is excited, detecting and acquiring direct-axis inductance and quadrature-axis inductance of the motor;

establishing a current loop transfer function model of the motor according to a current loop transfer function;

calculating the stator inductance of the motor according to a preset formula;

determining the PWM frequency output by the motor according to the stator inductance and the current loop transfer function model;

and carrying out vector control on the motor according to the frequency.

2. The method of controlling a motor according to claim 1, wherein said detecting and obtaining a direct-axis inductance of the motor comprises:

applying a fixed space vector voltage to the motor through the inverter;

when the current of the motor reaches a stable state under the space vector voltage, recording the time t when the current reaches the stable state_d；

According to a permanent magnet synchronous motor voltage equation and the preset current and time t_dCalculating the direct axis inductance L of the motor_d。

3. The method for controlling the motor according to claim 1, wherein the detecting and acquiring the quadrature axis inductance of the motor comprises:

applying a fixed space vector voltage to the motor through the inverter;

when the current of the motor reaches a stable state under the space vector voltage, recording the time t when the current reaches the stable state_q；

According to the alternating current inductance and the space vector voltage and the preset current and time t_dCalculating quadrature axis inductance L of the motor_q。

4. The method of controlling an electric machine of claim 1, wherein said determining a PWM frequency of said electric machine output based on said stator inductance and said current loop transfer function model comprises:

acquiring phase potential when the motor runs;

calculating a PWM frequency of the motor output from the phase potential, the stator inductance, and the current loop transfer function model.

5. The method for controlling the motor according to any one of claims 1 to 4, further comprising, after the detecting and acquiring the direct-axis inductance and quadrature-axis inductance of the motor:

and judging whether the motor is a preset type motor or not according to the direct axis inductance and the quadrature axis inductance.

6. A control system for an electric machine, the control system comprising:

the inductance acquisition module is used for detecting and acquiring direct axis inductance and quadrature axis inductance of the motor after the motor is excited;

the model establishing module is used for establishing a current loop transfer function model of the motor according to a current loop transfer function;

the calculation module is used for calculating the stator inductance of the motor according to a preset formula and determining the PWM frequency output by the motor according to the stator inductance and the current loop transfer function model;

and the control module is used for carrying out vector control on the motor according to the frequency.

7. The control system of an electric machine according to claim 6, wherein the inductance obtaining module is specifically configured to:

applying a fixed space vector voltage to the motor through the inverter;

when the current of the motor reaches a stable state under the space vector voltage, recording the time t when the current reaches the stable state_d；

According to a permanent magnet synchronous motor voltage equation and the preset current and time t_dCalculating the direct axis inductance L of the motor_d。

8. The control system of an electric machine of claim 6, wherein the inductance acquisition module is further configured to:

applying a fixed space vector voltage to the motor through the inverter;

when the current of the motor reaches a stable state under the space vector voltage, recording the time t when the current reaches the stable state_q；

According to the alternating current inductance and the space vector voltage and the preset current and time t_dCalculating quadrature axis inductance L of the motor_q。

9. The control system of an electric machine of claim 6, wherein the calculation module is specifically configured to:

acquiring phase potential when the motor runs;

calculating a PWM frequency of the motor output from the phase potential, the stator inductance, and the current loop transfer function model.

10. The control system of an electric motor according to any one of claims 6 to 9, further comprising:

and the judging module is used for judging whether the motor is a preset type motor according to the direct axis inductance and the quadrature axis inductance.

Technical Field

The present disclosure relates to the field of motor control technologies, and in particular, to a control method and a control system for a motor.

Background

In the last year, under the development of technologies such as unmanned vehicles, unmanned planes, cooperative robots, service robots, and the like, the application range of the servo driving technology is becoming wider and wider, and in particular, the application field 0 of the low-voltage servo motor is becoming wider. Different requirements are also placed on the characteristics of the motor in different fields, for example, the motor installed in a cooperative robot, an unmanned aerial vehicle and the like generally requires small volume, high power density, low speed, high torque or high rotating speed and other performances. Under the application requirement, the coreless motor is more and more widely applied by the characteristics of high power density, high rotating speed and low inertia.

The existing low-voltage servo motor, especially the coreless motor driving technology with smaller inductance, has PWM frequency of 10KHZ-20KHZ, and some can reach 40KHZ, because the driver lacks the automatic identification function to the motor inductance motor, the driver can only run with the fixed parameters set by the user, because the coreless motor is much smaller than the brushless DC motor inductance motor of the permanent magnet rotor, the control coreless motor with the same PWM frequency can cause too large motor current ripple, and the motor load capacity is not enough and the service life of the motor is influenced directly.

