阅读说明：本技术 直流无刷电机的控制方法、装置和系统 (Control method, device and system of direct current brushless motor ) 是由 胡勇 于 2020-06-01 设计创作，主要内容包括：本发明提供了一种直流无刷电机的控制方法、装置和系统,通过控制设备采集调制电路的输入电流和直流无刷电机的三相电压；根据输入电流和三相电压,确定直流无刷电机的当前转速；根据当前转速和预设转速,通过控制设备,调整直流受控源的输出电压,以基于输出电压,控制直流无刷电机的转速。该方式中,通过控制设备直接调整直流受控源的输出电压,以控制直流无刷电机的转速,提高了直流无刷电机低速运行的调速性能,降低了系统对外的电磁骚扰。(The invention provides a control method, a device and a system of a direct current brushless motor, which are characterized in that input current of a modulation circuit and three-phase voltage of the direct current brushless motor are collected through control equipment; determining the current rotating speed of the direct current brushless motor according to the input current and the three-phase voltage; and adjusting the output voltage of the direct current controlled source through the control equipment according to the current rotating speed and the preset rotating speed so as to control the rotating speed of the direct current brushless motor based on the output voltage. In the mode, the output voltage of the direct current controlled source is directly adjusted through the control equipment to control the rotating speed of the direct current brushless motor, so that the speed regulation performance of the direct current brushless motor in low-speed operation is improved, and the electromagnetic disturbance of the system to the outside is reduced.)

1. A control method of a brushless DC motor is characterized in that the method is applied to a control device; the control equipment is respectively connected with the modulation circuit and the direct current controlled source; the modulation circuit is respectively connected with the direct current controlled source and the direct current brushless motor; the method comprises the following steps:

collecting input current of the modulation circuit and three-phase voltage of the direct current brushless motor;

determining the current rotating speed of the direct current brushless motor according to the input current and the three-phase voltage;

and adjusting the output voltage of the direct current controlled source according to the current rotating speed and a preset rotating speed so as to control the rotating speed of the direct current brushless motor based on the output voltage.

2. The method of claim 1, wherein the step of determining a present speed of the dc brushless motor based on the input current and the three-phase voltages comprises:

and determining the current rotating speed of the direct current brushless motor through a preset control algorithm according to the input current and the three-phase voltage.

3. The method of claim 1, wherein the control device comprises a power control module;

adjusting the output voltage of the direct current controlled source according to the current rotating speed and the preset rotating speed, wherein the step comprises the following steps:

comparing the current rotating speed with the preset rotating speed to obtain a rotating speed regulating quantity;

and adjusting the output voltage of the direct current controlled source by utilizing a power supply voltage adjusting signal output by the power supply control module according to the rotating speed adjusting quantity so as to enable the current rotating speed of the direct current brushless motor to meet the preset rotating speed.

4. The method of claim 1, wherein the pulse width modulated waveform output by the modulation circuit has a duty cycle of one.

5. The method of claim 1, further comprising:

determining the relative voltage of the three-phase voltage according to the three-phase voltage;

determining the current phase of the brushless direct current motor according to the relative voltage of the three-phase voltage;

and controlling the phase change of the direct current brushless motor according to the current phase.

6. The method of claim 1, wherein the input current is the same as a current of the dc brushless motor.

7. A control device of a brushless DC motor is characterized in that the device is arranged on a control device; the control equipment is respectively connected with the modulation circuit and the direct current controlled source; the modulation circuit is respectively connected with the direct current controlled source and the direct current brushless motor; the device comprises:

the acquisition module is used for acquiring the input current of the modulation circuit and the three-phase voltage of the direct current brushless motor;

the determining module is used for determining the current rotating speed of the direct current brushless motor according to the input current and the three-phase voltage;

and the control module is used for adjusting the output voltage of the direct current controlled source according to the current rotating speed and a preset rotating speed so as to control the rotating speed of the direct current brushless motor based on the output voltage.

