CN102035333A - Permanent magnet switched reluctance motor employing distributed winding - Google Patents

Abstract

The invention discloses a permanent magnet switched reluctance motor adopting distributed windings, which comprises a stator and a rotor sleeved inside the stator. The stator and the rotor are both annular salient pole structures, and the inner ring surface of the stator is provided with evenly distributed stators. There are evenly distributed rotor teeth on the surface of the outer ring of the rotor. There is a gap between the stator core and the rotor core that are nested in each other. The permanent magnet is embedded in the yoke of the stator core; the stator adopts a three-phase armature winding with a distributed structure. , there is only one winding coil between adjacent stator slot bodies, every coil across two stator slots is connected to form a phase winding, the mutual inductance between the three-phase windings is coupled with each other, and there are always two phase windings excited and energized at any time during operation; The interaction output torque of the armature winding and the permanent magnet is greater than the output torque of the armature winding alone excitation. The invention solves the problems of low utilization rate of windings of the existing switched reluctance motor and low power density of the motor. The motor of the present invention can be used as both a motor and a generator.

Description

Permanent magnet switched reluctance motor with distributed winding

technical field

The invention belongs to the field of motors and relates to a permanent magnet switched reluctance motor with distributed windings.

Background technique

The stator and rotor of the traditional switched reluctance motor adopt a salient pole structure, and the stator winding is generally a concentrated winding. By sequentially energizing the stator excitation winding, the stator pole and the rotor pole interact to generate torque. Since there are neither windings nor permanent magnets on the rotor, the structure of the motor is simple and the operation is reliable. However, this traditional switched reluctance motor has only one phase excitation at any time when it is working. In a switching cycle of the stator winding, at most only half of the cycle is used. In order to obtain a larger output torque and power, the size of the motor requires Relatively large, thereby reducing the performance volume ratio of the motor.

In order to overcome the shortcomings of the traditional switched reluctance motor, people put forward the idea of embedding permanent magnets in the motor to improve the performance of the motor. There is a switched reluctance motor, which embeds permanent magnet materials in the stator core of the motor. The change of this structure is greatly The output torque ripple of the motor is effectively suppressed, and the performance volume ratio and performance weight ratio of the motor are also improved. However, since the windings of this permanent magnet switched reluctance motor are concentrated windings, there are two winding coils between the adjacent stator slots, and only one phase is still energized at any time during operation. , at most only half a cycle is utilized, the utilization rate of the winding is relatively low, the mutual inductance between the windings is independent, and the power density of the motor needs to be further improved.

Contents of the invention

In order to solve the problems of low utilization rate of existing switched reluctance motor windings and low motor power density, the present invention provides a three-phase permanent magnet switch that can make full use of materials, adopt a distributed winding structure, and have relatively high motor power density reluctance motor.

In order to achieve the above object, the technical scheme adopted in the present invention is as follows:

A permanent magnet switched reluctance motor with distributed windings, including a stator and a rotor sleeved inside the stator. Both the stator and the rotor have a ring-shaped salient pole structure. There are evenly distributed rotor teeth, and there is a gap between the mutually socketed stator core and the rotor core, and the permanent magnet is embedded in the yoke of the stator core. It is characterized in that: the stator adopts a three-phase armature winding with a distributed structure, and there is only one winding coil between adjacent stator slot bodies, and every coil that crosses two stator slots is connected to form a phase winding, and there is always a winding at any time during operation. When the two-phase windings are energized, the one-phase windings are fully utilized within one switching cycle, and the mutual inductance between the three-phase windings is coupled to each other, which improves the utilization rate of the windings. The magnetic field generated by the armature winding and the permanent magnet interacts to generate torque, and its output torque is greater than the output torque of the armature winding alone, which improves the power density of the motor.

The present invention is further characterized in that:

The ratio of the number of stator teeth to rotor teeth is 6:4, and the number of poles is 6/4 or 12/8.

The stator is composed of a stator core made of laminated silicon steel sheets and a permanent magnet, and the rotor is made of laminated silicon steel sheets.

The permanent magnets are magnetized in a tangential direction, and the polarities of adjacent permanent magnets are opposite.

The present invention is characterized in that:

(1) The stator armature winding adopts a distributed structure. There is only one winding coil between the adjacent stator slot bodies, and the coils that cross two stator slots are connected to form a one-phase winding. There are always two phases at any time when the motor is working. When the armature winding is energized, all one-phase windings are fully utilized in one switching cycle, which improves the utilization rate of the winding and improves the shortcomings of the previous centralized windings that only half of a cycle is utilized in a switching cycle.

