Single-phase DC permanent magnet brushless motor controller, control method and motor power system

Abstract

The present invention discloses a controller and a control method for a single-phase DC permanent magnet brushless motor used in a near-space airship motor power system. The controller includes: a position signal acquisition module, a pulse duty ratio calculation module, a pulse switching module, and a pulse output module. Among them, the position signal acquisition module is connected to the pulse switching module, the pulse output module is connected to the pulse duty ratio calculation module and the pulse switching module. The pulse output module includes two timers, and the two timers respectively generate two paths of pulse square waves and adjust the duty ratio of the pulse square waves output by the timers according to the pulse duty ratio. The pulse switching module is used to determine whether to switch the pulse output state according to the rotor position information and the current pulse output state. The processor of the present invention judges the motor rotor position through the level signals of the high and low levels of the input / output ports, and then controls the start and operation of the motor.

Description

Technical Field

[0001] The present invention relates to a power propulsion motor controller, and more particularly to a controller for a single-phase DC permanent magnet brushless motor. Background Art

[0002] Currently, under the guidance of the development of science and technology and the national strategy of energy conservation and emission reduction, permanent magnet motor power systems are widely used in manufacturing fields such as electric vehicles, high-speed rails, near space, and aviation. This power system mainly includes a drive controller and a brushless permanent magnet motor. Among them, the brushless permanent magnet motor mainly includes brushless permanent magnet synchronous motors, brushless permanent magnet DC motors, and brushless permanent magnet single-phase DC motors, etc. The control function and performance of the drive controller largely determine the power economy, smoothness, braking performance, safety, and reliability of the mobile platform.

[0003] Traditional motors are mostly three-phase motors, and the control technology is relatively mature, all of which are controlled by means of excitation compensation. Currently, the controllers represented by DC permanent magnet brushless motor controllers are basically three-phase motors and their control systems. Single-phase DC motors have no position sensors. Due to the starting and running dead points of the motor, the starting control performance is poor, which makes it difficult for single-phase DC motor controllers to develop.

[0004] The above information disclosed in the background art section is only used to enhance the understanding of the background of the present invention. Therefore, it may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0005] The present invention provides a control method and a controller for a single-phase DC permanent magnet brushless motor, thereby at least to some extent overcoming one or more problems caused by the limitations and defects of the prior art.

[0006] According to a first aspect of the present invention, there is disclosed a controller for a single-phase DC permanent magnet brushless motor, characterized by comprising: a position signal acquisition module, a pulse duty ratio calculation module, a pulse switching module, and a pulse output module; wherein,

[0007] The position signal acquisition module is connected to the pulse switching module and is used to acquire rotor position information, and the rotor position information includes the starting position of the motor rotor and the running position of the motor rotor;

[0008] The pulse duty ratio calculation module is connected to the pulse output module and is used to obtain the pulse duty ratio according to the given speed and send the pulse duty ratio to the pulse output module;

[0009] The pulse output module is connected to the pulse duty cycle calculation module and the pulse switching module, and is used to output a pulse square wave according to the pulse duty cycle for the pulse square wave selected by the pulse switching module. The pulse output module includes two timers, which respectively generate two paths of pulse square waves and adjust the duty cycle of the pulse square wave output by the timer according to the pulse duty cycle. Under the switching of the pulse switching module, the pulse output module outputs one of the pulse square waves;

[0010] The pulse switching module is connected to the position signal acquisition module and the pulse output module, and is used to determine whether to switch the pulse output state according to the rotor position information and the current pulse output state. If so, it switches the currently output pulse square wave to another path of pulse square wave; otherwise, it does not switch the currently output pulse square wave.

[0011] According to an exemplary embodiment of the present invention, the controller further includes a start module, which is connected to the position signal acquisition module and the pulse output module, and is used to detect a start signal, trigger the pulse output module to output a pulse and start the motor, and also determine whether the motor is successfully started by monitoring the rotor position information.

[0012] According to an exemplary embodiment of the present invention, the position signal acquisition module includes a position availability judgment module, which is used to judge whether the acquired position signal is available according to the equipment operation stage and the current pulse output state. If it is available, the position signal is retained.

[0013] According to an exemplary embodiment of the present invention, the pulse duty cycle calculation module is further connected to the position signal acquisition module. The pulse duty cycle calculation module includes a speed feedback module, a current feedback module, a speed regulator, and a current regulator. The speed feedback module is connected to the speed regulator and is used to obtain the actual speed of the motor according to the rotor position information and transmit the actual speed of the motor to the speed regulator. The current feedback module is connected to the current regulator and is used to collect the current of the motor drive circuit and transmit the current to the current regulator. The speed regulator is used to perform speed regulation according to the given speed and the actual speed of the motor. The current regulator is connected to the speed regulator and is used to perform current regulation according to the result of speed regulation and the current of the motor drive circuit to obtain the pulse duty cycle.

