CN105515469A - Brushless DC motor and its control method and device - Google Patents

Abstract

The invention discloses a brushless direct current motor and a control method and a control device thereof, wherein the control method comprises the following steps: receiving a motor shutdown signal; controlling the motor to shut down, and controlling the rotor to be positioned after the motor is shut down; receiving a starting signal of a motor; and controlling the motor to accelerate and switch modes according to the starting signal. The method effectively solves the problem of reversal phenomenon when the motor is started by controlling the rotor to be positioned after the motor is shut down and directly controlling the motor to accelerate and switch modes when the motor is restarted.

Description

Brushless DC motor and its control method and device

technical field

The invention relates to the technical field of motor control, in particular to a brushless DC motor and its control method and device.

Background technique

Generally, there are two starting control methods for brushless DC motors without position sensors, one is the high-frequency signal input method, which is prone to torque ripple; the other is a three-stage starting method, including rotor positioning, acceleration and There are three phases of running state switching.

In the three-stage starting method, the rotor positioning is to control the conduction of any two phases of the inverter to pull the rotor to the predetermined position, so as to complete the positioning of the rotor, but this positioning method will cause 50% of the motor to start. Chances are reversed. For example, when the fan is powered on, it may first rotate in reverse and then forward, affecting user experience. Therefore, there is a need to improve the start-up control of the motor.

Contents of the invention

The present invention aims to solve one of the technical problems in the related art at least to a certain extent. For this reason, an object of the present invention is to propose a control method for a brushless DC motor, by controlling the rotor positioning after the motor is turned off, and directly controlling the motor to accelerate and mode switch when the motor is restarted, thereby effectively solving the problem of motor startup. Inversion occurs.

Another object of the present invention is to provide a control device for a brushless DC motor. Another object of the present invention is to provide a brushless DC motor.

In order to achieve the above object, an embodiment of the present invention proposes a control method for a brushless DC motor, including the following steps: receiving a motor shutdown signal; controlling the motor to shutdown, and controlling the rotor after the motor shutdown Positioning; receiving a power-on signal of the motor; and controlling the motor to accelerate and switch modes according to the power-on signal.

The control method of the brushless DC motor in the embodiment of the present invention controls the positioning of the rotor after the motor is turned off, and directly controls the motor to perform acceleration and mode switching when the motor is restarted, thereby effectively solving the phenomenon of reverse rotation when the motor is started, and is simple. Easy to operate and high reliability.

According to an embodiment of the present invention, after receiving the power-on signal of the motor, it further includes: judging whether it is the first startup; if it is judged to be the first startup, controlling the positioning of the rotor, and controlling The motor is accelerated and mode switched.

According to an embodiment of the present invention, the above-mentioned method for controlling the brushless DC motor further includes: initializing the motor.

According to an embodiment of the present invention, after controlling the positioning of the rotor after the motor is turned off, it further includes: judging whether the position of the rotor changes; if the position of the rotor changes, after receiving the Control the positioning of the rotor after the power-on signal, and control the motor to accelerate and switch modes after the positioning of the rotor.

In order to achieve the above object, another embodiment of the present invention proposes a control device for a brushless DC motor, including: a shutdown signal receiving module for receiving a shutdown signal of the motor; a shutdown control module for controlling the motor to shut down a positioning module, used to control the positioning of the rotor after the motor is shut down; a power-on signal receiving module, used to receive the power-on signal of the motor; and a power-on control module, used to control the motor according to the power-on signal Accelerate and make a mode switch.

The control device of the brushless DC motor in the embodiment of the present invention controls the positioning of the rotor after the motor is turned off, and directly controls the motor to perform acceleration and mode switching when the motor is restarted, thereby effectively solving the phenomenon of reverse rotation when the motor is started, and is reliable. high sex.

According to an embodiment of the present invention, the start-up control module is further configured to control the positioning of the rotor when it is judged to be starting for the first time, and control the motor to accelerate and switch modes after the rotor is positioned.

According to an embodiment of the present invention, the above-mentioned control device for a brushless DC motor further includes: an initialization module, configured to initialize the motor.

