CN110601474A - Radial magnetic field composite flux switching motor - Google Patents

Abstract

The invention relates to the field of motor design, and discloses a radial magnetic field composite flux switching motor, which includes a fixed shaft (6), a rotating shaft (5) coaxially connected with the fixed shaft, an inner rotor (4) surrounding the rotating shaft, The inner stator (3) surrounding the inner rotor, the bearing (23) surrounding the inner stator, the outer stator (2) surrounding the bearing, the outer rotor (1) surrounding the outer stator; between the outer stator and the outer rotor and between the inner stator and the inner Air gaps are provided between the rotors; both the inner rotor and the outer rotor are fixedly connected to the rotating shaft, the inner stator is fixedly connected to the fixed shaft, and the radially inner and outer sides of the bearing (23) are respectively connected to the outer diameter of the inner stator and the inner diameter of the outer stator. On the premise of improving the operating reliability of the permanent magnet and avoiding irreversible demagnetization of the permanent magnet due to weak magnetic speed regulation and high temperature, the present invention satisfies the requirements of the drive motor for low-speed, high-torque operation and wide speed regulation range.

Description

Radial Field Compound Flux Switching Motor

technical field

The invention relates to the field of motor design, in particular to a radial magnetic field compound flux switching motor.

Background technique

In recent years, the flux-switching permanent magnet motor (FSPM for short) has been extensively studied due to its high torque density and high efficiency. Motor reliability and dynamic running performance. However, due to the inherent characteristics of permanent magnets, the air-gap magnetic field of the FSPM motor remains basically constant during operation. During electric operation, the excitation control of the FSPM motor is difficult and the speed regulation range is limited. Therefore, how to realize the limited adjustment and control of the magnetic field and widen its speed regulation range is one of the difficult problems to be solved for FSPM motors. In this regard, scholars have conducted research on hybrid excitation FSPM motors. In addition to permanent magnets on the stator, excitation windings are also set to realize the dual excitation source hybrid excitation method, which can improve the magnetic field adjustment ability and broaden the speed operating range. However, in this motor structure, there are permanent magnets and two sets of windings (field winding and armature winding) in the stator at the same time. On the one hand, the saturation degree of the magnetic circuit is high; Torque output capability; and because the heat source is located in the stator, it is easy to cause the temperature of the stator winding and the permanent magnet to rise too high, resulting in damage to the winding insulation and irreversible demagnetization of the permanent magnet.

Contents of the invention

Purpose of the invention: Aiming at the problems existing in the prior art, the present invention provides a radial magnetic field composite flux switching motor, which can improve the operation reliability of permanent magnets and avoid irreversible demagnetization of permanent magnets caused by weak magnetic speed regulation and high temperature. Under the premise, it meets the requirements of low-speed, high-torque and wide speed range operation of the drive motor.

Technical solution: The present invention provides a radial magnetic field composite flux switching motor, which includes a fixed shaft, a rotating shaft coaxially connected with the fixed shaft, an inner rotor surrounding the rotating shaft, and an inner stator surrounding the inner rotor. stator, a bearing surrounding the inner stator, an outer stator surrounding the bearing, an outer rotor surrounding the outer stator; between the outer stator and the outer rotor and between the inner stator and the inner rotor Both are provided with an air gap; both the inner rotor and the outer rotor are fixedly connected to the rotating shaft, the inner stator is fixedly connected to the fixed shaft, and the inner and outer sides of the radial direction of the bearing are respectively connected to the outer diameter of the inner stator. Connect with the inner diameter of the outer stator.

Further, the opposite side of the outer rotor and the outer stator and the opposite side of the inner rotor and the inner stator are provided with salient pole teeth, and the salient pole teeth of the outer rotor and the inner rotor are There is no winding, the salient pole teeth of the outer stator are provided with outer armature windings and permanent magnets, and the salient pole teeth of the inner stator are provided with inner armature windings.

Preferably, the number of salient pole teeth of the outer stator is P _so , the outer armature winding is composed of symmetrically distributed P _so coils sleeved on the salient pole teeth of the outer stator, and the outer armature The winding is an m -phase concentrated winding, satisfying P _so =2 k ₁ m , where k ₁ is a positive integer; the number of salient pole teeth of the outer rotor is P _ro , satisfying P _ro = P _so ±2N ₁ , where N ₁ is a positive integer.

