WO2024103280A1

WO2024103280A1 - Hybrid-winding permanent magnet reluctance brushless motor and driving method therefor

Info

Publication number: WO2024103280A1
Application number: PCT/CN2022/132183
Authority: WO
Inventors: 刘则锋
Original assignee: 成都倒立摆科技有限公司
Priority date: 2022-11-16
Filing date: 2022-11-16
Publication date: 2024-05-23

Abstract

Provided are a hybrid-winding permanent magnet reluctance brushless motor and a driving method therefor. The hybrid-winding permanent magnet reluctance brushless motor comprises a rotor outer frame (10), a rotor core (20), a plurality of rotor reluctance poles (30), permanent magnets (40), a stator shaft (50), a plurality of stator cores (60), and three winding bodies, wherein one of two permanent magnets (40) is an S-pole permanent magnet, and the other is an N-pole permanent magnet; the three winding bodies have a common winding connection point; each winding body comprises three windings, one of the windings is an independent winding, the other two windings are connected in series, and the series windings are distributed on two sides of the independent winding; and the series windings in each winding body are in phase and are connected end to end, and the independent winding is out of phase with and connected in parallel to the inputs and outputs of the series windings. Each phase of the winding bodies is in both series connection and parallel connection, so that the torque and the speed are both considered; due to the presence of the rotor reluctance poles (30), the torque of the motor is larger, the requirement for the permanent magnets (40) is lower, and automatic attachment is achieved due to the centrifugal force of a rotor.

Description

A hybrid winding permanent magnet reluctance brushless motor and a driving method thereof

Technical Field

The present invention belongs to the technical field of motors, and in particular relates to a hybrid winding permanent magnet reluctance brushless motor and a driving method thereof.

Background technique

The brushless motor is a new type of DC motor. Its working principle is to use electronic switching devices to replace the old contact commutator and brushes, so that the motor has higher reliability and can also reduce mechanical noise.

Various intelligent power devices on the current market have higher demands on motors, which require the motor system of the power source to be smaller in size, higher in power density and higher in speed.

Therefore, it is necessary to design a new brushless motor.

Summary of the invention

The object of the present invention is to provide a hybrid winding permanent magnet reluctance brushless motor and a driving method thereof in which each phase of the winding body is connected in series and has a greater torque at low speed.

The present invention provides a hybrid winding permanent magnet reluctance brushless motor, which comprises a rotor outer frame, a rotor core located in the rotor outer frame, a plurality of rotor reluctance poles located in the rotor core, two permanent magnets located between adjacent rotor reluctance poles, a stator shaft located in the rotor outer frame, a plurality of stator cores fixed on the stator shaft and arranged corresponding to the permanent magnets, and three winding bodies wound on the plurality of stator cores; wherein one of the two permanent magnets is an S-pole permanent magnet and the other is an N-pole permanent magnet; the three winding bodies have a common connection point for windings; each winding body comprises three windings, wherein one winding is an independent winding and the other two windings are connected in series, and the series windings are distributed on both sides of the independent winding; the series windings in each winding body are in phase and connected end to end, and the independent winding is connected in parallel with the input and output of the series winding in anti-phase.

Furthermore, the permanent magnets are distributed on both sides of the rotor reluctance poles, and the magnetic poles of the permanent magnets on both sides of each rotor reluctance pole are the same, and the magnetic poles of the permanent magnets outside two adjacent rotor reluctance poles are different.

Furthermore, the permanent magnets on both sides of each rotor reluctance pole are arranged in a V shape.

Furthermore, two sides of each permanent magnet group are closed.

Furthermore, there are gaps between adjacent groups of permanent magnets, and there are slots between adjacent rotor reluctance poles.

Furthermore, the three winding bodies are respectively an A-phase winding body, a B-phase winding body and a C-phase winding body, wherein the A-phase winding body includes an A-phase first sub-winding, an A-phase independent winding and an A-phase second sub-winding, the A-phase first sub-winding and the A-phase second sub-winding are connected in series and have the same direction, and the A-phase first sub-winding and the A-phase second sub-winding are connected in series and connected in parallel with the A-phase independent winding; wherein the B-phase winding body includes a B-phase first sub-winding, a B-phase independent winding and a B-phase second sub-winding, the B-phase first sub-winding and the B-phase second sub-winding are connected in series and have the same direction, and the A-phase first sub-winding and the A-phase second sub-winding are connected in series and connected in parallel with the A-phase independent winding; The direction is the same, the first sub-winding of phase B and the second sub-winding of phase B are connected in series, and the head and tail of the independent winding are connected in parallel with the independent winding of phase B; wherein the C-phase winding body includes the first sub-winding of phase C, the independent winding of phase C and the second sub-winding of phase C, the first sub-winding of phase C and the second sub-winding of phase C are connected in series and have the same direction, the first sub-winding of phase C and the second sub-winding of phase C are connected in series, and the head and tail of the independent winding are connected in parallel with the independent winding of phase C; one end of all windings are connected together to form a common connection point of windings, and the other ends are respectively connected to the three input phases of the brushless motor.

