Three-phase brushless motor split-phase driving method

Abstract

According to the three-phase brushless motor split-phase driving method, six single-phase brushless motor delay starting operation modules are symmetrically arranged on the two sides of each phase of stator magnetic poles, the distance between the modules is equal to the pole distance of rotor magnetic poles, and the modules are distributed at equal angles according to a specific sequence. The module comprises a parallel Hall and a pull-up resistor, an output signal of the module directly controls an H-bridge power switch, and adjustable dead time and a conduction angle of 50 ns to 10 microseconds are provided through turn-off and turn-on delay control, so that a line segment control commutation mechanism is formed. The system is composed of a three-phase stator winding, a delay starting module and an H-bridge driving circuit. Complex algorithms and hardware are omitted, the cost is reduced, the structure is simplified, commutation can be accurately controlled, the operation stability and efficiency are improved, and the three-phase brushless motor also has redundancy and self-power-generation functions. The method has wide application prospects in the fields of industry, traffic and the like. According to the embodiment verification, the performance is obviously superior to that of a traditional scheme.

Description

Technical Field

[0001] The present invention relates to the technical field of motor drive, and specifically refers to a method for driving a three-phase brushless motor by phase separation. This technology is mainly used to improve the driving efficiency, reduce costs, and simplify the structure of the three-phase brushless motor, while enabling the three-phase brushless motor to have redundancy and self-generation functions. It has broad application prospects in many fields that require the use of three-phase brushless motors and can simultaneously achieve redundancy and self-generation, such as industrial automation, electric vehicles, and aerospace. Background Art

[0002] As an efficient and reliable power device, three-phase brushless motors are widely used in modern industry and daily life. Traditional three-phase brushless motors do not have redundancy and self-generation functions and mostly adopt the six-step commutation method, including 120-degree commutation with two phases energized simultaneously and 60-degree commutation with three phases energized simultaneously. A sensor-equipped three-phase brushless motor usually has one Hall sensor per phase, for a total of three Hall sensors, which sequentially output the position data signals of each dot to the controller.

[0003] However, there are some significant problems with this traditional driving method. Since the controller requires the line segment data signals of two points, namely the accurate starting point turn-on and ending point turn-off, although the Hall sensor itself has a latching function and can emit accurate line segment position signals, affected by the manufacturing error of the rotor magnet, it is difficult for the strongest magnetic poles of the magnet and the stator coil to be evenly distributed on the rotating plane. This results in different lengths of the line segment signals emitted by the Hall sensor, making it difficult for the controller to grasp the ideal commutation timing of the stator coil current.

[0004] To solve this problem, existing technologies often add complex hardware accessories and software algorithms to determine the accurate commutation time of the stator coil current, which belongs to a time control method. This method not only increases the manufacturing cost of the motor but also increases the structural size of the motor, which is not conducive to the miniaturization and integration development of the motor. At the same time, the complex hardware and software systems also increase the failure probability and maintenance difficulty of the motor, reducing the reliability and stability of the motor.

[0005] Therefore, a new method and system for driving a three-phase brushless motor by phase separation are needed, which can overcome the deficiencies of traditional technologies and achieve more accurate and simpler motor drive control. Summary of the Invention

[0006] The present invention aims to solve the above technical problems and provides a method for driving a three-phase brushless motor by phase separation.

[0007] To solve the above technical problems, the technical solution provided by the present invention is: A method for driving a three-phase brushless motor by phase separation, including:

[0008] S1: Two single-phase brushless motor delayed start operation modules are symmetrically arranged on both sides of each phase stator pole, and a total of six modules are arranged for three phases. The module spacing is equal to the pole pitch of the rotor pole, and the modules are installed on the geometric center line of the rotor after the center of the stator pole is aligned with the center of the rotor pole;

[0009] S2: Each module contains two Hall sensors and pull-up resistors connected in parallel, where:

[0010] The positive and negative electrodes of the first Hall and the second Hall are connected in parallel for power supply;

[0011] The second Hall signal output terminal is connected to the positive electrode of the power supply through a pull-up resistor;

[0012] The first Hall and second Hall signal output lines are connected in parallel to form a module output end;

[0013] S3: The high and low level signals output by each module directly control the H-bridge power switch to achieve:

[0014] When the area covered by the rotor S pole of any Hall is more than 80%, the output is low level to cut off the forward current;

[0015] When the second Hall is completely covered by the rotor N pole, it outputs a high level and turns on the reverse current;

[0016] S4: Through the module's turn-off-before-turn-on delay control function, the H-bridge is provided with 50ns-10μs adjustable dead time and conduction angle, forming a segment-controlled commutation mechanism based on four points and one line.

