WO2018054282A1

WO2018054282A1 - Low vibration torque permanent magnet brushless direct current electric motor system

Info

Publication number: WO2018054282A1
Application number: PCT/CN2017/102247
Authority: WO
Inventors: 冯浩
Original assignee: 杭州电子科技大学
Priority date: 2016-09-22
Filing date: 2017-09-19
Publication date: 2018-03-29
Also published as: CN106230209A

Abstract

A low vibration torque permanent magnet brushless direct current electric motor system. The permanent magnet brushless direct current electric motor of the present system is based on a three-phase six-state control mode, and has the two structural forms of a single stator core and a single rotor core, and a double stator sub-core and a double rotor sub-core; when the electric motor is in operation, in addition to the average torque for generating a drive load, the motor can also generate two vibration torques with the same amplitude and 180° electrical angle phase difference, suppressing and offsetting the vibration torque by means of the principle of peak and valley complementarity, and thereby achieving a permanent magnet brushless direct current electric motor with low vibration torque.

Description

Permanent magnet brushless DC motor system with low vibration torque

Technical field

The invention relates to a brushless DC motor, in particular to a permanent magnet brushless DC motor system with low vibration torque.

Background technique

The permanent magnet brushless DC motor is a new type of DC motor developed in these decades. However, the permanent magnet brushless DC motor has a severe vibration torque due to electronic commutation, and the generated vibration torque waveform is shown in Fig. 1. Moreover, the vibration torque amplitude and the rotational speed are as shown in Fig. 2, which is The vibration torque is transmitted to the load through the transmission shaft, thereby generating mechanical vibration and noise of the transmission system.

Summary of the invention

The present invention is directed to the current state of the structure of permanent magnet brushless DC motors of different powers. Based on the existing structures, two low-vibration torque permanent magnet brushless DC motor systems of different structure types are proposed.

Low-vibration torque permanent magnet brushless DC motor system, based on three-phase six-state control mode permanent magnet brushless DC motor, in addition to generating average torque drive load, and can produce two amplitudes of the same, phase difference 180 ° The pulsating torque of the electrical angle is compensated against the pulsating torque by the principle of peak-to-valley complementation, and the low-vibration torque of the permanent magnet brushless DC motor is realized.

The first structure is for a medium and high power permanent magnet brushless DC motor. A permanent magnet brushless DC motor system with low vibration torque of single stator core and single rotor core is proposed, including base, stator core and stator. The winding, the permanent magnet rotor, the rotor position sensing system and the drive controller, the stator core is located on the inner side of the base and fixed to the base; the stator core is provided with a slot for the stator winding, and the electromagnetic core parameters are the same in the stator core winding slot. The X, X' two sets of symmetrical stator windings, each set of three phases, are symmetrically arranged in the stator core slot according to the pole pair number requirement, and can respectively form a Y-shaped or Δ-shaped connection, for three-phase six-state control. In the operation mode, the two sets of X and X' windings are arranged in the stator core with a difference of 30° electrical angle; the permanent magnet rotor is located inside the stator core, the permanent magnet rotor is composed of permanent magnet steel and iron core, and the permanent magnet magnet is fixed to the iron core. The iron core and the rotating shaft are fixed and fixed to the base through the bearing and the end caps at both ends, and can rotate relative to the stator core; the sensing portion of the rotor position sensing system passes through the rotor position sensing system. And the shaft portion to be fixed to the bracket with the rotation of the permanent magnet rotor, a rotor position sensing system may be employed Photoelectric or magnetic induction type, the induction part magnetic steel and the rotor magnetic steel form an electrical angle with each other, and the rotor position sensor receiving part corresponding to each phase winding is spatially aligned with the starting position of each phase winding and mounted on the substrate, The relative position of the base is fixed; the main circuit of the drive controller has two sets of three-phase full-bridge drive circuits, respectively supplying power to the X and X' sets of windings to realize the drive and speed control of the permanent magnet brushless DC motor system.