(2) The number of phases of the stator armature winding is three phases. When the motor is working, the two phases are simultaneously turned on at any time. When the motor is turned on, the mutual inductance between the windings of each phase is coupled with each other, and the torque is generated by using the change of the mutual inductance between the windings, which improves the circuit and The utilization rate of the magnetic circuit improves the torque output capability and power density.

(3) The ratio of stator teeth to rotor teeth is 6:4, and the number of poles can be 6/4 or 12/8. The more poles of the stator and rotor, the smaller the pulsation of the output torque of the motor, the smaller the vibration of the motor, and the more stable the operation.

(4) When the motor is working, the magnetic field generated by the armature winding interacts with the magnetic field generated by the permanent magnet of the stator yoke, and the two excitation sources are coupled with each other, and the total magnetic flux is more than the magnetic flux of the single excitation winding, making the motor The output torque increases, not only increases the output force, but also increases the power density.

Based on the above characteristics, the present invention solves the problems of low utilization rate of the existing switched reluctance motor windings and low power density of the motor; and the motor can be used as both a motor and a generator. The invention can meet the application in the fields of aerospace (such as aerodynamics/generators of aircraft), traffic equipment (such as electric vehicles) and the like in the future, so as to promote the development of industries such as national defense and modern transportation.

Description of drawings

Fig. 1 is a structural schematic diagram of a permanent magnet switched reluctance motor of the present invention.

Fig. 2 is a schematic diagram of the magnetic flux closed path of the permanent magnet when no power is applied.

Figure 3 is the closed path of magnetic flux generated by the windings and permanent magnets when the A and B phase windings are energized.

Figure 4 is the closed path of magnetic flux generated by the windings and permanent magnets when the B and C phase windings are energized.

In the figure: 1. stator; 2. rotor; 3. armature winding; 4. stator core; 5. permanent magnet; 6. rotor teeth; 7. stator teeth.

Detailed ways

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

Fig. 1 is a schematic structural diagram of a permanent magnet switched reluctance motor using distributed windings in the present invention. The motor includes a stator 1 and a rotor 2 socketed inside the stator. Both the stator 1 and the rotor 2 are ring-shaped salient pole structures. The stator 1 The surface of the inner ring is provided with evenly distributed stator teeth 7, and the surface of the outer ring of the rotor 2 is provided with uniformly distributed rotor teeth 6. There is a gap between the mutually nested stator core 4 and the rotor core 2, and the permanent magnet 5 is embedded in the stator. Iron core 4 yoke, in which: the stator 1 is wound with a three-phase armature winding 3 composed of a distributed structure, and there is only one winding coil between the slots of adjacent stator teeth 7, and the coils that span two stator slots are connected to form One-phase winding, for example, A+ and A- are connected as one phase, B+ and B- are connected as one phase, and C+ and C- are connected as one phase. There is no winding on rotor 2.

The further structure of the present invention is that, for the three-phase armature winding in a distributed structure, the ratio of the number of stator teeth 7 to rotor teeth 6 is 6:4, and the number of poles can be 6/4 or 12/8.

The stator of the present invention is composed of a stator core 4 made of laminated silicon steel sheets and permanent magnets, and the rotor 2 is made of laminated silicon steel sheets. The permanent magnets 5 adopt a tangential magnetization method, and the adjacent permanent magnets 5 have opposite polarities.

The armature winding 3 of the motor of the present invention is a distributed winding structure. There is only one winding coil in a stator slot, and the coils that cross two stator slots are connected to form a phase winding. There are always two phase armature windings at any time when the motor is working. When energized and excited, the mutual inductance of each phase winding is coupled to each other, and one phase winding is fully utilized in one switching cycle. The torque is generated by using the change of the mutual inductance between the windings and the interaction of the magnetic field of the permanent magnet, which improves the utilization rate of the circuit and the magnetic circuit, and improves the torque output capability and power density.

The working principle of permanent magnet switched reluctance motor with distributed winding is as follows:

The permanent magnet switched reluctance motor winding proposed by the present invention is a distributed winding, as shown in Figure 1, there are always two phase windings energized and excited at any time during operation, and the mutual inductance between the windings of each phase is coupled to each other. When the stator excitation winding is not energized, the stator and rotor poles of the motor are in the aligned position, and the magnetic flux closed path of the tangentially magnetized permanent magnet 5 at the yoke of the stator core 4 is: the N pole of the permanent magnet 5 → the yoke of the stator core 4 → the pole portion of the stator core 4 → the pole portion of the rotor core 2 → the yoke portion of the rotor core 2 → the pole portion of the rotor core 2 → the pole portion of the stator core 4 → the yoke portion of the stator core 4 → the S pole of the permanent magnet 5, as shown in picture 2.