According to an embodiment of the present invention, the above-mentioned control device for a brushless DC motor further includes: a judging module for judging whether the rotor position changes, wherein the power-on control module judges whether the rotor position changes , control the positioning of the rotor, and control the motor to accelerate and switch modes after the positioning of the rotor.

In addition, an embodiment of the present invention also provides a brushless direct current motor, which includes the above-mentioned control device for a brushless direct current motor.

The brushless DC motor of the embodiment of the present invention, through the above-mentioned control device of the brushless DC motor, can control the positioning of the rotor after the motor is turned off, and directly control the motor to perform acceleration and mode switching when the motor is restarted, thereby effectively solving the problem of motor startup. inversion occurs.

According to an embodiment of the present invention, the brushless DC motor is not provided with a position sensor.

Description of drawings

FIG. 1 is a flowchart of a control method for a brushless DC motor according to an embodiment of the present invention.

Fig. 2 is a flowchart of a control method of a brushless DC motor according to a specific embodiment of the present invention.

FIG. 3 is a schematic block diagram of a control device for a brushless DC motor according to an embodiment of the present invention.

Fig. 4 is a schematic block diagram of a control device for a brushless DC motor according to a specific embodiment of the present invention.

detailed description

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

The brushless DC motor and its control method and device according to the embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a flowchart of a control method for a brushless DC motor according to an embodiment of the present invention. As shown in Figure 1, the control method of the brushless DC motor includes the following steps:

S1, receiving a motor shutdown signal.

S2, controlling the motor to shut down, and controlling the positioning of the rotor after the motor is shut down.

Specifically, when the motor shutdown signal is received, the motor is controlled to stop running, and when the motor is about to stop running, the motor is controlled to perform rotor positioning so that the rotor is positioned to a predetermined position. In one embodiment of the present invention, after the rotor is positioned successfully, the motor enters a standby state to initialize the motor.

S3, receiving a power-on signal of the motor.

S4, controlling the motor to accelerate and switch modes according to the power-on signal.

Specifically, when the motor is started again, since the rotor of the motor has been positioned to a predetermined position after the motor is turned off, the motor can be directly controlled to accelerate in the forward direction and switch modes, thereby effectively avoiding the reverse rotation phenomenon when the motor is started. Among them, when controlling the motor to accelerate running, the partition can be determined by giving a preset angular velocity value. After the partition is determined, the switching sequence of the switching tube such as IGBT (InsulatedGateBipolarTransistor, insulated gate bipolar transistor) can be obtained. By controlling the IGBT Turning on and off generates a certain rotating magnetic field. Under the action of the rotating magnetic field, the rotor starts to rotate, and then drives the motor to run. When the motor runs to a certain speed, it switches from open-loop control to closed-loop control, and the motor enters the normal operating state. .

In one embodiment of the present invention, after receiving the power-on signal of the motor, it also includes: judging whether it is the first start; if it is judged to be the first start, then controlling the positioning of the rotor, and controlling the motor to accelerate and switch modes after the positioning of the rotor .

It can be understood that when the motor is started for the first time, since the rotor of the motor has not been positioned before, it is necessary to control the positioning of the rotor first, and then control the acceleration of the motor and perform mode switching after the positioning of the rotor is successful. That is to say, when the motor starts for the first time, it can be positioned according to the rotor positioning method in the related art, and after the positioning is successful, the motor can be controlled to accelerate and switch modes. Start-up method to control the motor start-up operation.

In one embodiment of the present invention, after controlling the rotor positioning after the motor is turned off, it also includes: judging whether the rotor position changes; Then control the motor to accelerate and switch modes.

That is to say, when the rotor is in the standby state after successful positioning, if the position of the motor rotor changes due to human or external factors, when the motor starts up again, it is necessary to determine whether the rotor position has changed, and to control when the rotor position changes. Rotor positioning, when the rotor is positioned to a predetermined position, control the motor to accelerate and switch modes.