8. The apparatus of claim 7, wherein the control device comprises a power control module;

the control module further comprises:

the comparison unit is used for comparing the current rotating speed with the preset rotating speed to obtain a rotating speed regulating quantity;

and the adjusting unit is used for adjusting the output voltage of the direct current controlled source by utilizing a power supply voltage adjusting signal output by the power supply control module according to the rotating speed adjusting quantity so as to enable the current rotating speed of the direct current brushless motor to meet the preset rotating speed.

9. The apparatus of claim 7, wherein the pulse width modulated waveform output by the modulation circuit has a duty cycle of one.

10. A control system, characterized in that the control system comprises: the control device, the direct current controlled source, the modulation circuit and the direct current brushless motor;

the control equipment is respectively connected with the direct current controlled source and the modulation circuit; the modulation circuit is respectively connected with the direct current controlled source and the direct current brushless motor;

a control apparatus of the brushless dc motor according to claim 9 is mounted on the control device;

the modulation circuit is used for controlling the rotating speed and the phase change of the direct current brushless motor.

Technical Field

The invention relates to the technical field of motor control, in particular to a control method, a control device and a control system of a direct-current brushless motor.

Background

Controlling a Brushless Direct Current Motor (BLDCM), mainly performing phase change and speed regulation on the Motor; in a conventional speed regulation mode, control equipment is usually adopted to collect associated voltage and current in a pulse width modulation circuit, determine the current rotating speed according to the associated voltage and current, and control the rotating speed of a direct current brushless motor by adjusting the duty ratio of a pulse width modulation waveform. However, the output voltage of the dc voltage stabilizing source is relatively fixed, the collected three-phase voltage is the dc bus voltage, the voltage frequency is the switching frequency of the pulse width modulation circuit, filtering and algorithm analysis need to be performed on the collected voltage of the pulse width modulation waveform, and a certain error exists in the motor phase obtained in this way.

Disclosure of Invention

In view of the above, the present invention provides a method, an apparatus and a system for controlling a dc brushless motor to improve the low speed control performance of the dc brushless motor.

In a first aspect, embodiments of the present invention provide a method for controlling a dc brushless motor, where the method is applied to a control device; the control equipment is respectively connected with the modulation circuit and the direct current controlled source; the modulation circuit is respectively connected with the modulation circuit and the direct current brushless motor; the method comprises the following steps: acquiring input current of a modulation circuit and three-phase voltage of a direct current brushless motor; determining the current rotating speed of the direct current brushless motor according to the input current and the three-phase voltage; and adjusting the output voltage of the direct current controlled source according to the current rotating speed and the preset rotating speed so as to control the rotating speed of the direct current brushless motor based on the output voltage.

Further, the step of determining the current rotation speed of the dc brushless motor according to the input current and the three-phase voltage includes: and determining the current rotating speed of the direct current brushless motor according to the input current and the three-phase voltage through a preset control algorithm.

Further, the control device comprises a power supply control module; the step of adjusting the output voltage of the direct current controlled source according to the current rotating speed and the preset rotating speed comprises the following steps: comparing the current rotating speed with a preset rotating speed to obtain a rotating speed regulating quantity; and adjusting the output voltage of the direct current controlled source by utilizing a power supply voltage adjusting signal output by the power supply control module according to the rotating speed adjusting quantity so as to enable the current rotating speed of the direct current brushless motor to meet the preset rotating speed.

Further, the duty ratio of the pulse width modulation waveform output by the modulation circuit is one.

Further, the method further comprises: determining the relative voltage of the three-phase voltage according to the three-phase voltage; determining the current phase of the direct current brushless motor according to the relative voltage of the three-phase voltage; and controlling the phase change of the direct current brushless motor according to the current phase.

Further, the input current is the same as the current of the dc brushless motor.

In a second aspect, an embodiment of the present invention provides a control apparatus for a dc brushless motor, the apparatus being provided in a control device; the control equipment is respectively connected with the modulation circuit and the direct current controlled source; the modulation circuit is connected with the direct current controlled source and the direct current brushless motor; the device comprises: the acquisition module is used for acquiring the input current of the modulation circuit and the three-phase voltage of the DC brushless motor; the determining module is used for determining the current rotating speed of the direct current brushless motor according to the input current and the three-phase voltage; and the control module is used for adjusting the output voltage of the direct current controlled source according to the current rotating speed and the preset rotating speed so as to control the rotating speed of the direct current brushless motor based on the output voltage.