[0017] Furthermore, the six modules are arranged in a forward rotation manner along the circumferential direction and are angularly distributed in the order of A phase first module, A phase second module, B phase first module, B phase second module, C phase first module, and C phase second module, and the installation angle interval between the two modules of each phase is equal to the rotor pole pitch.

[0018] Furthermore, the two modules of each phase are symmetrically arranged on both sides of the stator pole shoe, the connection direction thereof coincides with the radial center line of the stator yoke, and the two Hall sensors are arranged in a straight line, the connection direction of which is consistent with the tangential direction of the rotor rotation.

[0019] Furthermore, the delay control function is implemented in the following manner:

[0020] During the rotor pole switching process, the current conduction module turns off the output signal first, and after the physical spacing arrangement and circuit RC delay, the next module turns on the output signal.

[0021] Furthermore, when the geometric center line of the rotor magnetic pole is aligned with the center line of the stator magnetic pole, the corresponding module is located in the boundary area between adjacent rotor magnetic poles.

[0022] Furthermore, the H-bridge control logic is as follows: when the module outputs a low level, the forward driving MOS transistor is turned off, and when the module outputs a high level, the reverse driving MOS transistor is turned on. Each phase H-bridge is independently controlled by the output signals of two modules corresponding to the same phase.

[0023] A three-phase brushless motor phase-splitting drive system, comprising:

[0024] Three-phase stator windings, with two delay start modules symmetrically arranged on the center line of each phase stator magnetic pole, and the module spacing is equal to the rotor magnetic pole pitch;

[0025] Each module includes two Hall sensors and a pull-up resistor connected in parallel, and the Hall signal output terminal is connected to the H-bridge drive circuit through the pull-up resistor;

[0026] The H-bridge drive circuit switches the direction of the stator winding current in real time according to the Hall signal. Specifically: when the S pole covers any Hall, it outputs a low level to cut off the forward current, and when the N pole covers the second Hall, it outputs a high level to conduct the reverse current. The delay control unit of the module realizes an adjustable dead time of 50 ns - 10 μs through a hardware circuit.

[0027] Furthermore, the Hall sensors are evenly distributed at equal angles according to the rotor magnetic pole pitch. When the center line of the rotor magnetic pole is aligned with the center line of the stator magnetic pole, the corresponding module is located in the adjacent magnetic pole intersection area of the rotor.

[0028] Furthermore, each phase H-bridge is independently configured with a control circuit, and directly responds to the Hall signal to achieve real-time commutation without algorithm processing.

[0029] Furthermore, the delay control unit includes a Hall component and an RC delay circuit arranged with a physical distance, which jointly adjust the dead time and conduction angle.

[0030] The advantages of the present invention compared with the prior art are as follows:

[0031] 1. The present invention eliminates the complex hardware supporting and software algorithms in the traditional driving method, directly controls the current commutation by the Hall signal, reduces the hardware cost and software development cost. At the same time, due to the simplified structure, the production and assembly costs of the motor are also correspondingly reduced.

[0032] 2. Adopting the phase-splitting drive method of six single-phase brushless motor delay start operation modules, it avoids the complex control circuits and algorithms in the traditional method, making the structure of the motor simpler and more compact. This is beneficial to the miniaturization and integrated design of the motor, and is suitable for application scenarios with high space requirements.

[0033] 3. Controlling the H-bridge through the high and low level signals directly output by the Hall sensor can more accurately grasp the current commutation timing of the stator coil. Even if there are manufacturing errors in the rotor magnets, precise commutation control can be achieved through the settings and delay control functions of the module, improving the operating efficiency and stability of the motor.

