Motor control circuit and multi-pole direct current motor

Abstract

The invention discloses a motor control circuit which comprises a controller, and the controller is integrated with a rectification part used for converting alternating current into pulse direct current and enabling the pulse direct current to become variable direct current voltage; the filtering part is used for smoothing the rectified pulse direct current; the voltage stabilizing part ensures that the output voltage is stable; a PWM control section for generating a PWM signal and controlling the speed and direction of the motor by changing the duty ratio; the protection circuit is used for protecting the circuit system from overload, short circuit and reverse voltage damage; the motor driver is used for controlling the current direction so as to control the positive and negative rotation of the direct-current motor; wherein an alternating current power supply is connected to the input end of the arrangement part, the output end of the rectification part is connected to the two ends of the filtering part, the output end of the filtering part is connected to the input end of the voltage stabilization part, the output end of the voltage stabilization part is connected to the power supply input of the PWM control part, and the output end of the motor driver is used for being connected to a direct current motor.

Description

Technical Field

[0001] The present application relates to the technical field of motors and motor control, and in particular to a motor control circuit and a multi-pole DC motor. Background Art

[0002] With the development of the power tool industry, the requirements for motor efficiency and torque are increasing. Although traditional DC motors are widely used, they have problems such as low efficiency, high heat generation, and bulky size in low-speed and high-torque application scenarios. To solve these problems, the existing technology often uses complex and costly reduction systems to increase torque, which not only increases the weight and cost of power tools, but also reduces overall efficiency.

[0003] In terms of motor control, although PWM (pulse width modulation) technology has been widely used in motor speed control, traditional motor control circuit design often fails to fully utilize the potential of multi-pole motors, resulting in limited motor performance. In addition, due to the lack of effective thermal management and protection circuits, the motor is easily damaged in overload or short circuit conditions, affecting its service life. Summary of the invention

[0004] The technical solution adopted by the present application to solve the technical problem is: the motor control circuit includes a controller, and the controller is integrated with:

[0005] The rectifier part is used to convert the alternating current into pulsed direct current, making it a variable direct current voltage;

[0006] The filtering part is used to smooth the pulsed DC after rectification;

[0007] Voltage stabilization part, ensuring stable output voltage;

[0008] PWM control part, used to generate PWM signal and control the motor speed and direction by changing the duty cycle;

[0009] Protection circuits, used to protect circuit systems from overload, short circuit and reverse voltage damage;

[0010] Motor drive, used to control the direction of current, thereby controlling the forward and reverse rotation of the DC motor;

[0011] Among them, the AC power supply is connected to the input end of the sorting part, the output end of the rectifying part is connected to the two ends of the filtering part, the output end of the filtering part is connected to the input end of the voltage stabilizing part, the output end of the voltage stabilizing part is connected to the power input of the PWM control part, and the output end of the motor drive is used to connect to the DC motor.

[0012] In some embodiments, the rectifying part is used to convert an input first voltage into a second voltage, then step down the voltage into the first voltage, and input it to the motor; wherein the first voltage is less than the second voltage.

[0013] In some embodiments, the value of the first voltage is 90V-260V, preferably greater than or equal to 220V.

[0014] In some embodiments, the rectifying part is used to convert an input first voltage into a second voltage and input the second voltage to the motor, wherein the first voltage is lower than the second voltage.

[0015] In some embodiments, the value of the second voltage is 260 V-60 V. Preferably, the value of the first voltage is less than 220 V, and the value of the second voltage is greater than or equal to 220 V.

[0016] In some embodiments, the rectifying part is a rectifying bridge, which is composed of four diodes and converts alternating current into pulsed direct current; during the positive half cycle, two diagonal diodes are turned on; during the negative half cycle, the other two diagonal diodes are turned on.

[0017] In some embodiments, the filtering part is a filtering capacitor.

[0018] In some embodiments, the voltage stabilizing part is a voltage stabilizer or a switching power supply.