According to a specific embodiment of the present invention, as shown in Figure 2, the control method of the brushless DC motor may include the following steps:

S101, the motor is in a standby state, and the running parameters of the motor are initialized.

S102, judging whether the motor is started for the first time. If yes, execute step S103; if no, execute step S104.

S103, controlling the positioning of the rotor.

S104, judging whether the rotor position is correct. If yes, execute step S105; if no, return to step S103.

S105, the motor is in an open-loop state, that is, the motor is controlled to accelerate.

S106, when the current running state of the motor satisfies the mode switching condition, control the motor to enter a closed-loop state.

S107, judging whether the motor is turned off. If yes, execute step S108; if no, return to step S106.

S108, control the positioning of the rotor, and return to step S101 after the positioning of the rotor is successful.

To sum up, the control method of the brushless DC motor in the embodiment of the present invention controls the positioning of the rotor after the motor is turned off, and directly controls the motor to perform acceleration and mode switching when the motor is restarted, thereby effectively solving the problem of the reaction occurring when the motor is started. It is simple and easy to implement, and has high reliability, thereby improving the performance of related products and improving user experience.

FIG. 3 is a schematic block diagram of a control device 100 for a brushless DC motor according to an embodiment of the present invention. As shown in FIG. 3 , the control device 100 of the brushless DC motor includes a shutdown signal receiving module 10 , a shutdown control module 20 , a positioning module 30 , a startup signal receiving module 40 and a startup control module 50 .

Wherein, the shutdown signal receiving module 10 is used for receiving the shutdown signal of the motor, and the shutdown control module 20 is used for controlling the shutdown of the motor. The positioning module 30 is used to control the positioning of the rotor after the motor is turned off. The start-up signal receiving module 40 is used for receiving the start-up signal of the motor, and the start-up control module 50 is used for controlling the motor to accelerate and switch modes according to the start-up signal.

Specifically, when the shutdown signal receiving module 10 receives the motor shutdown signal, the shutdown control module 20 controls the motor to stop running, and when the motor is about to stop running, the positioning module 30 controls the motor to perform rotor positioning so that the rotor is positioned to a predetermined position. In an embodiment of the present invention, after the rotor is positioned successfully, the motor is also initialized through an initialization module (not specifically shown in the figure). When the motor starts again, that is, when the power-on signal receiving module 40 receives the power-on signal of the motor, since the rotor of the motor has been positioned to a predetermined position after the motor is turned off, the power-on control module 50 can directly control the motor to accelerate and proceed in the forward direction. Mode switching, so as to effectively avoid the phenomenon of reverse rotation when the motor starts. Wherein, when the start-up control module 50 controls the motor to accelerate operation, the partition can be determined by giving a preset angular velocity value, and the switching sequence of the switching tube such as IGBT (Insulated Gate Bipolar Transistor, Insulated Gate Bipolar Transistor) can be obtained after the partition is determined. , by controlling the IGBT on and off to generate a certain rotating magnetic field, the rotor starts to rotate under the action of the rotating magnetic field, and then drives the motor to run. When the motor runs to a certain speed, it switches from open-loop control to closed-loop control. into normal operation.

In an embodiment of the present invention, the start-up control module 50 is also used to control the positioning of the rotor when it is judged to be starting for the first time, and control the motor to accelerate and switch modes after the rotor is positioned.

It can be understood that when the motor is started for the first time, since the motor rotor has not been positioned before, the start-up control module 50 needs to control the rotor positioning first, and then control the motor to accelerate and perform mode switching after the rotor positioning is successful. That is to say, when the motor starts for the first time, it can be positioned according to the rotor positioning method in the related art, and after the positioning is successful, the motor can be controlled to accelerate and switch modes. Start-up method to control the motor start-up operation.

In an embodiment of the present invention, as shown in FIG. 4 , the above-mentioned control device 100 for a brushless DC motor further includes: a judging module 60 . The judging module 60 is used for judging whether the rotor position has changed. When judging that the rotor position has changed, the power-on control module 50 controls the positioning of the rotor, and controls the motor to accelerate and switch modes after the rotor is positioned.