[0014] According to an exemplary embodiment of the present invention, the controller is an MCU processor. MCU (Microcontroller Unit) is a micro control unit, also known as a single-chip microcomputer or a microcontroller. It appropriately reduces the frequency and specifications of the central processing unit, and integrates peripheral interfaces such as memory, counter, USB, A / D conversion, UART, PLC, DMA, and even LCD drive circuits on a single chip to form a chip-level computer for different combinations of control for different application scenarios.

[0015] According to an exemplary embodiment of the present invention, the controller is a control chip of STM32F103RCT6.

[0016] According to a second aspect of the present invention, a control method for a single-phase DC permanent magnet brushless motor is disclosed, including the following steps:

[0017] Circularly obtain the current rotor position information and the current output pulse state;

[0018] Control the motor to run at a given speed. The method for controlling the motor to run at a given speed includes: obtaining the given speed and obtaining the pulse duty cycle according to the given speed; determining whether to switch the pulse output state according to the current rotor position information and the current output pulse state. If so, switch the current pulse output to another pulse output. Otherwise, adjust the pulse duty cycle of the current pulse output according to the pulse duty cycle.

[0019] According to an exemplary embodiment of the present invention, before obtaining the given speed, first circularly detect the start signal. After detecting the start signal, start the motor. The method for starting the motor includes: intermittently triggering the output pulse according to the current rotor position information, and real-time monitoring the motor speed and rotation direction within a given time. If the rotor does not rotate smoothly or the direction is incorrect, restart the motor. If the rotor rotates smoothly and the direction is correct, transfer to the normal operation program of the motor.

[0020] According to an exemplary embodiment of the present invention, the method for obtaining the pulse duty cycle according to the given speed includes: performing a speed PID operation according to the given speed and the actual motor speed, and then performing a current PID operation according to the result of the speed PID operation and the current of the drive circuit to obtain the pulse duty cycle. PID is the abbreviation of Proportional, Integral, and Differential. As the name implies, the PID control algorithm is a control algorithm that combines three links of proportional, integral, and differential. It is the most mature and widely applied control algorithm in continuous systems.

[0021] According to an exemplary embodiment of the present invention, the method for determining whether to switch the pulse output state according to the current rotor position information and the current pulse output state includes: if the rotor position remains unchanged, do not switch the pulse output; if the rotor position changes, turn off the current pulse output, and then activate another pulse output.

[0022] According to the third aspect of the present invention, a single-phase DC permanent magnet brushless motor power system is disclosed, which includes the controller of the single-phase DC permanent magnet brushless motor, the motor, and the motor drive circuit. The motor drive circuit includes a power control element. The pulse output module of the controller is connected to the power control element, and the controller controls the rotation of the motor through the power control element.

[0023] According to the fourth aspect of the present invention, an airship in the near space is disclosed, which includes the single-phase DC permanent magnet brushless motor power system.

[0024] The positive effects of the present invention are as follows:

[0025] The solution of the present invention can well provide a control strategy for the single-phase permanent magnet DC motor, solve the problem of control dead points existing in single-phase motors for a long time, and the superiority of the present invention is elaborated as follows:

[0026] 1. The present invention takes the MCU processor as the control core, realizes judging the position of the motor rotor through the level signals of the input and output ports of the MCU processor, and then controls the startup and operation of the motor.

[0027] 2. The MCU processor performs pulse width modulation output control through the motor rotor position signal, feedback speed, given speed, and feedback current signal, so that the single-phase motor is at multiple optimal operating points, and the motor can be in control states such as non-differential startup, acceleration, cruising, and stopping at any time, effectively solving the problem of control dead points existing in single-phase motors for a long time, overcoming the problem that the square wave winding of the single-phase motor is sensitive to phase shift, and there is a square wave superposition phenomenon, resulting in energy control distortion and efficiency reduction. It has beneficial effects such as reasonable design and easy implementation.

[0028] 3. The present invention generates a pulse square wave through the MCU timer, controls the high voltage through low voltage timing, and reduces potential safety hazards to people.

[0029] 4. The present invention adopts a double closed-loop control system for pulse width modulation, combines the current loop and the speed loop, has excellent speed response and regulation characteristics, can adjust the speed of the motor to high speed, medium speed or low speed, and can also perform automatic cruising, so that the motor advances at a constant speed without being affected by conversion.