[0019] In some embodiments, the PWM control part is a microcontroller or an application specific integrated circuit.

[0020] In some embodiments, the protection circuit includes overload protection and / or reverse voltage protection.

[0021] In some embodiments, the motor driver is an H-bridge circuit composed of four MOS tubes.

[0022] Another aspect of the present application provides a multi-pole DC motor, which includes at least N pairs of stator magnets (a pair of stator magnets here includes a pair of S poles and an N pole), where N is an even number greater than or equal to 2, so as to form a multi-pole magnetic field; the motor also includes corresponding rotor windings to achieve high-efficiency power conversion; and the motor works in conjunction with the motor control circuit described in any of the above embodiments, wherein the PWM control part controls the speed and direction of the motor by precisely adjusting the width of the current pulse, and the motor drive part is responsible for converting the control signal into the actual action of the motor.

[0023] In some embodiments, the number of the stator magnet tiles is 4.

[0024] In some embodiments, a closed-loop control system is established between the PWM control part, the motor drive part and the multi-pole DC motor. By detecting the real-time speed and load conditions of the motor, the duty cycle of the PWM signal is dynamically adjusted to achieve fine control of the motor speed and torque, thereby ensuring that the motor can operate efficiently and stably under various working conditions.

[0025] In some embodiments, as the power of the multi-stage DC motor increases, the voltage input to the motor by the motor control circuit also increases. During this process, the increase in current is zero or less than the increase in voltage.

[0026] The beneficial effects of this application are:

[0027] 1. By adopting a multi-pole design, the motor can provide high torque at low speed, while reducing the operating current and reducing the heat loss caused by the current, thereby significantly improving the motor efficiency.

[0028] 2. In the application of power tools, the traditional deceleration system can be eliminated or simplified, making the overall structure of the power tool more compact, lighter, and less costly, thereby improving the portability and market competitiveness of the product.

[0029] 3. By reducing the working current, the heating of the motor is effectively reduced. Combined with the optimized thermal design, the thermal stability of the motor is improved and the service life is extended.

[0030] In summary, the multi-pole DC motor and its control circuit proposed in this application significantly improve the performance of power tools by optimizing motor design and control strategy, meeting the needs of modern industrial and consumer markets for high-efficiency, high-torque, lightweight and intelligent power tools. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present application is further described below in conjunction with the accompanying drawings and embodiments.

[0032] Figure 1 It is a connection diagram of the control motor and the motor of the present application. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to achieve. When the combination of technical solutions is contradictory or cannot be achieved, it should be considered that the combination of such technical solutions does not exist and is not within the scope of protection of this application.

[0034] Please refer to Figure 1 As shown, it is a specific implementation method of this application:

[0035] A motor control circuit, the motor control circuit includes a controller, the controller is integrated with: a rectifier part, used to convert alternating current into pulse direct current; a filter part, used to smooth the rectified pulse direct current to make it a relatively stable direct current voltage; a voltage stabilization part, to ensure that the output voltage is stable and is not affected by input voltage fluctuations; a PWM control part, used to generate a PWM signal, and control the motor speed and direction by changing the duty cycle; a protection circuit, used to protect the circuit system from overload, short circuit and reverse voltage damage; a motor drive, used to control the direction of the current, thereby controlling the forward and reverse rotation of the DC motor;

[0036] Among them, the AC power supply is connected to the input end of the sorting part, the output end of the rectifying part is connected to the two ends of the filtering part, the output end of the filtering part is connected to the input end of the voltage stabilizing part, the output end of the voltage stabilizing part is connected to the power input of the PWM control part, and the output end of the motor drive is used to connect to the DC motor.

[0037] Preferably, the rectifying part is a rectifying bridge, which is composed of four diodes, and converts the alternating current into pulsed direct current; during the positive half cycle, two diagonal diodes are turned on; during the negative half cycle, the other two diagonal diodes are turned on.