[0034] 4. The simplified structure and real-time commutation method without algorithm processing reduce the fault points of the system and lower the probability of faults. At the same time, the delay control unit implemented by the hardware circuit has high stability and reliability, further improving the overall reliability of the motor. Brief Description of the Drawings

[0035] Figure 1 It is a planar structure diagram of a three-phase brushless motor phase splitting drive method of the present invention.

[0036] Figure 2 It is a planar wiring diagram of a delay start and operation module of a single-phase brushless motor, which is an accessory of the present invention.

[0037] As shown in the figure: 100, the first Hall; 200, the second Hall; 300, the pull-up resistor. Detailed Embodiment

[0038] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0039] I. Working Principle of the Present Invention:

[0040] Figure 1It is a planar structure diagram of a three-phase brushless motor's phase-separated drive method. Among them, 1 is the first geometric center line of the rotor magnet after the magnetic pole center of the A-phase stator coil is aligned with the magnetic pole center of the rotor; 2 is the first single-phase brushless motor delay start operation module of the A-phase coil. It has a delay function of turning off first and then turning on, which can provide any dead time and conduction angle of the stator coil to the H-bridge board; 3 is the head wire of the A-phase coil; 4 is the tail wire of the A-phase coil; 5 is the center alignment line of the A-phase stator magnetic pole and the rotor magnetic pole; 6 is the second single-phase brushless motor delay start operation module of the A-phase; 7 is the second geometric center line of the rotor magnet after the magnetic pole center of the A-phase stator coil is aligned with the rotor magnet; 8 is the first geometric center line of the rotor magnet after the magnetic pole center of the B-phase stator magnetic pole is aligned with the magnetic pole center of the rotor magnet; 9 is the first single-phase brushless motor delay start operation module of the B-phase; 10 is the head wire of the B-phase stator coil; 11 is the center alignment line of the B-phase stator coil and the rotor magnet; 12 is the tail wire of the B-phase stator coil; 13 is the second single-phase brushless motor delay start operation module of the B-phase; 14 is the second geometric center line of the rotor magnet after the B-phase stator coil is aligned with the rotor magnet's magnetic center line; 15 is the first geometric center line of the rotor magnet after the C-phase stator coil is aligned with the rotor magnet's magnetic center line; 16 is the first single-phase brushless motor delay start operation module of the C-phase stator coil; 17 is the head wire of the C-phase stator coil; 18 is the center alignment line of the C-phase stator coil and the rotor magnet; 19 is the tail wire of the stator coil; 20 is the second single-phase brushless motor delay start operation module of the C-phase stator coil; 21 is the second geometric center line of the C-phase stator coil after being aligned with the rotor magnet's magnetic pole center; 22 is the rotor magnet; 23 is the stator pole shoe; 24 is the stator yoke; 25 is the stator; 26 is the rotor main shaft.

[0041] Figure 2 It is a planar wiring diagram of the delay start operation module of the accessory single-phase brushless motor of the present invention. 100 is the first 41F Hall; 200 is the second 41F Hall, 300 is the pull-up resistor of the Hall. One end is connected to the positive power supply of the Hall, and the other end is connected to the 0 line of the signal output terminal of the second Hall. + is the positive power supply of the first Hall, which is in parallel with the positive pole of the second Hall. - is the negative power supply of the first Hall, which is in parallel with the negative pole of the second Hall. 0 is the signal output line of the second Hall in parallel with the signal output line of the first Hall.

[0042] Three-phase brushless motor phase-splitting drive method, in which two single-phase brushless motor delayed start and operation modules are symmetrically arranged on both sides of each stator pole, and a total of six modules are arranged for three phases. The spacing between these modules is equal to the pole pitch of the rotor poles, and they are installed on the rotor geometric center line after the stator pole center and the rotor pole center are aligned. The six modules are arranged in a forward rotation order in the circumferential direction and are equally angularly distributed in the order of the first module of phase A, the second module of phase A, the first module of phase B, the second module of phase B, the first module of phase C, and the second module of phase C. The installation angle interval between adjacent modules is equal to the rotor pole pitch. The two modules of each phase are symmetrically arranged on both sides of the stator pole shoe, the connection direction thereof coincides with the radial center line of the stator yoke, and the two Hall sensors are arranged in a straight line, and the connection direction is consistent with the rotor rotation tangent direction.