[0030] It should be understood that the above general description and the following detailed description are only exemplary and do not limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] By referring to the accompanying drawings and describing its exemplary embodiments in detail, the above and other objectives, features, and advantages of the present invention will become more obvious.

[0032] Figure 1Shows the controller connection diagram of the present invention.

[0033] Figure 2 Shows the internal module relationship diagram of the pulse duty cycle calculation module of the present invention.

[0034] Figure 3 Shows the overall flowchart of the control method of the present invention.

[0035] Figure 4 Shows the flowchart for judging the position of the motor rotor of the present invention.

[0036] Figure 5 Shows the flowchart for starting the motor of the present invention.

[0037] Figure 6 Shows the flowchart for the motor to run of the present invention.

[0038] Figure 7 Shows the flowchart for speed regulation of the present invention. Detailed implementation manners

[0039] Now, the exemplary embodiments will be described more fully with reference to the accompanying drawings. However, the exemplary embodiments can be implemented in various forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the description of the present invention will be more complete and comprehensive, and the concept of the exemplary embodiments will be fully conveyed to those skilled in the art. The drawings are merely schematic illustrations of the present invention and are not necessarily drawn to scale.

[0040] In addition, the described features, structures or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of the embodiments of the present invention. However, those skilled in the art will realize that the technical solutions of the present invention can be practiced without one or more of the specific details, or other methods, components, steps, etc. can be adopted. In other cases, well-known structures, methods, implementations or operations are not shown or described in detail to avoid obscuring various aspects of the present invention.

[0041] As the first embodiment of the present invention, the purpose of the present invention is to disclose a controller for a single-phase DC permanent magnet brushless motor. In this embodiment, an MCU controller with the model number STM32F103RCT6 is taken as an example. As Figure 1 shown, it includes: a position signal acquisition module, a start module, a pulse duty cycle calculation module, a pulse switching module, and a pulse output module; among them, the position signal acquisition module is connected to the pulse switching module, the start module, and the pulse duty cycle calculation module, and the pulse output module is connected to the start module and the pulse duty cycle calculation module.

[0042] The position signal acquisition module acquires the rotor position information from the Hall element, and judges through MCU signal interruption and interference recheck. The rotor position information includes the starting position of the motor rotor and the running position of the motor rotor. The acquisition ports of the position signal acquisition module are two, namely Port PB0 and Port PB1. Port PB0 acquires the starting position signal of the motor rotor, and Port PB1 acquires the running position signal of the motor rotor. The signals received by Port PB0 and Port PB1 are high and low levels 1 and 0. The position signal acquisition module also includes a position availability judgment module. After acquiring the rotor position information, the position availability judgment module judges whether the acquired position signal is available according to the equipment operation stage and the current pulse output state. If it is available, the position signal is retained.

[0043] The start module is used to detect the start signal and trigger the output pulse of the pulse output module to start the motor. By monitoring the rotor position information, it judges whether the motor rotates smoothly and in the correct direction. If the motor rotates smoothly and in the correct direction, the motor is successfully started.

[0044] The pulse duty cycle calculation module is used to obtain the pulse duty cycle according to the given speed and send the pulse duty cycle to the pulse output module. As Figure 2 shown, the pulse duty cycle calculation module includes: a speed feedback module, a current feedback module, a speed regulator and a current regulator; the speed feedback module is connected to the speed regulator, and the current regulator is connected to the current feedback module and the speed regulator. The speed feedback module is used to obtain the actual speed of the motor according to the rotor position information and transmit the actual speed of the motor to the speed regulator. The speed regulator is used to adjust the speed according to the given speed and the actual speed of the motor. The current feedback module is used to collect the current of the motor drive circuit and transmit the current to the current regulator. The current regulator adjusts the current according to the result of speed regulation and the current of the motor drive circuit to obtain the pulse duty cycle.

[0045] The pulse output module is used to output a pulse square wave. The pulse output module includes two timers, namely TIM3 and TIM4. The two timers respectively generate two paths of pulse square waves and adjust the duty cycle of the pulse square wave output by the timer according to the pulse duty cycle. Under the switching of the pulse switching module, the pulse output module outputs one of the pulse square waves.

[0046] The pulse switching module determines whether to switch the pulse output state according to the rotor position information and the current pulse output state. If so, it switches the currently output pulse square wave to the other path of pulse square wave. Otherwise, it does not switch the currently output pulse square wave.

