TWI619331B - Flux switching permanent magnet motor - Google Patents

Abstract

The invention discloses a magnetic flux switching type permanent magnet motor, which includes a motor stator and a motor rotor. The motor stator has twelve stator tooth poles, and permanent magnets are inserted in the stator tooth poles. The magnetism of one surface of the stator tooth poles is the same as that of one surface of an adjacent stator tooth poles. The motor rotor has ten rotor poles. Among them, the motor stator and the motor rotor meet specific conditions.

Description

Flux switching permanent magnet motor

The present invention relates to a motor, and more particularly to a magnetic flux switching type permanent magnet motor.

Among the current high-efficiency motors, commonly known as synchronous reluctance motors, ABB has already shipped and marketed various models of products. This kind of motor does not need magnets at all but has a very high efficiency, which can reach the industrial standard of IE4. However, the minimum motor capacity to reach 90% efficiency also requires more than 7.5KW, which is energy saving for small and medium capacity motor products with power within 1KW. It doesn't seem to help much.

ABB continues to develop a more efficient "permanent magnet assisted synchronous reluctance motor". This motor does not require rare permanent magnets, but has extremely high efficiency, which can reach the level of IE5. However, in many fields of automation or electric vehicles that need to improve endurance, they often face the problem of insufficient low-speed torque and still need to be strengthened. Among the existing high-efficiency motors, it seems difficult to find such motors.

On the other hand, another quite different motor design concept has emerged. It is derived from the fixed rotor structure design of the "switched reluctance motor". In recent years, it has combined the superior characteristics of the "double salient pole permanent magnet motor".

As mentioned above, this motor retains the superior performance of the "switched reluctance motor" and "double salient pole permanent magnet motor". The rotor can be free of any permanent magnets, and its shape is similar to that of the "switched reluctance motor". Rotor, so it is not necessary in a very harsh working environment, such as working at 600 degrees Celsius Worry about rotor failure or permanent magnet demagnetization. And because of its advantages of "double salient pole permanent magnet motor", it has the excellent characteristics of "traditional permanent magnet synchronous motor". In addition, the permanent magnet built in the fixed part is easy to dissipate heat. The problem of demagnetization of the permanent magnet in the fixed part is also Can be ruled out indirectly.

However, despite its above-mentioned advantages, the characteristics and design of the motor still remain in academic research, and there is still a gap between the applicable goals of the industry and cannot be implemented accordingly.

In view of the above-mentioned conventional problems, an object of the present invention is to provide a magnetic flux switching type permanent magnet motor to solve the problems faced in the conventional technology.

Based on the above objective, the present invention provides a magnetic flux switching type permanent magnet motor including a motor stator and a motor rotor. The motor stator has twelve stator tooth poles. Permanent magnets are inserted in each stator tooth pole. The permanent magnets corresponding to one surface of each stator tooth pole and the corresponding one of adjacent stator tooth poles have the same magnetic properties. The two adjacent stator tooth poles have the same magnetic properties. Cogged. The motor rotor has ten rotor poles. Among them, the motor stator and the motor rotor meet the following conditional expressions: b _i = 0.1545T _s ; S = R _si / R _so = 0.618 ; b _p = 0.4045T _s ; and b _h = 0.5T _s ; where b _m is the thickness of the permanent magnet and b _t is the thickness without the permanent magnet 1/2 width of the stator poles, b _s is the width of the cogging, b _i is the thickness of the stator yoke of the stator teeth, b _p is the width of the rotor poles, b _h is the height of the rotor poles, and R _si is the motor stator The inner diameter, R _so is the outer diameter of the motor stator, S is the ratio of the inner and outer diameter of the motor stator, and T _s is the cogging pitch of the stator tooth poles.

Preferably, each stator tooth pole can be connected by a stator yoke, and each stator yoke corresponds to a cogging, respectively.

Preferably, the part of the permanent magnet corresponding to the stator yoke may be replaced with a non-magnetic material.

Preferably, there may be an air gap between the motor stator and the motor rotor.

Preferably, the width of the air gap can be the inner diameter of the motor stator minus the outer diameter of the motor rotor.

As mentioned above, the magnetic flux switching type permanent magnet motor of the present invention has a structure design of 12 stator tooth poles and 10 rotor poles, and a permanent magnet is inserted into the stator tooth poles, so that the magnetic flux switching type permanent magnet of the present invention The magnetic motor can simplify the complicated design of the conventional motor, and can effectively reduce the sudden torque and torque ripple of the conventional motor.

110‧‧‧Motor stator

111‧‧‧Stator tooth pole

112‧‧‧Groove

113‧‧‧Stator yoke

120‧‧‧motor rotor

121、121’‧‧‧rotor pole

130‧‧‧ permanent magnet

131‧‧‧part of permanent magnet corresponding to stator yoke

FIG. 1 is a schematic structural diagram of a magnetic flux switching type permanent magnet motor according to the present invention.

