CN109936230A - A series magnetic circuit type double-layer hybrid permanent magnet memory motor - Google Patents

Abstract

The invention discloses a series magnetic circuit type double-layer hybrid permanent magnet memory motor, comprising a stator, an armature winding, a hybrid permanent magnet rotor and a rotating shaft. The rotor core of the hybrid permanent magnet rotor is arranged around the outside of the rotating shaft, and the The stator is arranged around the outside of the hybrid permanent magnet rotor, the armature winding is arranged on the stator, and each pole of the rotor core is provided with a radially magnetized first permanent magnet, two tangentially magnetized permanent magnets The second permanent magnet and an in-line magnetic barrier, the first permanent magnet is placed in an in-line shape by the air gap side, and the ends of the two second permanent magnets away from the rotating shaft are respectively placed close to one end of the first permanent magnet, The in-line magnetic barrier is arranged between the ends of the two second permanent magnets close to the rotating shaft, and the coercive force of the second permanent magnets is greater than the coercive force of the first permanent magnets. The invention can effectively solve the problems of narrow magnetic regulation range and high required magnetic regulation current of the traditional series magnetic circuit structure, and at the same time reduce the risk of load demagnetization when the motor is running.

Description

A series magnetic circuit type double-layer hybrid permanent magnet memory motor

technical field

The invention relates to a permanent magnet memory motor, in particular to a series magnetic circuit type double-layer hybrid permanent magnet memory motor.

Background technique

Permanent Magnet Synchronous Machine (PMSM) has the advantages of high power density, high efficiency, reliable operation and strong overload capacity due to the use of traditional rare earth permanent magnet materials (such as NdFeB) with higher magnetic energy products. But at this time, the air-gap magnetic field in the motor remains basically constant, and the speed regulation range is very limited during electric operation, and the application in wide speed regulation direct drive occasions such as electric vehicles and aerospace is limited, so the permanent magnet motor is realized. The tunable flux permanent magnet motor aiming at the effective adjustment of the air gap magnetic field has always been a hot and difficult point in the field of motor research. Permanent magnet memory motor (hereinafter referred to as "memory motor") is a new type of permanent magnet motor with controllable magnetic flux. The magnetization of the permanent magnet is changed to adjust the air gap magnetic field, and the permanent magnet has the feature that the magnetic density level can be memorized.

The memory motor with the traditional topology structure is developed from the write-pole motor, and the rotor is composed of a sandwich structure of AlNiCo permanent magnets, non-magnetic interlayers and rotor cores. This special structure can realize on-line repeated irreversible charging and demagnetization of the permanent magnet at any time, and at the same time reduce the influence of the quadrature-axis armature reaction on the air-gap magnetic field. Most of the existing researches focus on the AC magnetization type hybrid permanent magnet memory motor. There are two kinds of permanent magnets of different materials inside the rotor for the common excitation. Among them, the NdFeB permanent magnet provides the main magnetic field of the air gap, and the AlNiCo permanent magnet generates the main magnetic field. The role of magnetic field regulation. The stator winding has both functions of power control and magnetic regulation.

Prior art CN108599418A proposes a rotor core and a motor of a magnetic circuit series-type hybrid permanent magnet controllable flux motor. The motor adopts a series magnetic circuit structure to enhance the magnetization effect of the low-coercivity permanent magnet and reduce the size of the motor. The high magnetizing current ensures the positive magnetization of the low-coercivity permanent magnet and improves the working point of the permanent magnet. However, in this structure, the demagnetizing magnetomotive force needs to directly pass through two types of permanent magnets, which increases the required demagnetizing current and the capacity of the inverter. The positive effect of magnetism, the magnetic adjustment range of the motor is narrow.

SUMMARY OF THE INVENTION

Purpose of the invention: The present invention aims at the problems existing in the prior art, and provides a series magnetic circuit type double-layer hybrid permanent magnet memory motor, which solves the problems of narrow magnetic regulation range and required magnetic regulation current ( magnetization and demagnetization) and the capacity of the inverter is too large.

Technical solution: The series magnetic circuit type double-layer hybrid permanent magnet memory motor according to the present invention includes a stator, an armature winding, a hybrid permanent magnet rotor and a rotating shaft, and the rotor core of the hybrid permanent magnet rotor is arranged around the outside of the rotating shaft, The stator is arranged around the outside of the hybrid permanent magnet rotor, and the armature winding is arranged on the stator. It is characterized in that: each pole of the rotor core is provided with a radially magnetized first permanent magnet, Two tangentially magnetized second permanent magnets and an in-line magnetic barrier, the first permanent magnets are placed in an in-line shape on the side of the air gap, and the ends of the two second permanent magnets away from the rotating shaft are respectively close to the first One end of the permanent magnet is placed, the in-line magnetic barrier is arranged between the ends of the two second permanent magnets close to the rotating shaft, and the coercive force of the second permanent magnet is greater than that of the first permanent magnet.