Preferably, the number of salient pole teeth of the inner stator is P _si , the inner armature winding is composed of symmetrically distributed P _si coils sleeved on the salient pole teeth of the inner stator, and the inner armature The winding is an n -phase concentrated winding, satisfying P _si =2 k ₂ n , where k ₂ is a positive integer; the number of salient pole teeth of the inner rotor is P _ri , satisfying P _ri = P _si ±2N ₂ , where N ₂ is a positive integer.

Preferably, the permanent magnets are tangentially alternately magnetized permanent magnets.

Preferably, the radially inner edge of the inner rotor yoke is fixed on the rotating shaft.

Preferably, the radially outer edge of the outer rotor yoke core is fixedly connected to the rotating shaft through a connection housing.

Preferably, the inner stator yoke core is fixedly connected to the fixed shaft through an end housing.

Preferably, the directions of the salient pole teeth on the outer rotor, the outer stator, the inner rotor and the inner stator all refer to the radial direction.

Preferably, both the inner armature winding and the outer armature winding are multi-phase concentrated armature windings.

Beneficial effects: In the radial magnetic field composite motor of the present invention, the outer stator and outer rotor form an outer motor, and the inner stator and inner rotor form an inner motor; the inner and outer motors are completely independent without electromagnetic coupling, so they can be independently controlled. There are various motor structure options for the inner motor and the outer motor. For example, the outer motor can adopt double salient pole permanent magnet motor and flux reversal motor. In the radial magnetic field composite flux switching motor of the present invention, the cogging of the inner motor and the outer motor's stator and the salient teeth of the rotor, the number of phases and the excitation mode can be flexibly adjusted according to system performance requirements.

Compared with prior art, the present invention has following advantage:

1. There are no permanent magnets on the inner stator and inner rotor of the present invention, so it can avoid irreversible demagnetization of the permanent magnet caused by the difficulty of heat dissipation of the inner motor; although the outer motor has permanent magnets, due to the role of the bearing on the stator, under high-speed working conditions, The speed regulation is completed by the inner motor, and the outer stator of the outer motor can always work near the rated point by rotating in the same direction when the rotor rotates at high speed. While increasing the torque output, it avoids the permanent magnet caused by the weak magnetic field speed regulation of the outer motor Risk of irreversible demagnetization; from the above two points, the present invention improves the working stability of the permanent magnet and improves the reliability of the motor.

2. In the present invention, the inner stator and the inner rotor form a speed-regulating motor, which has a wider speed-regulating range. The outer stator and the outer rotor form a permanent magnet torque-adjusting motor, which has a larger torque output capability. The two motors are used for Adjust the speed and torque to meet the power demand of the load under different working conditions, and meet the requirements of the drive system for low speed, high torque and wide speed range.

3. In the present invention, the inner motor and the outer motor can operate in different working modes such as independent drive or common drive, and when the permanent magnet of the torque-adjusting outer motor fails, the speed-regulating inner motor can be operated independently, so the motor in the present invention Has a certain degree of fault tolerance.

Description of drawings

Figure 1 is a cross-sectional view of a radial magnetic field composite flux switching motor with an inner motor of 3-phase stator with 12 slots/rotor with 8 poles and an outer motor with a 3-phase stator with 12 slots/rotor with 22 poles.

Fig. 2 is a cross-sectional view of the radial field composite flux switching motor of the present invention.

In the figure: 1 outer rotor, 2 outer stator, 3 inner stator, 4 inner rotor, 21 outer armature winding, 22 permanent magnet, 23 bearing, 31 inner armature winding, 5 rotating shaft, 6 fixed shaft, 7 connecting shell, 8 end shell.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings.

This embodiment provides a radial magnetic field compound flux switching motor, which mainly includes a fixed shaft 6, a rotating shaft 5 coaxially rotatably connected with the fixed shaft 6, an inner rotor 4 surrounding the rotating shaft 5, and an inner stator surrounding the inner rotor 4 3. The bearing 23 surrounding the inner stator 3, the outer stator 2 surrounding the bearing 23, and the outer rotor 1 surrounding the outer stator 2. An air gap is provided between the outer stator 2 and the outer rotor 1, and an air gap is provided between the inner stator 3 and the inner rotor 4. The side of the outer rotor 1 facing the outer stator 2 and the side of the inner rotor 4 facing the inner stator 3 are both There are salient pole teeth without windings, the outer stator 2 is provided with salient pole teeth and the outer armature winding 21 wound on the salient pole teeth, and the inner stator 3 is provided with salient pole teeth and the inner electric coil wound on the salient pole teeth. Pivot winding 31. The radially inner edge of the yoke of the inner rotor 4 is fixed on the rotating shaft 5, the radially outer edge of the yoke core of the outer rotor 1 is fixedly connected to the rotating shaft 5 through the connecting shell 7, and the yoke core of the inner stator 3 passes through the end shell 8 is connected and fixed with the fixed shaft 6 on the other side. A bearing 23 is arranged between the inner diameter of the outer stator 2 and the outer diameter of the inner stator 3. The inner and outer sides of the radial direction of the bearing 23 are respectively connected with the outer diameter of the inner stator 3 and the inner diameter of the outer stator 2. The outer stator 2. Permanent magnets 22 that are tangentially and alternately magnetized are arranged in the salient pole teeth. It should be pointed out that, in the present invention, the orientation of the salient poles of the stator and the rotor both refer to the radial direction.