FIG. 2 is a schematic diagram of a single module of a magnetic flux switching type permanent magnet motor according to the present invention.

FIG. 3 is a magnetic field line distribution diagram of the magnetic flux switching type permanent magnet motor of the present invention.

FIG. 4 is a waveform diagram of the opposite electromotive force of the magnetic flux switching type permanent magnet motor of the present invention.

FIG. 5 is an electromagnetic torque waveform diagram of the magnetic flux switching type permanent magnet motor of the present invention.

In order to better understand the features, contents and advantages of the present invention and the effects that can be achieved, the present invention is described in detail with the drawings in the form of examples, and the main purpose of the drawings is only The use of illustrations and auxiliary descriptions may not be the actual proportions and precise configurations after the implementation of the present invention, so the accompanying drawings should not be interpreted and limited to the scope of rights of the present invention in actual implementation.

The advantages, features, and technical methods of the present invention will be described in more detail with reference to the exemplary embodiments and the accompanying drawings for easier understanding, and the present invention may be implemented in different forms. Therefore, it should not be understood that the present invention is limited to the embodiments described herein. On the contrary, for those having ordinary knowledge in the technical field, the embodiments provided will make this disclosure more thoroughly, comprehensively and completely convey the scope of the present invention. And the present invention will only be defined by the scope of the attached patent application.

Please refer to Figs. 1 and 2; Fig. 1 is a schematic structural diagram of a magnetic flux switching permanent magnet motor according to the present invention; and Fig. 2 is a single module schematic of a magnetic flux switching permanent magnet motor according to the present invention. As shown in the figure, the magnetic flux switching type permanent magnet motor of the present invention includes a motor stator 110 and a motor rotor 120. The motor stator 110 surrounds the motor rotor 120.

Continuing, the motor stator 110 has twelve stator tooth poles 111, and a permanent magnet 130 is inserted in each of the stator tooth poles 111. One surface of each stator tooth pole 111 corresponds to a permanent surface corresponding to one of the adjacent stator tooth poles 111. The magnets 130 have the same magnetic properties, and the two adjacent stator tooth poles 111 are spaced by tooth grooves 112. The motor rotor 120 has ten rotor poles 121. The stator tooth pole 111 may be made of silicon steel sheet.

Among them, the motor stator 110 and the motor rotor 120 meet the following conditional expressions:

b _i = 0.1545T _s (2)

S = R _si / R _so = 0.618 (3)

b _p = 0.4045T _s (4)

b _h = 0.5T _s (5)

Among them, b _m is the thickness of the permanent magnet, b _t is 1/2 of the width of the stator tooth poles excluding the permanent magnets, b _s is the width of the cogging grooves, and b _i is the thickness of the stator yoke of the stator tooth poles, b _p is the width of the rotor pole, b _h is the height of the rotor pole, R _si is the inner diameter of the motor stator, R _so is the outer diameter of the motor stator, S is the ratio of the inner and outer diameter of the motor stator, and T _s is the tooth of the stator tooth Slot pitch.

As shown in FIG. 1, in addition to the tooth grooves 112, the stator tooth poles 111 and the stator tooth poles 111 have a stator yoke 113. Each stator yoke 113 corresponds to the tooth groove 112 and connects adjacent stator teeth.极 111。 The pole 111.

Furthermore, as shown in FIG. 2, the portion 131 of the permanent magnet corresponding to the stator yoke may be replaced with a non-magnetic material, and the thickness of the portion 131 of the permanent magnet corresponding to the stator yoke may not be greater than the thickness of the stator yoke 113.

In addition, there may be an air gap between the motor stator 110 and the motor rotor 120; the width of the air gap may be the inner diameter of the motor stator 110 minus the outer diameter of the motor rotor 120.

Please refer to FIG. 1 again. Each stator tooth pole 111 has a coil winding, and the 12 stator tooth poles 111 are divided into three phases of A, B, and C. Each phase includes four stator tooth poles 111, and the coil also has three phases. The coils of each phase are wound with 4 stator tooth poles 111 of the corresponding phase, and the coils of the stator tooth poles 111 of the phase can be connected in series or in parallel with each other; Number of coil turns.

Please refer to FIG. 3, which is a magnetic field line distribution diagram of the magnetic flux switching type permanent magnet motor of the present invention. The magnetic flux switching type permanent magnet motor of the present invention makes the outer diameter of the 12/10 FSPM motor 60mm, the coil current of each phase is 3.536 amps (the peak is 5 amps), the stator tooth poles are wound with 30 turns per tooth pole, and the accumulated thickness is 30mm According to the design of conditional expressions (1) to (5), the motor is operated at rated load. When the maxwell finite element electromagnetic analysis software is used to run at 1200 revolutions per minute, the simulated magnetic field line distribution state (such as the third As shown).