Further, the second permanent magnet is arranged symmetrically with respect to the central axis of the first permanent magnet, and the first permanent magnet coincides with the central axis of the in-line magnetic barrier.

Further, a magnetic bridge is provided between the in-line magnetic barrier and the end of the second permanent magnet close to the rotating shaft.

Further, the magnetization directions of the first permanent magnets of the adjacent poles are opposite, the magnetization directions of the two second permanent magnets of the same pole are opposite, and the magnetization directions of the adjacent two second permanent magnets of the adjacent poles are the same.

Further, the number of the first permanent magnets and the in-line magnetic barriers is the same and an even number, and the number of the second permanent magnets is twice the number of the first permanent magnets.

Further, the first permanent magnet is an AlNiCo permanent magnet, and the second permanent magnet is a NdFeB permanent magnet.

Beneficial effect: Compared with the prior art, the present invention has the following significant advantages:

1. The present invention separates the first permanent magnet and the second permanent magnet in space by adopting the structural design of the double-layer permanent magnet, weakens the positive effect of the second permanent magnet on the first permanent magnet, and improves the motor performance. The magnetic adjustment range;

2. The present invention ensures that most of the permanent magnet magnetic field is short-circuited inside the rotor when the motor is in a weak magnetic state by setting the in-line magnetic barrier, which further improves the on-line magnetic adjustment range of the motor;

3. In the present invention, the first permanent magnet is placed on the side of the air gap in the direction of the straight axis, and a magnetic bridge structure is arranged on the straight axis path, so as to provide a direct axis path of the magnetomotive force for magnetic regulation, so as to reduce the magnetic regulation current;

4. The present invention reduces the risk of accidental demagnetization caused by the influence of the magnetizing current on the second permanent magnet by arranging the second permanent magnet on both sides below the first permanent magnet of each pole.

Description of drawings

1 is a cross-sectional structural diagram of a motor of the present invention;

Fig. 2 is the distribution diagram of magnetic field lines during the forward magnetization of the first permanent magnet of the motor of the present invention;

FIG. 3 is a distribution diagram of magnetic field lines when the first permanent magnet of the motor of the present invention is reversely magnetized.

Detailed ways

Referring to FIG. 1 , the series magnetic circuit type double-layer hybrid permanent magnet memory motor involved in this embodiment includes a stator 1 , an armature winding 2 , a hybrid permanent magnet rotor 3 and a non-magnetically conductive shaft 4 . The non-magnetically conductive rotating shaft 4 , the hybrid permanent magnet rotor 3 and the stator 1 are arranged in sequence from the inside to the outside. The stator 1 includes stator core teeth 1.1 and a stator yoke 1.2, the stator core teeth 1.1 are arranged between the stator yoke 1.2 and the hybrid permanent magnet rotor 3, and a cavity 1.3 is formed between the adjacent stator core teeth 1.1, which is used for placing winding on the stator core. Three-phase armature winding 2 on tooth 1.1. The rotor core 3.1 of the hybrid permanent magnet rotor 3 is arranged around the outside of the non-magnetically conductive rotating shaft 4, and each pole of the rotor core 3.1 is provided with a radially magnetized first permanent magnet 3.3 and two tangentially magnetized second permanent magnets 3.2 And one in-line magnetic barrier 3.4, the first permanent magnet 3.3 is placed in a in-line shape by the air gap side, and the ends of the two second permanent magnets 3.2 away from the shaft 4 are respectively placed close to one end of the first permanent magnet 3.3, the in-line magnetic barrier 3.4 is arranged between the ends of the two second permanent magnets 3.2 close to the rotating shaft 1 . The first permanent magnet 3.3 and the second permanent magnet 3.2 form a double-layer permanent magnet structure, and the first permanent magnet 3.3 and the second permanent magnet 3.2 are connected in series on the magnetic circuit. The second permanent magnet 3.2 under the same pole is arranged symmetrically with respect to the central axis of the first permanent magnet 3.3, and the first permanent magnet 3.3 coincides with the central axis of the in-line magnetic barrier 3.4. A magnetic bridge 3.5 is provided between the in-line magnetic barrier 3.4 and the end of the second permanent magnet 3.3 on the side of the rotating shaft. The setting of the magnetic bridge 3.5 is to provide a direct-axis path of the magnetomotive force for magnetic regulation, thereby reducing the required magnetic regulation current. The magnetization directions of the first permanent magnets 3.3 of adjacent poles are opposite, the magnetization directions of the two second permanent magnets 3.2 of the same pole are opposite, and the magnetization directions of the two adjacent second permanent magnets 3.2 between adjacent poles are the same . In this embodiment, the number of the first permanent magnets 3.3 and the in-line magnetic barriers 3.4 is four, and the number of the second permanent magnets 3.2 is eight. The first permanent magnet 3.3 adopts AlNiCo permanent magnet, and the second permanent magnet 3.2 adopts NdFeB permanent magnet.