Figure 1 shows a radial magnetic field compound flux switching motor with a 3-phase stator with 12 slots/rotor with 8 poles as the inner motor and a 3-phase stator with 12 slots/rotor with 22 poles as the outer motor. The motor is used as an example below for details The technical solution of this embodiment is demonstrated.

The outer stator 2 has 12 permanent magnets 22 distributed along the circumference, and between two adjacent permanent magnets 22 is an iron core groove unit, whose notch faces the outer rotor 1, and the 12 iron core groove units and 12 permanent magnets alternate along the circumference placed, each permanent magnet 22 and its tangential two adjacent stator teeth form a salient pole tooth of an outer stator 2, and 12 winding coils are wound on the 12 salient pole teeth of the outer stator 2, wherein each interval is 90 The four winding coils of the same degree are connected in series in the same direction to form a concentrated winding of one phase, thereby forming a concentrated armature winding of three phases, that is, the outer armature winding 21. The number of salient pole teeth of the outer rotor 1 is 22, and its salient pole teeth face the outer stator 2 . The outer rotor 1, the outer stator 2, the permanent magnet 22 on them and the outer armature winding 21 form a three-phase 12/22 pole permanent magnet flux switching outer motor. The inner stator 3 is an inner salient pole tooth structure, without permanent magnets on it, and 12 armature winding coils are sheathed on the 12 salient pole teeth, and every 4 are connected in series to form a concentrated winding of one phase, thereby forming a three-phase inner armature winding. That is, the inner armature winding 31, the number of salient pole teeth of the inner rotor 4 is 8, the inner rotor 4, the inner stator 3 and the inner armature winding 31 on it form a three-phase 12/8 pole switched reluctance inner motor.

The above-mentioned inner motor adopts a switched reluctance motor, which has a simple structure and is suitable for high-speed operation. The motor is easy to cool, and because there are no permanent magnets on the inner stator 3 and inner rotor 4, a higher temperature rise is allowed. The above-mentioned outer motor adopts a permanent magnet flux switching motor structure, and the outer rotor has a simple structure, and has high torque density and high efficiency. Since the outer rotor 1 and the inner rotor 4 are fixedly connected to the rotating shaft 5, the inner motor and the outer motor have the same rotor speed, the inner stator 3 is fixed on the fixed shaft 6, and has no speed, and the outer stator 2 can be rotated according to the bearing 23 The working condition rotates at a certain speed.

In this embodiment, the inner motor mainly completes the speed regulation of the motor according to the operation requirements, so that the rotating shaft 5 rotates at the target speed, and at the same time outputs a certain torque; the outer motor can make the outer stator 2 and the outer rotor 1 rotate in the same direction at a differential speed, Make the outer motor work near the rated point with higher efficiency, and make up for the lack of output torque of the inner motor. Therefore, the inner and outer motors are respectively responsible for speed regulation and torque regulation. The inner motor is small in size, suitable for high-speed operation, and has no permanent magnets, so no permanent magnets are required to participate in the field-weakening speed regulation during the speed regulation process; at the same time, the outer motor has a large torque density and has Larger torque output capacity, and due to the function of the bearing 23, the outer motor can always work near the rated point under different working conditions, so whether it is running at low speed or high speed, the lack of output torque of the inner motor can be solved by the outer motor Provided, so as to realize the motor's demand for low-speed high-torque and wide speed range operation.

There is no electromagnetic coupling between the inner and outer motor systems of this composite motor, and it can be independently controlled according to two ordinary motors. The controllable parameters are much more than ordinary flux switching motors, and it is very flexible. The inner and outer motors can operate in different working modes such as single-machine drive, double-machine joint drive, and double-machine power generation according to different working conditions. When both the inner and outer motors are used for power generation, they can output two sets of different power, frequency, and amplitude. and voltage levels of electric energy; the internal and external motor systems can also be used for power generation operation, and the other for electric operation to meet different application occasions and performance requirements.