The first structure of the low vibration torque permanent magnet brushless DC motor is a double stator core and a double rotor core structure; including a base, left and right stator cores, left and right stator windings, left and right permanent magnet rotors, left and right rotor position sensing systems And the drive controller; the left and right stator cores are arranged on the inner side of the base, and are fixed to the base; the stator core is provided with slots for the stator windings, the stator windings are embedded in the winding slots of the stator core, and the electromagnetic parameters of the left and right stator windings are the same, both For three phases, they can form a Y-shaped or Δ-shaped connection at the same time; the left and right permanent magnet rotors are respectively located inside the left and right stator cores, the permanent magnet rotor is composed of a permanent magnet and a rotor core, and the permanent magnets are fixed to the rotor core and the rotor core Fixed with the rotating shaft and fixed to the base through the bearing and the end caps at both ends, and can rotate relative to the stator core; the sensing portion of the rotor position sensing system is fixed with the permanent magnet rotor through the sensing portion bracket of the rotor position sensing system and the rotating shaft Rotating or directly using the permanent magnet rotor itself, the rotor position sensing system is magnetically inductive and mounted on the substrate and machine The relative position is fixed; the main circuit of the drive controller has two sets of three-phase full-bridge drive circuits, and respectively supplies power to the two sets of windings according to the three-phase six-state control mode, thereby realizing driving and speed control of the permanent magnet brushless DC motor system; It actually constitutes a double-motor structure consisting of left and right stators, rotors and position sensors. The two motors have the same structure and electromagnetic parameters, and are offset from each other by an electrical angle in the circumferential space; that is, when the rotor magnets are axially aligned, the stator is The circumferential direction is staggered by an electrical angle; or when the stator winding axes of the stator are aligned in the circumferential direction, the rotor magnetic steel axis is staggered by an electrical angle in the circumferential direction.

Advantageous Effects of Invention: In the present invention, the two sets of stators X and X' are controlled by a rotor position sensing system to drive power to two sets of three-phase windings respectively. For three-phase six-state control mode, stator winding current and permanent magnet rotor Interaction, generating the same average torque driving load in the same direction, the vibration torque generated by the commutation process of the two sets of windings and the vibration torque generated by the motor rotor magnet width coefficient less than 1 are the same, and the two sets of stators The winding current is phase-inverted with the vibration torque generated by the interaction of the permanent magnet rotor, so that the peak-to-valley complementation is suppressed, thereby realizing the low vibration torque characteristic of the permanent magnet brushless DC motor. The ideal state is due to the symmetry of the electromagnetic parameters of the two sets of windings. The symmetrical parameters of the driver circuit produce the same amplitude of the vibration torque, and the phase is opposite to each other by 180°. The vibration torque generated by the flow commutation process enables complete complementary suppression. Actually, due to the asymmetry of the three-phase electromagnetic parameters, although the vibration torque can not be completely eliminated, the vibration torque can be significantly reduced.

DRAWINGS

1 is a vibration torque waveform generated according to a three-phase six-state control method;

Figure 2 is the relationship between commutation torque ripple and speed

Figure 3 is a schematic view showing the peak-valley complementary suppression reducing the vibration torque;

Figure 4 is a structural diagram of a brushless DC motor with low vibration torque;

5 is a schematic structural view of a stator winding of a brushless DC motor with low vibration torque;

Figure 6 is a schematic diagram of the position sensor;

Figure 7-1 is a schematic view showing the structure of the stator winding of the second type of low power and low vibration torque brushless DC motor;

Figure 7-2 is a structural diagram of a second type of low power low vibration torque brushless DC motor;

Figure 8-1 is a schematic view showing the relative position of the stator and rotor of the left stator winding of the second type of low power and low vibration torque brushless DC motor;

Figure 8-2 is a schematic diagram of the relative position of the stator and rotor of the right stator winding of the second type of low power and low vibration torque brushless DC motor.

detailed description

As shown in FIG. 3, FIG. 4, FIG. 5 and FIG. 6, a single-stator, single-rotor structure low-vibration torque brushless DC motor system includes: rotor position sensing system cover 1, rear bearing 2, and rotor Position sensor sensing portion holder 3, rotor position sensor sensing portion magnet 4, rotor position sensor receiving portion 5 corresponding to winding X, rotor position sensor receiving portion 5' corresponding to winding X', rear end cover 6, stator core 7 , permanent magnet rotor magnet 8, stator winding 9, another set of stator windings 9', rotor core 10, front bearing 11, shaft 12, front end cover 13, base 14;

The stator core 7 is located on the inner side of the base 14 and fixed to the base; the stator core is provided with a slot for the stator winding, and the stator core winding slot has 9, 9' two sets of symmetric stator windings having the same electromagnetic parameters, each group All of them are three-phase, which are symmetrically arranged in the stator core slot according to the requirements of the pole pair number. The arrangement of the 9th and 9th sets of windings in the stator core is 30° electrical angle difference, and can respectively form a Y-shaped or Δ-shaped connection; The permanent magnet rotor is located inside the stator core, and the permanent magnet rotor is composed of a permanent magnet magnet 8 and a rotor core 10. The permanent magnet magnet 8 is fixed to the core 10, and the core 10 is fixed to the rotating shaft 12 and passes through the front and

rear bearings

2 and 11 and the ends of the ends. The

covers

6 and 13 are fixed to the base 14 and the permanent magnet rotor is rotatable relative to the stator core; the sensing portion 4 of the rotor position sensing system passes through the sensing portion bracket 3 and the rotating shaft 12 of the rotor position sensing system Fixed, with the permanent magnet rotor rotating, the sensing portion of the magnetic steel 4 and the rotor magnet 8 position mutually form an electrical angle, and the rotor position sensor receiving portions 5 and 5' corresponding to the respective phase windings spatially and with each phase winding The starting position is aligned on the base and fixed on one side end cover; the rotor position sensing system is externally provided with a rotor position sensing system cover 1;