When the A and B phases of the stator excitation winding are energized, the magnetic flux closed path generated by the A and B phase windings and the tangentially magnetized permanent magnet 5 of the yoke of the stator core 1 is divided into two parts, the first part: the permanent magnet 5 N pole → pole part of stator core 1 → rotor core 2 → pole part of stator core 1 → yoke part of stator core 1 → S pole of permanent magnet 5, second part: yoke part of stator core 4 → part of stator core 4 Pole part → rotor core 2 → pole part of stator core 4 → yoke part of stator core 4, at this time, the mutual inductance of A and B phase windings is coupled with each other. As shown in Figure 3.

When the B and C phases of the stator excitation winding are energized, the magnetic flux closed path generated by the B and C phase windings and the tangentially magnetized permanent magnet 5 of the stator core 4 yoke is also divided into two parts, and the magnetic flux closed path is the same as A and B phases are similar when they are energized, and at this time, the mutual inductance of B and C phase windings are coupled with each other. As shown in Figure 4.

The working principle of permanent magnet switched reluctance motor with distributed winding is as follows. When the field winding is not energized, the magnetic field lines generated by the permanent magnet 5 are closed along the poles and yoke paths of the stator core 4 and the rotor core 2; A parallel magnetic circuit is formed, the direction of the magnetic force lines is consistent, and the two magnetic fields are superimposed on the stator core, air gap and rotor core, and the magnetic flux becomes larger. Control the motor torque by controlling the path and size of the magnetic flux (line of force) through the switching action of the electric excitation magnetic potential (that is, the opening and closing of the winding current).

The switched reluctance motor of the invention adopts windings with a distributed structure, and the mutual inductance among the three-phase windings is coupled with each other, so that the two-phase windings are always energized at any time during operation, which improves the utilization rate of the windings. At the same time, the permanent magnet 5 is embedded in the yoke of the stator core 4, and the electric excitation circuit of the excitation winding and the tangential excitation circuit of the permanent magnet 5 are organically combined. The electric excitation magnetic potential has both the excitation function and the control of the excitation field of the permanent magnet 5. function, so that the two excitation sources of the motor are also coupled with each other, and the total magnetic flux is more than the magnetic flux of the single excitation winding, so that the output torque of the motor increases, that is to say, under the same condition of required output torque , the excitation current required by the motor of the present invention is smaller than that of a common switched reluctance motor, so the motor of the present invention has high efficiency.

The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments. It cannot be considered that the embodiments of the present invention are limited thereto. Simple modifications and equivalent structural changes or modifications all belong to the scope of protection determined by the claims submitted in the present invention.

Claims (4)

1. A permanent magnet switched reluctance motor with distributed windings, including a stator (1) and a rotor (2) socketed inside the stator. Both the stator (1) and the rotor (2) are ring-shaped salient pole structures, and the stator ( 1) The surface of the inner ring is provided with evenly distributed stator teeth (7), and the surface of the outer ring of the rotor (2) is provided with uniformly distributed rotor teeth (6). There is a gap between them, and the permanent magnet (5) is embedded in the yoke of the stator core (4). There is only one winding coil between the slots, and every coil across two stator slots is connected to form a phase winding, the mutual inductance of the three-phase windings is coupled with each other, and the armature winding (3) and the permanent magnet (5) interact to output torque It is greater than the armature winding alone excitation output torque. 2. The permanent magnet switched reluctance motor with distributed windings according to claim 1, characterized in that: the stator (1) is composed of a stator core (4) made of silicon steel sheets and a permanent magnet (5) , the rotor (2) is formed by stacking silicon steel sheets. 3. The permanent magnet switched reluctance motor with distributed windings according to claim 1, characterized in that: the ratio of the number of the stator teeth (6) to the rotor teeth (7) is 6:4, and the number of poles Available in 6/4 or 12/8 format. 4. The permanent magnet switched reluctance motor with distributed windings according to claim 1, characterized in that: the permanent magnets (5) are magnetized in a tangential direction, and the polarities of adjacent permanent magnets (5) are opposite.

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