Furthermore, the number of turns of the independent winding is the sum of the number of turns of the corresponding two series windings.

Furthermore, it also includes a plurality of stator slots connected to the stator shaft, and the stator core is fixed in the corresponding stator slots.

Further, the number of the stator slots is 9 or an integer multiple of 9, and the number of the rotor reluctance poles is 8 and 10 or an integer multiple of 8 and 10 which is the same as the number of the stator slots.

The present invention also provides a driving method for a hybrid winding permanent magnet reluctance brushless motor, and the specific method is as follows: when the winding generates electromagnetic force, it simultaneously attracts the permanent magnet and the magnetically conductive rotor reluctance pole, generates greater pulling force, and increases torque.

The present invention adopts the placement of composite winding bodies and permanent magnets, and each phase of the winding body is both in series and in parallel, so that torque and speed are taken into account; the existence of the rotor reluctance pole makes the motor torque greater, and the requirement for permanent magnets is smaller. The centrifugal force of the rotor automatically fits the characteristic, and the higher the rotor speed, the more stable it tends to be; the present invention can obtain greater torque at low speed, and the current of the motor of the present invention is smaller when it is locked at startup or at low speed. In addition, it is easier to achieve high speed, maintain low-speed torque while taking into account higher speed, and is more stable at high speed, and has the advantages of greater power density at the same volume.

Based on the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more aware of the above and other objects, advantages and features of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

FIG1 is a schematic structural diagram of a hybrid winding permanent magnet reluctance brushless motor used in an embodiment of the present invention;

FIG2 is a schematic diagram of a rotor core punching sheet for a hybrid winding permanent magnet reluctance brushless motor according to an embodiment of the present invention;

FIG. 3 is a simplified schematic diagram of a winding body of a hybrid winding permanent magnet reluctance brushless motor according to an embodiment of the present invention.

FIG. 4 is a schematic structural diagram of a permanent magnet with two ends closed in a hybrid winding permanent magnet reluctance brushless motor according to an embodiment of the present invention.

Detailed ways

The present invention discloses a hybrid winding permanent magnet reluctance brushless motor, as shown in Figures 1 to 3, which includes a rotor outer frame 10, a rotor core 20 located in the rotor outer frame 10, a plurality of rotor reluctance poles 30 located in the rotor core 20 and having a magnetic conductivity function, two permanent magnets 40 located between adjacent rotor reluctance poles 30, a stator shaft 50 located in the rotor outer frame 10, a plurality of stator slots 51 connected to the stator shaft 50, a plurality of stator cores 60 fixed on the stator shaft 50 and located in the stator slots 51, and three winding bodies wound on the stator core 60; wherein the three winding bodies have a common winding connection point O, each winding body includes three windings, one of which is an independent winding, and the other two windings are connected in series, and the series windings are distributed on both sides of the independent windings; the series windings in each winding body are in phase and connected head to tail, and the independent winding is connected in parallel with the input and output of the series winding in anti-phase. The rotor core 20 is formed by stacking magnetic soft magnetic material punching sheets, such as silicon steel sheets.

The number of the permanent magnets 40 is a multiple of 2. In this embodiment, the number of the permanent magnets 40 is 16.

The permanent magnets 40 are distributed on both sides of the rotor reluctance poles 30, and the magnetic poles of the permanent magnets 40 on both sides of each rotor reluctance pole 30 are the same (that is, they are all S-pole permanent magnets or N-pole permanent magnets), the magnetic poles of the permanent magnets on the outside of two adjacent rotor reluctance poles 30 are different (that is, one is an S-pole permanent magnet and the other is an N-pole permanent magnet), and the permanent magnets on both sides of each rotor reluctance pole 30 are arranged in a V shape.

The two sides of each permanent magnet group can be closed (as shown in Figure 4) to increase the strength of the rotor core 20; the permanent magnets 40 are installed in a V-shape, and there is a gap 41 between adjacent permanent magnet groups; there is a slot 31 between adjacent rotor reluctance poles 30, which is used to block the direct magnetic lines of force between the S-pole permanent magnet and the N-pole permanent magnet of each permanent magnet group.