As shown in Fig. 3, the two sets of windings of the stator X and X' are powered by the rotor position sensing system to drive the two sets of three-phase windings. For the three-phase six-state control mode, the stator winding current interacts with the permanent magnet rotor to generate The average torque driving load in the same direction is the same as the vibration torque generated by the winding current commutation process and the vibration torque generated by the motor rotor magnet width coefficient less than 1 and the two sets of stator windings and permanent magnet rotors are mutually The phase of the vibration torque generated by the current commutation is reversed, so that the peak-to-valley complementation is suppressed, and the low-vibration torque characteristic of the permanent magnet brushless DC motor is realized.

The second structure is for a low-power permanent magnet brushless DC motor, which is mostly a multi-pole flat structure as shown in Fig. 7. For this reason, a low-vibration torque of a double stator core and a double-rotor core is proposed. The permanent magnet brushless DC motor system comprises a base, a left and right stator core, left and right stator windings, left and right permanent magnet rotors, left and right rotor position sensing systems and a drive controller. The left and right stator cores are arranged on the inner side of the base and are fixed to the base; the stator core is provided with a slot for the stator winding, and the stator winding is embedded in the winding slot of the stator core, and the electromagnetic parameters of the left and right stator windings are the same, all of which are three-phase. At the same time, they form a Y-shaped or Δ-shaped connection respectively; the left and right permanent magnet rotors are respectively located inside the left and right stator cores, the permanent magnet rotor is composed of permanent magnet steel and iron core, the permanent magnet magnetic steel is fixed to the iron core, the iron core and the rotating shaft are fixed and pass the bearing and two The end cover of the end is fixed to the base and can rotate relative to the stator core; the sensing part of the rotor position sensing system is fixed by the sensing part bracket of the rotor position sensing system and the rotating shaft to rotate with the permanent magnet rotor, and the permanent magnet can also be directly used. The rotor itself is replaced (in this case, the structure), the rotor position sensing system adopts a magnetic induction type, and the sensing element is mounted on the substrate and fixed relative to the base; the main circuit of the drive controller has two sets of three-phase full-bridge driving circuits. The two sets of windings are respectively supplied with power in three phases and six states to realize driving and speed control of the permanent magnet brushless DC motor system. The two motors are composed of left and right stators, rotors and position sensors. The two motors have the same structure and electromagnetic parameters, and are offset from each other by an electrical angle in the circumferential space.

As shown in Figure 7-1, Figure 7-2, Figure 8-1, and Figure 8-2, a low-vibration torque brushless DC motor system with dual stator and dual rotor structure includes: frame 1-1 Left and right stator core 2-1, left and right stator windings 3-1, left and right rotor permanent magnets 4-1, left and right rotor cores 5-1, rotating shaft 6-1, left and right end covers 7-1, left and right position sensor substrates 8- 1. Left and right bearings 9-1.

The left and right stator cores are arranged on the inner side of the base 1-1, and are fixed to the base; the left and right stator cores 2-1 are provided with slots for the stator windings, and the left and right stator windings 3-1 are embedded in the winding slots of the stator core. The left and right stator windings have the same electromagnetic parameters, all of which are three-phase, and respectively form a Y-shaped or Δ-shaped connection; the left and right permanent magnet rotors are respectively located inside the left and right stator cores, and the permanent magnet rotor is composed of permanent magnet steel and rotor core, and the left and right rotors are forever The magnetic magnetic steel 4-1 is fixed to the left and right rotor cores 5-1, and the rotor core is fixed to the rotating shaft and fixed to the base through the bearing and the end caps at both ends, and can rotate relative to the stator core; the sensing portion of the rotor position sensing system The sensing part bracket and the rotating shaft fixed by the rotor position sensing system are rotated with the permanent magnet rotor, and can also be directly replaced by the permanent magnet rotor itself. The rotor position sensing system adopts a magnetic induction type, and the sensing element is mounted on the substrate opposite to the base. The position is fixed; the main circuit of the drive controller has two sets of three-phase full-bridge drive circuits, which respectively supply power to the two sets of windings to realize the driving and adjustment of the permanent magnet brushless DC motor system. Control. The two motors on the left and the right have the same structure and electromagnetic parameters, and are offset from each other by an electrical angle in the circumferential space.