Please refer to FIG. 2 and FIG. 3 , the operating principle of the series magnetic circuit type double-layer hybrid permanent magnet memory motor of the present embodiment is as follows: the permanent magnet magnetic flux first flows from the second permanent magnet 3.2 arranged on the rotor core 3.1 along the circumferential radial direction. Starting from the north pole, part of it goes directly through the rotor core 3.1 and returns directly to the south pole of the second permanent magnet 3.2, and a part reaches the south pole of the first permanent magnet 3.3. If the first permanent magnet 3.3 is magnetized along the direction of the magnetic flux of the second permanent magnet 3.2 in the radial direction of the circumference, the first permanent magnet 3.3 is in the magnetization state, and the two permanent magnetic fluxes flow in the same direction after being superimposed, and pass through the gas The gap reaches the stator core tooth 1.1, then passes through the stator yoke 1.2, and returns to the south pole of the second permanent magnet 3.2 in the same way; if the first permanent magnet 3.3 is opposite to the second permanent magnet 3.2 along the circumferential radial direction Magnetization, at this time, the first permanent magnet 3.3 is in a weak magnetic state, most of the permanent magnetic flux is short-circuited, and a small part returns to the south pole of the second permanent magnet 3.2 according to the above path. The distribution of the magnetic field lines of the first permanent magnet 3.3 in the two magnetization states is shown in FIG. 2 and FIG. 3 . At the same time, the motor armature winding 2 is fed with a three-phase alternating current that is consistent with the rotating speed of the hybrid permanent magnet rotor 3, and the rotating magnetic field formed by the stator and rotor interacts, thereby realizing electromechanical energy conversion. The added in-line magnetic barrier 3.4 and magnetic bridge 3.5 can effectively reduce the required magnetizing current, and the double-layer permanent magnet structure can widen the range of motor magnetizing.

What is disclosed above is only a preferred embodiment of the present invention, which cannot limit the scope of the rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims (6)

1. A series magnetic circuit type double-layer hybrid permanent magnet memory motor, comprising a stator, an armature winding, a hybrid permanent magnet rotor and a rotating shaft, the rotor core of the hybrid permanent magnet rotor is arranged around the outside of the rotating shaft, and the stator surrounds The hybrid permanent magnet rotor is arranged outside, and the armature winding is arranged on the stator. It is characterized in that: each pole of the rotor core is provided with a radially magnetized first permanent magnet, two tangential magnets A magnetized second permanent magnet and an in-line magnetic barrier, the first permanent magnet is placed in an in-line shape on the side of the air gap, and the ends of the two second permanent magnets away from the rotating shaft are respectively close to one end of the first permanent magnet Placed, the in-line magnetic barrier is arranged between the ends of the two second permanent magnets close to the rotating shaft, and the coercive force of the second permanent magnets is greater than the coercive force of the first permanent magnets. 2 . The series magnetic circuit type double-layer hybrid permanent magnet memory motor according to claim 1 , wherein the second permanent magnet is symmetrically arranged with respect to the central axis of the first permanent magnet, and the first permanent magnet is symmetrical. 3 . Coinciding with the central axis of the in-line magnetic barrier. 3 . The series magnetic circuit type double-layer hybrid permanent magnet memory motor according to claim 1 , wherein a magnetic bridge is provided between the in-line magnetic barrier and the end of the second permanent magnet close to the rotating shaft. 4 . 4 . The series magnetic circuit type double-layer hybrid permanent magnet memory motor according to claim 1 , wherein the magnetization directions of the first permanent magnets of adjacent poles are opposite, and the magnetization directions of the two second permanent magnets of the same pole are opposite. 5 . The directions are opposite, and the magnetization directions of two adjacent second permanent magnets of adjacent poles are the same. 5 . The series magnetic circuit type double-layer hybrid permanent magnet memory motor according to claim 1 , wherein the number of the first permanent magnets and the in-line magnetic barriers is the same and an even number, and the number of the second permanent magnets is the same and an even number. 6 . twice the number of the first permanent magnets. 6 . The series magnetic circuit type double-layer hybrid permanent magnet memory motor according to claim 1 , wherein the first permanent magnet is an AlNiCo permanent magnet, and the second permanent magnet is a NdFeB permanent magnet. 7 . .