[0047] The motor is controlled by the above controller. As Figure 3 shown, the following control method is adopted:

[0048] Turn on the controller, initialize the I / O ports, clock, timer, etc. of the controller. After the controller is turned on, continuously obtain the current rotor position information and the current output pulse status;

[0049] After detecting the start signal, start the motor;

[0050] Run at the given speed. The method of running at the given speed includes: obtaining the given speed and getting the pulse duty cycle according to the given speed; determining whether to switch the pulse output status based on the current rotor position information and the current output pulse status. If so, switch the current pulse output to another pulse output. Otherwise, adjust the pulse duty cycle of the current pulse output according to the pulse duty cycle.

[0051] The method of obtaining the current rotor position information is as follows: As Figure 4 shown, read the position information of the rotor through an external Hall element. The PB0 interrupt indicates collecting the starting position of the rotor, and the PB1 port interrupt indicates collecting the running position of the rotor. Then, judge whether the signal is available according to the judgment of the equipment operation stage, and then judge whether the currently collected signal is available according to the current pulse output status. If it is available, it means the signal is normal and output the position signal. If it is not available, do not output the position signal. The equipment operation stage includes the starting stage and the running stage.

[0052] The method of starting the motor includes: As Figure 5 shown, after detecting the start signal, intermittently trigger the start command according to the current rotor position information, output pulses to make the motor rotate, and continuously monitor the motor speed and rotation direction within the given time. If the rotor does not rotate smoothly or the direction is incorrect, the start is unsuccessful and the motor is restarted; if the rotor rotates smoothly and the direction is correct, the start is successful, the motor starting stage ends, switch to the running state, and transfer to the normal motor operation program, and the motor enters the running stage.

[0053] The method of running at the given speed includes: As Figure 6 and Figure 7 shown, obtain the actual motor speed by collecting the position of the rotor, which is the Figure 7 speed n. Perform speed feedback on the speed regulator with the actual motor speed. The speed regulator performs speed PID operation on the given speed and the actual motor speed. Then, the current regulator performs current PID operation according to the result of the speed PID operation and the current of the drive circuit to obtain the pulse duty cycle, Figure 7In this, PWM means Pulse Width Modulation; when the level of the rotor position is 1, the pulse is output by TIM4. If the rotor position changes, the TIM4 pulse output is turned off, and the TIM3 pulse output is activated. If the rotor position does not change, the pulse duty cycle is transmitted to TIM4 to adjust the output duty cycle; when the level of the rotor position is 0, the pulse is output by TIM3. If the rotor position changes, the TIM3 pulse output is turned off, and the TIM4 pulse output is activated. If the rotor position does not change, the pulse duty cycle is transmitted to TIM3 to adjust the output duty cycle. In this embodiment, with the MCU processor as the control core, it realizes judging the motor rotor position through the level signals of the high and low levels of the input and output ports of the MCU processor, and then controlling the start and operation of the motor; generating a pulse square wave through the MCU timer, controlling the high voltage through the low voltage timing to reduce potential safety hazards to people; the MCU processor also performs pulse width modulation output control through the motor rotor position signal, feedback speed, given speed, and feedback current signal to prevent square wave superposition and overcome the dead point problem of single-phase motors.

[0054] As the second embodiment of the present invention, the purpose of the present invention is to disclose a single-phase DC permanent magnet brushless motor power system, including the controller, motor, and motor drive circuit of the single-phase DC permanent magnet brushless motor in the first embodiment. The motor drive circuit includes a power control element. The pulse output module of the controller is connected to the power control element, and the controller controls the rotation and operation of the motor through the power control element.

[0055] As the third embodiment of the present invention, the purpose of the present invention is to disclose an airship in the near space, including the single-phase DC permanent magnet brushless motor power system in the second embodiment.

[0056] After considering the specification and practicing the invention disclosed herein, those skilled in the art will readily conceive of other embodiments of the present invention. This application is intended to cover any variations, uses, or adaptations of the present invention, which follow the general principles of the present invention and include common general knowledge or conventional technical means in the technical field not disclosed by the present invention. The specification and examples are only regarded as exemplary, and the true scope and spirit of the present invention are pointed out by the following claims.

[0057] It should be understood that the present invention is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present invention is only limited by the appended claims.