When the left and right stator windings are controlled by the rotor position sensing system to drive the two sets of three-phase windings according to the three-phase six-state control mode, respectively, the same average torque driving load is generated on the rotor, and two amplitudes are generated simultaneously. Similarly, the pulsating torque with a phase difference of 180° electrical angle is suppressed by the cancellation of the actual pulsating torque by the complementary principle of the peaks and valleys, thereby realizing the low vibration torque characteristic of the permanent magnet brushless DC motor.

Claims

A permanent magnet brushless DC motor system with low vibration torque, characterized in that: a permanent magnet brushless DC motor based on a three-phase six-state control mode, in addition to generating an average torque driving load, and capable of generating two amplitudes of the same, The pulsating torque with a phase difference of 180° electrical angle compensates the pulsating torque by the principle of peak-to-valley complementation, and achieves low vibration torque of the permanent magnet brushless DC motor.
The low vibration torque permanent magnet brushless DC motor system according to claim 1, characterized by: a single stator core and a single rotor core structure; including a base, a stator core, a stator winding, a permanent magnet rotor, and a rotor position The sensing system and the driving controller; the stator core is located on the inner side of the base and fixed to the base; the stator core is provided with a slot for the stator winding, and the X, X' two-group symmetric stator with the same electromagnetic parameters is placed in the stator core winding slot. The windings are three-phase in each group. They are symmetrically arranged in the stator core slot according to the pole-number requirements. The two sets of X and X' windings are arranged in the stator core with an electrical angle of 30°, and they respectively form a Y-shape or a Δ. The permanent magnet rotor is located inside the stator core, the permanent magnet rotor is composed of permanent magnet steel and iron core, and the permanent magnet magnet is fixed to the rotor core. The rotor core is fixed to the rotating shaft and fixed to the base through the bearing and the end caps at both ends. Rotating motion with respect to the stator core; the rotor position sensing system adopts a magnetic induction type, and the sensing portion of the rotor position sensing system passes through the sensing portion bracket and the rotating shaft of the rotor position sensing system As the permanent magnet rotor rotates, the induction magnet and the rotor magnet form an electrical angle with each other, and the rotor position sensor receiving portion corresponding to each phase winding is spatially aligned with the starting position of each phase winding and mounted on the substrate. And the position of the base is relatively fixed; the main circuit of the drive controller has two sets of three-phase full-bridge drive circuits, and the two sets of six-state control modes are respectively supplied to the X and X' sets of windings to realize the permanent magnet brushless DC Motor system drive and speed control.
A low vibration torque permanent magnet brushless DC motor system according to claim 2, wherein said rotor position sensing system is of a photoelectric type.
The low vibration torque permanent magnet brushless DC motor system according to claim 1, characterized in that it is a double stator core and a double rotor core structure; and comprises a base, a left and right stator core, left and right stator windings, and left and right permanent magnet rotors. The left and right rotor position sensing systems and the drive controller; the left and right stator cores are arranged on the inner side of the base and are fixed to the base; the stator core is provided with slots for the stator windings, and the stator windings are embedded in the winding slots of the stator core, left and right The stator windings have the same electromagnetic parameters, all of which are three-phase, and can form Y-shaped or Δ-shaped connections at the same time; the left and right permanent magnet rotors are respectively located inside the left and right stator cores, and the permanent magnet rotor is composed of permanent magnet steel and rotor core, permanent magnet steel Fixed to the rotor core, The rotor core is fixed to the rotating shaft and fixed to the base through the bearing and the end caps at both ends, and can rotate relative to the stator core; the sensing portion of the rotor position sensing system is fixed by the sensing portion bracket of the rotor position sensing system and the rotating shaft. The magnetic rotor rotates or directly replaces the permanent magnet rotor itself. The rotor position sensing system adopts magnetic induction type and is mounted on the substrate and fixed relative to the base. The main circuit of the drive controller has two sets of three-phase full-bridge drive circuits. According to the three-phase six-state control mode, the two sets of windings are respectively supplied with power to realize the driving and speed control of the permanent magnet brushless DC motor system; the actual two-motor structure consisting of left and right stators, rotors and position sensors, two motors Regardless of the structure or the electromagnetic parameters, they are offset from each other by an electrical angle in the circumferential space; that is, when the rotor magnets are axially aligned, the stator is staggered by an electrical angle in the circumferential direction; or when the stator winding axes are aligned in the circumferential direction. Then, the axis of the rotor magnet steel is staggered by an electrical angle in the circumferential direction.