The number of rotor reluctance poles 30 is equal to half the number of permanent magnets 40 .

The motor relies on the forces induced by the permanent magnets 40 and the rotor reluctance poles 30 to act on the rotor core 20 to perform relative rotational motion, and has the advantages of large torque, small current and high speed.

The number of stator slots 51 is 9 or an integer multiple of 9, and the number of rotor reluctance poles 30 is 8 and 10 or an integer multiple of 8 and 10. One end of the stator core 60 is fixed on the stator shaft 50 , and the other end of the stator core 60 is arranged corresponding to the permanent magnet 40 .

There are nine stator cores 60 , each of which is wound with a winding; and each stator core 60 is located between adjacent groups of permanent magnets.

Each winding body includes three windings, one of which is an independent winding and the other two are connected in series. Since each winding body needs to be composed of at least three windings, in a multi-winding three-phase brushless motor, the number of stator slot poles is at least 9 times n, where n is an integer greater than 1.

The three winding bodies are respectively an A-phase winding body, a B-phase winding body and a C-phase winding body. The A-phase winding body includes the A-phase first sub-winding LA1, the A-phase independent winding LA and the A-phase second sub-winding LA2, the A-phase first sub-winding LA1 and the A-phase second sub-winding LA2 are connected in series and in the same direction, and the A-phase first sub-winding LA1 and the A-phase second sub-winding LA2 are connected in series and connected in parallel with the A-phase independent winding LA at the head and tail; the B-phase winding body includes the B-phase first sub-winding LB1, the B-phase independent winding LB and the B-phase second sub-winding LB2, and the B-phase first sub-winding LB1 and the B-phase second sub-winding LB2 are connected in series and connected in parallel with the B-phase independent winding LB at the head and tail; the C-phase winding body includes the C-phase first sub-winding LC1, the C-phase independent winding LC and the C-phase second sub-winding LC2, the C-phase first sub-winding LC1 and the C-phase second sub-winding LC2 are connected in series and in the same direction, and the C-phase first sub-winding LC1 and the C-phase second sub-winding LC2 are connected in series and connected in parallel with the C-phase independent winding LC at the head and tail.

One end of all windings is connected together to form a common connection point O of the windings, and the other end is connected to the three input phases of the brushless motor respectively.

The three windings of each winding body are arranged continuously, the independent winding (i.e., the first independent winding LA of phase A, the first independent winding LB of phase B, and the first independent winding LC of phase C) is located in the middle, and the series windings are distributed on both sides of the independent windings; the series windings in each winding body are in phase and connected end to end, and the independent winding is connected in anti-phase parallel to the series winding input and output.

The number of turns of the independent winding is the sum of the number of turns of the two series windings; the output ends of the A-phase winding body, the B-phase winding body and the C-phase winding body are connected together and are the common connection point O of the windings, forming a star connection.

Two adjacent permanent magnets 40 of the same polarity are arranged in a V shape to form a reluctance pole. When the winding generates electromagnetic force, it can simultaneously attract the permanent magnet 40 and the rotor reluctance pole 30 to generate a greater pulling force, thereby increasing the torque.

The present invention also discloses a driving method of a hybrid winding permanent magnet reluctance brushless motor, comprising the following steps:

For the rotor part, when the winding generates electromagnetic force, it can simultaneously attract the permanent magnet 40 and the magnetically conductive rotor reluctance pole 30 to generate a greater pulling force, thereby increasing the torque.

For the winding part, the motor of the present invention is composed of multiple windings and permanent magnets 40, so it is necessary to ensure that more copper wire is wound around each winding to obtain greater torque. Since the winding and the rotor magnetic resistance pole 30 will move relative to each other, a gradual in and out movement will occur, which will generate an induced current, and the induced current will generate harmful circulating current due to the existence of the potential difference between the head and tail of a phase winding. The best way to eliminate this circulating current is to connect multiple windings of one phase in series, but this will result in only one choice between low-speed torque and high speed. If the head and tail windings of one phase are connected in series and the middle winding is connected in parallel, this contradiction can be solved.

The present invention is suitable for multi-pole and multi-slot-pole brushless motors and requires only a smaller current when the same low-speed torque output is achieved.

The present invention is suitable for the permanent magnet series number of: (9 plus 1 or minus 1) multiplied by n, where n is a multiple of the number of slot poles.