The motor proposed by the invention integrates the permanent magnet flux switching outer motor and the switched reluctance inner motor in a radial magnetic field motor space, and provides two power flow paths. Both the inner motor and the outer motor can adopt other motor structures, which greatly improves the flexibility of the system and expands the scope of application.

The above-mentioned embodiments are only for illustrating the technical concept and characteristics of the present invention, and its purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and not to limit the scope of protection of the present invention. All equivalent changes or modifications made according to the spirit of the present invention shall fall within the protection scope of the present invention.

Claims (10)

1. A radial magnetic field composite type flux switching motor is characterized by comprising a fixed shaft (6), a rotating shaft (5) coaxially and rotatably connected with the fixed shaft (6), an inner rotor (4) surrounding the rotating shaft (5), an inner stator (3) surrounding the inner rotor (4), a bearing (23) surrounding the inner stator (3), an outer stator (2) surrounding the bearing (23), and an outer rotor (1) surrounding the outer stator (2); air gaps are arranged between the outer stator (2) and the outer rotor (1) and between the inner stator (3) and the inner rotor (4); the inner rotor (4) and the outer rotor (1) are fixedly connected with the rotating shaft (5), the inner stator (3) is fixedly connected with the fixed shaft (6), and the radial inner side and the radial outer side of the bearing (23) are respectively connected with the outer diameter of the inner stator (3) and the inner diameter of the outer stator (2).

2. The radial magnetic field composite flux switching motor according to claim 1, wherein salient pole teeth are provided on the opposite sides of the outer rotor (1) and the outer stator (2) and the opposite sides of the inner rotor (4) and the inner stator (3), and no winding is provided on the salient pole teeth of the outer rotor (1) and the inner rotor (4), an outer armature winding (21) and a permanent magnet (22) are provided on the salient pole teeth of the outer stator (2), and an inner armature winding (31) is provided on the salient pole teeth of the inner stator (3).

3. A radial-field hybrid flux-switching electric machine according to claim 1, characterized in that the number of salient pole teeth of the outer stator (2) isP _soThe outer armature winding (21) is formed by symmetrically distributedP _soOne cover is arranged outsideThe coil on the salient pole teeth of the stator (2) is formed, and the outer armature winding (21) ismA phase concentrated winding, satisfyP _so=2k ₁ mWherein isk ₁A positive integer;

the number of salient pole teeth of the outer rotor (1) isP _roSatisfy the following requirementsP _ro=P _so±2N₁In which N is₁Is a positive integer.

4. A radial magnetic field composite flux switching electric machine according to claim 3, characterized in that the number of salient pole teeth of the inner stator (3) isP _siThe inner armature winding (31) is formed by symmetrically distributedP _siA coil sleeved on the salient pole teeth of the inner stator (3), and the inner armature winding (31) isnA phase concentrated winding, satisfyP _si=2k ₂ nWherein isk ₂A positive integer;

the number of the salient pole teeth of the inner rotor (4) isP _riSatisfy the following requirementsP _ri=P _si±2N₂In which N is₂Is a positive integer.

5. Radial field compound flux switching electrical machine according to any of claims 1 to 4, characterized in that the permanent magnets (22) are tangentially alternately magnetized permanent magnets.

6. A radial magnetic field composite flux switching electric machine according to any of claims 1 to 4, characterized in that the radially inner edge of the yoke part of the inner rotor (4) is fixed to the rotating shaft (5).

7. The radial magnetic field composite flux switching motor according to any one of claims 1 to 4, wherein a radially outer edge of a yoke core of the outer rotor (1) is fixedly connected to the rotating shaft (5) through a connection housing (7).

8. A radial magnetic field composite flux switching electric machine according to any of claims 1 to 4, characterized in that the inner stator (3) yoke core is fixedly connected with the fixed shaft (6) by means of an end housing (8).

9. A radial-magnetic-field-combined-type flux-switching electric machine according to any of claims 1 to 4, characterized in that the salient-pole teeth on the outer rotor (1), the outer stator (2), the inner rotor (4) and the inner stator (3) are oriented in the radial direction.

10. A radial-field composite flux-switching electric machine according to any of claims 1 to 4, characterized in that the inner armature winding (31) and the outer armature winding (21) are both multiphase concentrated armature windings.