Claims

1. A controller for a single-phase DC permanent magnet brushless motor, characterized in that, the controller is an MCU processor, including: a position signal acquisition module, a pulse duty cycle calculation module, a pulse switching module, and a pulse output module; wherein, the position signal acquisition module is connected to the pulse switching module and is used to acquire rotor position information, and the rotor position information includes the starting position of the motor rotor and the running position of the motor rotor; there are two acquisition ports for the position signal acquisition module, namely port PB0 and port PB1. Port PB0 acquires the starting position signal of the electronic rotor, and port PB1 acquires the running position signal of the motor rotor. The signals received by port PB0 and port PB1 are high and low levels; the position signal acquisition module includes a position availability judgment module, and the position availability judgment module is used to judge whether the acquired position signal is available according to the equipment operation stage and the current pulse output state. If it is available, the position signal is retained; the equipment operation stage includes a starting stage and a running stage; the pulse duty cycle calculation module is connected to the pulse output module and is used to obtain the pulse duty cycle according to the given speed and send the pulse duty cycle to the pulse output module; the pulse output module is connected to the pulse duty cycle calculation module and the pulse switching module and is used to output a pulse square wave. The pulse output module includes two timers, and the two timers respectively generate two paths of pulse square waves and adjust the duty cycle of the pulse square waves output by the timers according to the pulse duty cycle. Under the switching of the pulse switching module, the pulse output module outputs one of the pulse square waves; the pulse switching module is connected to the position signal acquisition module and the pulse output module and is used to determine whether to switch the pulse output state according to the rotor position information and the current pulse output state. If so, switch the currently output pulse square wave to the other path of pulse square wave, otherwise, do not switch the currently output pulse square wave; the controller further includes a starting module, and the starting module is connected to the position signal acquisition module and the pulse output module and is used to detect the starting signal, trigger the pulse output module to output a pulse to start the motor, and also judge whether the motor starts successfully by monitoring the rotor position information; after detecting the starting signal, intermittently trigger the starting command according to the current rotor position information, output a pulse to make the motor rotate, and monitor the motor speed and rotation direction in real time within a given time. If the rotor does not rotate smoothly or the direction is incorrect, the start is unsuccessful and the motor is restarted; if the rotor rotates smoothly and the direction is correct, the start is successful, the motor starting stage ends, the operation state is switched, and the motor normal operation program is entered, and the motor enters the running stage.

2. The controller for a single-phase DC permanent magnet brushless motor according to claim 1, characterized in that, the pulse duty cycle calculation module is further connected to the position signal acquisition module, and the pulse duty cycle calculation module includes a speed feedback module, a current feedback module, a speed regulator, and a current regulator; the speed feedback module is connected to the speed regulator and is used to obtain the actual speed of the motor according to the rotor position information and transmit the actual speed of the motor to the speed regulator; The current feedback module is connected to the current regulator and is used to collect the current of the motor drive circuit and transmit the current to the current regulator; The speed regulator is used to perform speed regulation according to the given speed and the actual speed of the motor; The current regulator is connected to the speed regulator and is used to perform current regulation according to the result of speed regulation and the current of the motor drive circuit to obtain the pulse duty ratio.

3. A control method for a single-phase DC permanent magnet brushless motor, characterized in that, using the controller of the single-phase DC permanent magnet brushless motor according to claim 1 or 2, comprising the following steps: Circularly obtain the current rotor position information and the current output pulse state; Control the motor to run at a given speed. The method for controlling the motor to run at a given speed includes: obtaining the given speed and obtaining the pulse duty ratio according to the given speed; determining whether to switch the pulse output state according to the current rotor position information and the current output pulse state. If so, switch the current pulse output to another pulse output. Otherwise, adjust the pulse duty ratio of the current pulse output according to the pulse duty ratio; Before obtaining the given speed, first circularly detect the start signal. After detecting the start signal, start the motor. The method for starting the motor includes: intermittently trigger the output pulse according to the current rotor position information, and real-time monitor the motor speed and rotation direction within a given time. If the rotor does not rotate smoothly or the direction is incorrect, restart the motor.

4. The control method for a single-phase DC permanent magnet brushless motor according to claim 3, characterized in that, The method for obtaining the pulse duty ratio according to the given speed includes: performing speed PID operation according to the given speed and the actual speed of the motor, and then performing current PID operation according to the result of the speed PID operation and the current of the drive circuit to obtain the pulse duty ratio.

5. The control method for a single-phase DC permanent magnet brushless motor according to claim 3, characterized in that, The method for determining whether to switch the pulse output state according to the current rotor position information and the current output pulse state includes: if the rotor position remains unchanged, do not switch the pulse output; if the rotor position changes, turn off the current pulse output, and then activate another pulse output.

6. A single-phase DC permanent magnet brushless motor power system, characterized in that, comprising the controller of the single-phase DC permanent magnet brushless motor according to claim 1 or 2, a motor and a motor drive circuit. The motor drive circuit includes a power control element. The pulse output module of the controller is connected to the power control element, and the controller controls the motor to rotate and run through the power control element.

7. An airship in the near space, characterized in that, comprising: The single-phase DC permanent magnet brushless motor power system according to claim 6.

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