[0038] Preferably, the filtering part is a filtering capacitor, which is used to smooth the rectified pulse direct current to make it a relatively stable direct current voltage. A large-capacity electrolytic capacitor is usually used.

[0039] Optionally, the voltage stabilization part is a voltage stabilizer or a switching power supply. It ensures that the output voltage is stable and is not affected by input voltage fluctuations. It is necessary for applications that require precise voltage control, such as PWM controlled motors.

[0040] Optionally, the PWM control part is a microcontroller or a dedicated integrated circuit, which is used to generate a PWM signal to control the speed and direction of the motor by changing the duty cycle.

[0041] In some embodiments, the protection circuit includes overload protection and / or reverse voltage protection. Among them, overload protection: can include a thermistor, a fuse or an overcurrent protection chip to prevent overload from damaging the motor or power supply. Reverse voltage protection: a diode or MOS tube is used to prevent damage caused by reverse connection of the battery.

[0042] In some embodiments, the motor driver is an H-bridge circuit, which is composed of four transistors (usually MOS tubes or IGBTs) and can control the direction of current, thereby controlling the forward and reverse rotation of the DC motor.

[0043] As one embodiment, the rectifier part is used to convert the input first voltage into a second voltage, then step it down to the first voltage, and input it to the motor; wherein the first voltage is less than the second voltage. In this embodiment, the value of the first voltage is greater than or equal to 220V. For example, if the input voltage is 220V, it is rectified to 310V by the rectifier part, and then stepped down to 220V by the control circuit and input to the motor.

[0044] As another embodiment, the rectifier part is used to convert the input first voltage into a second voltage and input it to the motor, wherein the first voltage is less than the second voltage. In this embodiment, the value of the first voltage is less than 220V, and the value of the second voltage is greater than or equal to 220V. For example, if the input is 127V, it is rectified to 220V by the rectifier part and then input to the motor.

[0045] Another aspect of the present application provides a multi-pole DC motor, which includes at least N pairs of stator magnets (a pair of stator magnets here includes a pair of S poles and an N pole), where N is an even number greater than or equal to 2, so as to form a multi-pole magnetic field; the motor also includes corresponding rotor windings to achieve high-efficiency power conversion; and the motor works in conjunction with the motor control circuit described in any of the above embodiments, wherein the PWM control part controls the speed and direction of the motor by precisely adjusting the width of the current pulse, and the motor drive part is responsible for converting the control signal into the actual action of the motor.

[0046] Reference Figure 1 As shown, as one specific implementation, the number of pairs of the stator magnetic tiles is 4. Preferably, a permanent magnetic material with high magnetic permeability and high residual magnetic density, such as neodymium iron boron, is selected to enhance the magnetic field and improve efficiency.

[0047] In the above embodiment, a closed-loop control system is established between the PWM control part, the motor drive part and the multi-pole DC motor. By detecting the real-time speed and load condition of the motor, the duty cycle of the PWM signal is dynamically adjusted, thereby achieving fine control of the motor speed and torque, ensuring that the motor can operate efficiently and stably under various working conditions.

[0048] As a specific example of the motor at work, when working, as the power of the multi-stage DC motor increases, the voltage input to the motor by the motor control circuit also increases accordingly. In this process, the increment of current is zero or less than the increment of voltage. This has the advantage that by greatly increasing the voltage and controlling the current to not increase or increase slightly, the working heat of the motor can be effectively reduced, and the stability and service life of the motor can be improved.

[0049] The design of multi-pole motors can reduce the operating current because the magnetic field strength is proportional to the number of poles, which reduces the copper and iron losses caused by the current, thereby improving the overall efficiency of the motor; reduced operating current means less resistance heating inside the motor, which helps to reduce temperature rise, extend motor life, and reduce cooling requirements. Multi-pole motors can provide greater torque at low speeds, which makes them very suitable for applications that require high torque but speed is not critical.

[0050] Based on this, the motor proposed in this application was tested and the following test data is provided.