[0043] Each module includes two Hall sensors and a pull-up resistor connected in parallel. The first Hall and the second Hall are supplied with power in parallel with opposite polarities. The signal output terminal of the second Hall is connected to the positive power supply through the pull-up resistor, and the two Hall signal output lines are connected in parallel to form the module output terminal.

[0044] The high and low level signals output by each module directly control the H-bridge power switch. When the covered area of any Hall by the rotor S pole reaches more than 80%, a low level is output to cut off the forward current; when the second Hall is completely covered by the rotor N pole, a high level is output to turn on the reverse current.

[0045] Through the delay control function of closing first and then opening of the module, a 50ns - 10μs adjustable dead time and conduction angle are provided for the H-bridge, forming a line segment control commutation mechanism based on four points in a line. This delay control function is realized by the current conducting module closing the output signal first during the rotor pole switching process, and after the combined action of the physical spacing arrangement and the circuit RC delay, the next module opens the output signal.

[0046] Three-phase brushless motor phase-splitting drive system, including three-phase stator windings, with two delayed start modules symmetrically arranged on the center line of each stator pole, and the module spacing being equal to the rotor pole pitch. Each module includes two Hall sensors and a pull-up resistor connected in parallel, and the Hall signal output terminal is connected to the H-bridge drive circuit through the pull-up resistor. The H-bridge drive circuit switches the current direction of the stator winding in real time according to the Hall signal. When the S pole covers any Hall, a low level is output to cut off the forward current; when the N pole covers the second Hall, a high level is output to conduct the reverse current. The delay control unit of the module realizes a 50ns - 10μs adjustable dead time through a hardware circuit. This delay control unit includes Hall components arranged with physical spacing and an RC delay circuit, which jointly adjust the dead time and conduction angle. Each phase H-bridge is independently configured with a control circuit, directly responding to the Hall signal to achieve real-time commutation without algorithm processing.

[0047] II. Embodiment:

[0048] The working principle of the three-phase brushless motor phase-splitting drive method and system of the present invention is to utilize the real-time position high and low level signals of the rotor magnet and the stator coil emitted by the two single-phase brushless motor delay start and operation modules in each phase, and directly control the switching of the H-bridge to achieve timely commutation of the coil current. It eliminates the complex programs and hardware configurations of the intermediate algorithms, directly controls the current commutation by Hall signals, and forms a phase-splitting drive closed-loop control system with a simple structure.

[0049] Specifically, when the rotor rotates, the relative position between the rotor magnetic pole and the Hall sensor changes. When the S pole of the rotor covers more than 80% of the area of any Hall sensor, the Hall sensor outputs a low level, and this low level signal directly controls the H-bridge to cut off the forward current; when the N pole of the rotor completely covers the second Hall sensor, the Hall sensor outputs a high level, and the high level signal directly controls the H-bridge to connect the reverse current. In this way, the stator magnetic pole conversion generates a repulsive force to push the rotor magnet and at the same time attracts the next rotor magnet to continue rotating.

[0050] The delay control function of the module is realized by the physical spacing arrangement and the circuit RC delay together. During the process of rotor magnetic pole switching, when the previous conducting module first turns off the output signal, after a certain delay, the next module turns on the output signal, so as to provide an adjustable dead time and conduction angle for the H-bridge, realize the line segment control commutation mechanism based on four points in a line, and ensure the stable operation of the motor.

[0051] The above has described the present invention and its implementation manners, and this description is not restrictive. What is shown in the appendix Figure 1 is only one of the implementation manners of the present invention, and the actual structure is not limited thereto. All in all, if those of ordinary skill in the art are inspired by it and, without departing from the purpose of the present invention, design similar structural forms to this technical solution without creative efforts, including redundant and self-generating multi-phase brushless motors and embodiments, they should all fall within the protection scope of the present invention.