Disclosure of Invention

In view of this, embodiments of the present application provide a control method and a control system for a motor, so as to solve the problems in the prior art that when a PWM frequency is used to control a coreless motor, a ripple of a motor current is too large, which causes a load capacity of the motor to be insufficient and affects a life of the motor.

A first aspect of an embodiment of the present application provides a method for controlling a motor, where the method for controlling a motor includes:

after the motor is excited, detecting and acquiring direct-axis inductance and quadrature-axis inductance of the motor;

establishing a current loop transfer function model of the motor according to a current loop transfer function;

calculating the stator inductance of the motor according to a preset formula;

determining the PWM frequency output by the motor according to the stator inductance and the current loop transfer function model;

and carrying out vector control on the motor according to the frequency.

Optionally, the detecting and acquiring the direct-axis inductance of the motor includes:

applying a fixed space vector voltage to the motor through the inverter;

when the current of the motor reaches a stable state under the space vector voltage, recording the time t when the current reaches the stable state_d；

According to a permanent magnet synchronous motor voltage equation and the preset current and time t_dCalculating the direct axis inductance L of the motor_d。

Optionally, the detecting and acquiring quadrature axis inductance of the motor includes:

applying a fixed space vector voltage to the motor through the inverter;

when the current of the motor reaches a stable state under the space vector voltage, recording the time t when the current reaches the stable state_q；

According to the alternating current inductance and the space vector voltage and the preset current and time t_dCalculating quadrature axis inductance L of the motor_q。

Optionally, the determining a PWM frequency of the motor output according to the stator inductance and the current loop transfer function model includes:

acquiring phase potential when the motor runs;

calculating a PWM frequency of the motor output from the phase potential, the stator inductance, and the current loop transfer function model.

Optionally, after the detecting and acquiring the direct axis inductance and the quadrature axis inductance of the motor, the method further includes:

and judging whether the motor is a preset type motor or not according to the direct axis inductance and the quadrature axis inductance.

A second aspect of embodiments of the present application provides a control system of a motor, including:

and the inductance acquisition module is used for detecting and acquiring the direct axis inductance and the quadrature axis inductance of the motor after the motor is excited.

And the model establishing module is used for establishing a current loop transfer function model of the motor according to the current loop transfer function.

And the calculation module is used for calculating the stator inductance of the motor according to a preset formula and determining the PWM frequency output by the motor according to the stator inductance and the current loop transfer function model.

And the control module is used for carrying out vector control on the motor according to the frequency.

Optionally, the inductance obtaining module is specifically configured to:

applying a fixed space vector voltage to the motor through the inverter;

when the current of the motor reaches a stable state under the space vector voltage, recording the time t when the current reaches the stable state_d；

According to a permanent magnet synchronous motor voltage equation and the preset current and time t_dCalculating the direct axis inductance L of the motor_d。

Optionally, the inductance obtaining module is further configured to:

applying a fixed space vector voltage to the motor through the inverter;

when the current of the motor reaches a stable state under the space vector voltage, recording the time t when the current reaches the stable state_q；

According to the alternating current inductance and the space vector voltage and the preset current and time t_dCalculating quadrature axis inductance L of the motor_q。

Optionally, the calculation module is specifically configured to:

acquiring phase potential when the motor runs;

calculating a PWM frequency of the motor output from the phase potential, the stator inductance, and the current loop transfer function model.

Optionally, the control system of the motor further comprises:

and the judging module is used for judging whether the motor is a preset type motor according to the direct axis inductance and the quadrature axis inductance.

In the embodiment provided by the application, after the motor is excited, the direct axis inductance and the quadrature axis inductance of the motor are obtained, a current loop transfer function model of the motor is established, then the stator inductance of the motor is calculated according to a preset formula, and the PWM frequency output by the motor is determined according to the stator inductance and the established current loop transfer function, so that the purpose of vector control on the motor according to the PWM frequency is achieved. In the process, the PWM output frequency can be dynamically adjusted according to different inductance values so as to inhibit the motor current ripple and achieve the purposes of improving the motor control effect and reducing the motor current ripple.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly described below.

Fig. 1 is a schematic implementation flow chart of a control method of a motor according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a current loop transfer function model created in an embodiment provided herein;

FIG. 3 is a schematic diagram of the direct axis current and quadrature axis current over time provided by an embodiment of the present application;

fig. 4 is a schematic structural diagram of a control system of a motor according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the application and do not constitute a limitation on the application.

In the embodiment provided by the application, after the motor is excited, the direct axis inductance and the quadrature axis inductance of the motor are obtained, a current loop transfer function model of the motor is established, then the stator inductance of the motor is calculated according to a preset formula, and the PWM frequency output by the motor is determined according to the stator inductance and the established current loop transfer function, so that the purpose of vector control on the motor according to the PWM frequency is achieved.

In order to explain the technical solution described in the present application, the following description will be given by way of specific examples.