[0051]

[0052] Therefore, the solution provided in the present application can be widely applied to electric tool products such as electric drills, electric hammers, and electric picks. These tools often need to provide high torque at low speeds to cope with drilling or fixing work on hard materials.

[0053] So far, various embodiments of the present application have been described in detail. In order to avoid obscuring the concept of the present application, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed herein.

[0054] Finally, it should be noted that the above is only a preferred embodiment of the present application, and the aforementioned embodiments are only used to illustrate the technical solution of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that it is still possible to modify the technical solutions recorded in the aforementioned embodiments, or to make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not drive the essence of the corresponding technical solutions away from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A motor control circuit, characterized in that: The motor control circuit includes a controller, The controller is integrated with: The rectifier part is used to convert the alternating current into pulsed direct current, making it a variable direct current voltage; The filtering part is used to smooth the pulsed DC after rectification; Voltage stabilization part, ensuring the output voltage is stable; PWM control part, used to generate PWM signal and control the motor speed and direction by changing the duty cycle; Protection circuits, used to protect circuit systems from overload, short circuit and reverse voltage damage; Motor drive, used to control the direction of current, thereby controlling the forward and reverse rotation of the DC motor; Among them, the AC power supply is connected to the input end of the sorting part, the output end of the rectifying part is connected to the two ends of the filtering part, the output end of the filtering part is connected to the input end of the voltage stabilizing part, the output end of the voltage stabilizing part is connected to the power input of the PWM control part, and the output end of the motor drive is used to connect to the DC motor.

2. A motor control circuit according to claim 1, characterized in that: The rectifying part is used to convert the input first voltage into a second voltage, then step down the voltage into the first voltage, and input it to the motor; wherein the first voltage is lower than the second voltage.

3. A motor control circuit according to claim 2, characterized in that: The value of the first voltage is 90V-260V.

4. A motor control circuit according to claim 1, characterized in that: The rectifying part is used for converting an input first voltage into a second voltage and inputting the second voltage to the motor, wherein the first voltage is lower than the second voltage.

5. A motor control circuit according to claim 4, characterized in that: The value of the second voltage is 260V-60V.

6. A motor control circuit and a multi-pole DC motor according to claim 1, characterized in that: The rectifying part is a rectifying bridge, which is composed of four diodes and converts the alternating current into pulse direct current; during the positive half cycle, two diagonal diodes are turned on; during the negative half cycle, the other two diagonal diodes are turned on.

7. A motor control circuit and a multi-pole DC motor according to claim 1, characterized in that: The filtering part is a filtering capacitor; the voltage stabilizing part is a voltage stabilizer or a switching power supply; the PWM control part is a microcontroller or a dedicated integrated circuit; the protection circuit includes overload protection and / or reverse voltage protection; the motor drive is an H-bridge circuit, which is composed of four MOS tubes.

8. A multi-pole DC motor, characterized in that: The motor comprises at least N pairs of stator magnets, wherein N is an even number greater than or equal to 2, so as to form a multi-pole magnetic field; the motor also comprises corresponding rotor windings to achieve efficient power conversion; and the motor works in conjunction with the motor control circuit described in any one of claims 1-7, wherein the PWM control part controls the speed and direction of the motor by precisely adjusting the width of the current pulse, and the motor drive part is responsible for converting the control signal into the actual action of the motor.

9. A multi-pole DC motor according to claim 8, characterized in that: A closed-loop control system is established between the PWM control part, the motor drive part and the multi-pole DC motor. By detecting the real-time speed and load conditions of the motor, the duty cycle of the PWM signal is dynamically adjusted to achieve fine control of the motor speed and torque, ensuring that the motor can operate efficiently and stably under various working conditions.

10. A multi-pole DC motor according to claim 8, characterized in that: As the power of the multi-stage DC motor increases, the voltage input to the motor by the motor control circuit also increases. During this process, the increment of the current is zero or less than the increment of the voltage.

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