The present invention is not only suitable for outer rotor permanent magnet brushless motors, but also for inner rotor brushless motors; a phase sensor may be used to drive the motor of the present invention, or a phase sensor may not be used; at high speeds, the permanent magnets and the rotor core automatically adhere to the rotor outer frame due to centrifugal force, and are therefore more stable; the temperature-sensitive permanent magnets are located on the periphery of the motor of the present invention, and the heat dissipation conditions are better than those of the traditional magnetic resistance and permanent magnet hybrid inner rotor.

At this point, those skilled in the art should recognize that, although multiple exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications that conform to the principles of the present invention can still be directly determined or derived based on the content disclosed in the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all these other variations or modifications.

Claims

A hybrid winding permanent magnet reluctance brushless motor, characterized in that it comprises a rotor outer frame (10), a rotor core (20) located in the rotor outer frame (10), a plurality of rotor reluctance poles (30) located in the rotor core (20), two permanent magnets (40) located between adjacent rotor reluctance poles (30), a stator shaft (50) located in the rotor outer frame (10), a plurality of stator cores (60) fixed on the stator shaft (50) and arranged corresponding to the permanent magnets (40), and three winding bodies wound on the plurality of stator cores (60); wherein one of the two permanent magnets (40) is an S-pole permanent magnet and the other is an N-pole permanent magnet; the three winding bodies have a common connection point for windings; each winding body comprises three windings, wherein one winding is an independent winding and the other two windings are connected in series, and the series windings are distributed on both sides of the independent winding; the series windings in each winding body are in phase and connected end to end, and the independent winding is connected in parallel with the input and output of the series winding in anti-phase.
The hybrid winding permanent magnet reluctance brushless motor according to claim 1 is characterized in that the permanent magnets (40) are distributed on both sides of the rotor reluctance poles (30), and the magnetic poles of the permanent magnets (40) located on both sides of each rotor reluctance pole (30) are the same, and the magnetic poles of the permanent magnets on the outside of two adjacent rotor reluctance poles (30) are different.
The hybrid winding permanent magnet reluctance brushless motor according to claim 1 is characterized in that the permanent magnets on both sides of each rotor reluctance pole (30) are arranged in a V shape.
The hybrid winding permanent magnet reluctance brushless motor according to claim 1 is characterized in that both sides of each permanent magnet group are closed.
The hybrid winding permanent magnet reluctance brushless motor according to claim 1 is characterized in that there are gaps between adjacent groups of permanent magnets and there are notches between adjacent rotor reluctance poles.
The hybrid winding permanent magnet reluctance brushless motor according to claim 1 is characterized in that the three winding bodies are respectively an A-phase winding body, a B-phase winding body and a C-phase winding body, wherein the A-phase winding body includes an A-phase first sub-winding, an A-phase independent winding and an A-phase second sub-winding, the A-phase first sub-winding and the A-phase second sub-winding are connected in series and in the same direction, and the A-phase first sub-winding The winding and the second sub-winding of phase A are connected in series, and then the ends are connected in parallel with the independent winding of phase A; wherein the winding body of phase B includes the first sub-winding of phase B, the independent winding of phase B and the second sub-winding of phase B, the first sub-winding of phase B and the second sub-winding of phase B are connected in series and in the same direction, and the first sub-winding of phase B and the second sub-winding of phase B are connected in series and then the ends are connected in parallel with the independent winding of phase B; wherein the winding body of phase C includes the first sub-winding of phase C, the independent winding of phase C and the second sub-winding of phase C, the first sub-winding of phase C and the second sub-winding of phase C are connected in series and in the same direction, and the first sub-winding of phase C and the second sub-winding of phase C are connected in series and then the ends are connected in parallel with the independent winding of phase C, and one end of all windings are connected together to form a common connection point of windings, and the other end is respectively connected to the three input phases of the brushless motor.
The hybrid winding permanent magnet reluctance brushless motor according to claim 1 or 6 is characterized in that the number of turns of the independent winding is the sum of the number of turns of the corresponding two series windings.
The hybrid winding permanent magnet reluctance brushless motor according to claim 1 is characterized in that it also includes a plurality of stator slots connected to the stator shaft (50), and the stator core is fixed in the corresponding stator slots.
The hybrid winding permanent magnet reluctance brushless motor according to claim 6 is characterized in that the number of stator slots is 9 or an integer multiple of 9, and the number of rotor reluctance poles is 8 and 10 or 8 and 10 which are the same as the integer multiples of the stator slots.
The driving method of the hybrid winding permanent magnet reluctance brushless motor according to any one of claims 1 to 9 is characterized in that the specific method is as follows:

When the winding generates electromagnetic force, it simultaneously attracts the permanent magnet and the magnetically conductive rotor reluctance pole, generating greater pulling force and increasing torque.