Claims

1. A three-phase brushless motor phase-splitting drive method, characterized in that: include: S1: Two single-phase brushless motor delayed start operation modules are symmetrically arranged on both sides of each phase stator pole, and a total of six modules are arranged for three phases. The module spacing is equal to the pole pitch of the rotor pole, and the modules are installed on the geometric center line of the rotor after the center of the stator pole is aligned with the center of the rotor pole; S2: Each module contains two Hall sensors and pull-up resistors connected in parallel, where: The positive and negative electrodes of the first Hall (100) and the second Hall (200) are connected in parallel to supply power; The second Hall signal output terminal is connected to the positive electrode of the power supply via a pull-up resistor (300); The Hall signal output lines of the first Hall (100) and the second Hall (200) are connected in parallel to form a module output end; S3: The high and low level signals output by each module directly control the H-bridge power switch to achieve: When the area covered by the rotor S pole of any Hall is more than 80%, the output is low level to cut off the forward current; When the second Hall is completely covered by the rotor N pole, it outputs a high level and turns on the reverse current; S4: Through the module's turn-off-before-turn-on delay control function, the H-bridge is provided with 50ns-10μs adjustable dead time and conduction angle, forming a segment-controlled commutation mechanism based on four points and one line.

2. The split-phase driving method of a three-phase brushless motor according to claim 1, wherein: The six modules are arranged in a forward rotation manner along the circumferential direction and are distributed at equal angles in the order of A phase first module and A phase second module, B phase first module and B phase second module, C phase first module and C phase second module. The installation angle interval between the two modules of each phase is equal to the rotor pole pitch.

3. A three-phase brushless motor phase splitting drive method according to claim 1, characterized in that: The two modules of each phase are symmetrically arranged on both sides of the stator pole shoe, and the connection direction coincides with the radial center line of the stator yoke. The two Hall sensors are arranged in a straight line, and the connection direction is consistent with the tangential direction of the rotor rotation.

4. A three-phase brushless motor phase-splitting drive method according to claim 1, characterized in that: The delay control function is implemented in the following way: During the rotor pole switching process, the current conduction module first turns off the output signal, and after the physical spacing arrangement and circuit RC delay, the next module turns on the output signal.

5. A three-phase brushless motor phase-splitting drive method according to claim 1, characterized in that: When the geometric center line of the rotor magnetic pole is aligned with the center line of the stator magnetic pole, the corresponding module is located in the boundary area of ​​adjacent rotor magnetic poles.

6. A three-phase brushless motor phase splitting drive method according to claim 1, characterized in that: The H-bridge control logic is: when the module outputs a low level, the forward driving MOS tube is turned off; when the module outputs a high level, the reverse driving MOS tube is turned on; each phase of the H-bridge is independently controlled by the output signals of the two modules of the corresponding phase.

7. A three-phase brushless motor phase splitting drive system, characterized in that: include: Three-phase stator winding, two delayed start modules are symmetrically arranged on the center line of each phase stator pole, and the module spacing is equal to the rotor pole pitch; Each module includes two Hall sensors and a pull-up resistor in parallel, and the Hall signal output end is connected to the H-bridge drive circuit via the pull-up resistor; The H-bridge drive circuit switches the stator winding current direction in real time according to the Hall signal, where: when the S pole covers any Hall, it outputs a low level to cut off the forward current, and when the N pole covers the second Hall, it outputs a high level to turn on the reverse current. The module's delay control unit achieves an adjustable dead time of 50ns-10μs through a hardware circuit.

8. A three-phase brushless motor phase-splitting drive system according to claim 7, characterized in that: The Hall sensors are distributed at equal angles according to the rotor pole pitch. When the rotor pole center line is aligned with the stator pole center line, the corresponding module is located at the junction area of ​​adjacent rotor poles.

9. A three-phase brushless motor phase splitting drive system according to claim 7, characterized in that: Each phase H-bridge is independently configured with a control circuit, which directly responds to the Hall signal to achieve real-time commutation without algorithm processing.

10. A three-phase brushless motor phase-splitting drive system according to claim 7, characterized in that: The delay control unit includes a Hall component and an RC delay circuit arranged with a physical spacing, jointly adjusting the dead time and conduction angle.

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