Further, the control device comprises a power supply control module; the control module further comprises: the comparison unit is used for comparing the current rotating speed with a preset rotating speed to obtain a rotating speed regulating quantity; and the adjusting unit is used for adjusting the output voltage of the direct current controlled source by utilizing the power supply voltage adjusting signal output by the power supply control module according to the rotating speed adjusting quantity so as to enable the current rotating speed of the direct current brushless motor to meet the preset rotating speed.

Further, the duty ratio of the pulse width modulation waveform output by the modulation circuit is one.

In a third aspect, an embodiment of the present invention provides a control system, where the control system includes: the control device, the direct current controlled source, the modulation circuit and the direct current brushless motor; the control equipment is respectively connected with the direct current controlled source and the modulation circuit; the modulation circuit is respectively connected with the direct current controlled source and the direct current brushless motor; the control device is provided with a control device of the DC brushless motor of the second aspect; the modulation circuit is used for controlling the rotating speed and the phase change of the direct current brushless motor.

The embodiment of the invention has the following beneficial effects:

the invention provides a control method, a device and a system of a direct current brushless motor, which are characterized in that input current of a modulation circuit and three-phase voltage of the direct current brushless motor are collected through control equipment; determining the current rotating speed of the direct current brushless motor according to the input current and the three-phase voltage; and adjusting the output voltage of the direct current controlled source according to the current rotating speed and the preset rotating speed so as to control the rotating speed of the direct current brushless motor based on the output voltage. In the mode, the output voltage of the direct current controlled source is directly adjusted through the control equipment to control the rotating speed of the direct current brushless motor, so that the speed regulation performance of the direct current brushless motor in low-speed operation is improved, and the electromagnetic disturbance of the system to the outside is reduced.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a circuit diagram illustrating a control method of a conventional dc brushless motor according to an embodiment of the present invention;

fig. 2 is a flowchart of a method for controlling a dc brushless motor according to an embodiment of the present invention;

fig. 3 is a circuit diagram of a method for controlling a dc brushless motor according to an embodiment of the present invention;

fig. 4 is a flowchart of another dc brushless motor control method according to an embodiment of the present invention;

FIG. 5 is a diagram illustrating a conventional voltage signal according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of a voltage signal according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a control device of a dc brushless motor according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of a control system according to an embodiment of the present invention.

Detailed Description

To make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

At present, a conventional control method of a dc brushless motor, as shown in fig. 1, generally includes a regulated dc power supply, a six-transistor three-phase half-bridge circuit, and a control device; the output voltage (A, B, C), the direct-current voltage-stabilizing source voltage (vdc) and the direct current (idc) of the three-phase bridge arm are obtained by controlling A, B, C, vdc + and idc + relative idc-in a sampling circuit of equipment, and the current phase and the current rotating speed of the direct-current brushless motor are judged through a control algorithm; determining bridge arms for switching according to the current phase information (the direct current brushless motor only works in two phases at each moment, namely only works in two corresponding bridge arms at each moment); and performing feedback control on the current rotating speed and the set rotating speed to obtain an adjustment quantity, and adjusting the duty ratio of switching control pulse width modulation waveforms of IG 1-IG 6 switching tubes in the six-tube three-phase half-bridge circuit according to the adjustment quantity so as to achieve the purpose of speed regulation. When the motor is started or runs at low speed, the duty ratio of the pulse width modulation waveform is small, so that the motor cannot work stably, and the low-speed performance is poor. Based on this, the present invention provides a method, an apparatus, and a system for controlling a dc brushless motor, and the technique can be applied to a control device of a dc brushless motor. For the convenience of understanding the present embodiment, a detailed description will be given to a control method of a dc brushless motor disclosed in the present embodiment.