That is to say, when the rotor is in the standby state after successful positioning, if the position of the motor rotor changes due to man-made or external factors, then when the motor starts up again, the judging module 60 needs to judge whether the rotor position has changed, and when the rotor position occurs When changing, the start-up control module 50 controls the positioning of the rotor, and when the rotor is positioned to a predetermined position, the motor is controlled to accelerate and switch modes.

The control device of the brushless DC motor in the embodiment of the present invention controls the positioning of the rotor after the motor is turned off, and directly controls the motor to perform acceleration and mode switching when the motor is restarted, thereby effectively solving the phenomenon of reverse rotation when the motor is started, and is reliable. High performance, thereby improving the performance of related products and improving user experience.

In addition, an embodiment of the present invention also provides a brushless direct current motor, which includes the above-mentioned control device for a brushless direct current motor. The brushless DC motor is not provided with a position sensor, wherein the position sensor refers to a Hall sensor or other possible sensors.

The brushless DC motor of the embodiment of the present invention, through the above-mentioned control device of the brushless DC motor, can control the positioning of the rotor after the motor is turned off, and directly control the motor to perform acceleration and mode switching when the motor is restarted, thereby effectively solving the problem of motor startup. inversion occurs.

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", "Axial", The orientation or positional relationship indicated by "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the referred device or element Must be in a particular orientation, be constructed in a particular orientation, and operate in a particular orientation, and therefore should not be construed as limiting the invention.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

In the present invention, unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection , or integrated; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise specified limit. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

In the present invention, unless otherwise clearly specified and limited, the first feature may be in direct contact with the first feature or the first and second feature may be in direct contact with the second feature through an intermediary. touch. Moreover, "above", "above" and "above" the first feature on the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. "Below", "beneath" and "beneath" the first feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is less horizontally than the second feature.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without conflicting with each other.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and those skilled in the art can make the above-mentioned The embodiments are subject to changes, modifications, substitutions and variations.

Claims (10)

1. A control method for a brushless DC motor, comprising the following steps: Receive motor shutdown signal; controlling the motor to shut down, and controlling the positioning of the rotor after the motor is shut down; receiving a power-on signal of the motor; and The motor is controlled to accelerate and switch modes according to the power-on signal. 2. The control method of the brushless DC motor according to claim 1, further comprising: Determine whether it is the first startup; If it is judged to be started for the first time, control the positioning of the rotor, and control the motor to accelerate and switch modes after the positioning of the rotor. 3. The control method of brushless DC motor as claimed in claim 1, is characterized in that, also comprises: Initialize the motor. 4. The control method of a brushless DC motor according to claim 1, further comprising: judging whether the rotor position changes; If the position of the rotor changes, the positioning of the rotor is controlled after receiving the power-on signal, and the motor is controlled to accelerate and switch modes after the positioning of the rotor. 5. A control device for a brushless DC motor, characterized in that it comprises: The shutdown signal receiving module is used to receive the shutdown signal of the motor; Shutdown control module, used to control the motor to shut down; a positioning module, configured to control the positioning of the rotor after the motor is shut down; A power-on signal receiving module, configured to receive a power-on signal of the motor; and The power-on control module is used to control the motor to accelerate and switch modes according to the power-on signal. 6. The control device of a brushless DC motor according to claim 5, wherein the start-up control module is further configured to control the positioning of the rotor when it is judged to be starting for the first time, and after the positioning of the rotor The motor is controlled to accelerate and switch modes. 7. The control device of the brushless DC motor as claimed in claim 5, further comprising: The initialization module is used to initialize the motor. 8. The control device of the brushless DC motor as claimed in claim 5, further comprising: A judging module, configured to judge whether the rotor position changes, wherein the power-on control module controls the positioning of the rotor when judging that the rotor position changes, and controls the motor to accelerate after the rotor is positioned and switch modes. 9. A brushless direct current motor, characterized in that it comprises a control device for a brushless direct current motor according to any one of claims 5-8. 10. The brushless DC motor according to claim 9, characterized in that the brushless DC motor is not provided with a position sensor.