Continuing, the position of the rotor pole 121 'in Fig. 3 (a) is 0 °, and the area corresponding to the stator tooth poles is the largest, so that the positive magnetic flux is the largest; the position of the rotor pole 121' in Fig. 3 (b) is 9 ° , Which does not correspond to the stator tooth poles, and thus the magnetic flux is 0; in FIG. 3 (c), the rotor pole 121 ′ is located at 18 °, which corresponds to the other stator tooth poles. The area of the part is the largest, and the negative magnetic flux is the largest. In Figure 3 (d), the rotor pole 121 'is located at 27 °, which does not correspond to the stator tooth pole, and the magnetic flux is 0. It can be known that in the mechanical angle conversion of the rotor pole 121, a loop is generated every 36 ° of magnetic flux, and the electrical angle corresponding to the mechanical angle of 9 ° is 90 °. Among them, the color red to green indicates that the magnetic flux intensity is strong to weak, red is the strongest and green is the weakest.

Please refer to FIG. 4, which is a waveform diagram of the opposite electromotive force of the flux-switching permanent magnet motor of the present invention. In the present invention, S is 0.618, and the corresponding opposite electromotive force is shown in Fig. (A); while, in Fig. 4 (b), when S = 0.37, the waveform of the opposite electromotive force will contain multiple low and high order harmonics. Compared with (a), the wave has obvious serious distortion. When the design is changed so that S is 0.6285, the waveform of the opposite electromotive force is closer to Fig. 4 (c). It can be seen that it is close to the motor stator defined by the present invention. In contrast to the design of the motor rotor, the waveform of the electromotive force will be closer to the sine fundamental wave.

Please refer to FIG. 5, which is an electromagnetic torque waveform diagram of the magnetic flux switching permanent magnet motor of the present invention. In the present invention, S is set to 0.618. The simulated electromagnetic torque waveform at 1200 rpm is shown in Figure 5 (a). The simulated average electromagnetic torque is 3.2349 Nm; and S is 0.37. At the time, the simulated electromagnetic torque waveform at 1200 rpm is shown in Figure 5 (b). The simulated average electromagnetic torque is 2.7018Nm, which is significantly reduced by 16.48%, and the electromagnetic torque ripple The wave has also increased significantly; if S is changed to 0.6285, the motor stator and rotor structure remain unchanged, and the same is run at rated load. The simulated electromagnetic torque waveform at 1200 rpm is shown in Figure 5. As shown in (c), the average electromagnetic torque obtained by the simulation is 3.0231 Nm, the average electromagnetic torque is only reduced by 6.55%, and the electromagnetic torque ripple is slightly improved.

Continuing, because S = 0.6285 is closer to the design of conditional expression (3), the average electromagnetic torque is only reduced by 6.55%, and the electromagnetic torque ripple is also slightly improved. Conversely, when S = 0.37, partial The design of conditional expression (3) is more, and the average electromagnetic torque will be greatly reduced by 16.48%, and the electromagnetic torque ripple will also increase significantly.

As mentioned above, the magnetic flux switching type permanent magnet motor of the present invention has a structure design of 12 stator tooth poles and 10 rotor poles, and a permanent magnet is inserted into the stator tooth poles, so that the magnetic flux switching type permanent magnet of the present invention The magnetic motor can simplify the complicated design of the conventional motor, and can effectively reduce the sudden torque and torque ripple of the conventional motor.

The above-mentioned embodiments are only for explaining the technical ideas and characteristics of the present invention. The purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. When the scope of the patent of the present invention cannot be limited, That is, any equivalent changes or modifications made in accordance with the spirit disclosed in the present invention should still be covered by the patent scope of the present invention.

110‧‧‧Motor stator

111‧‧‧Stator tooth pole

112‧‧‧Groove

113‧‧‧Stator yoke

120‧‧‧motor rotor

121‧‧‧rotor pole

130‧‧‧ permanent magnet

Claims (5)

A magnetic flux switching type permanent magnet motor includes: a motor stator having twelve stator tooth poles, a permanent magnet is inserted in each of the stator tooth poles, and one surface of each of the stator tooth poles is adjacent to the stator teeth. The magnets corresponding to one surface of the poles have the same magnetic properties as the permanent magnets, and the two adjacent ones have a tooth gap between the tooth poles; and a motor rotor with ten rotor poles; wherein the motor stator and the motor rotor meet the following conditions: formula: b _i = 0.1545T _s ; S = R _si / R _so = 0.618 ; b _p = 0.4045T _s ; and b _h = 0.5T _s ; where b _m is the thickness of the permanent magnet and b _t is not included 1/2 width of the stator tooth pole of the permanent magnet, b _s is the width of the cogging, b _i is the thickness of a stator yoke of the stator tooth pole, b _p is the width of the rotor pole, b _h is the height of the rotor pole, R _si is the inner diameter of the motor stator, R _so is the outer diameter of the motor stator, S is the ratio of the inner and outer diameter of the motor stator, and T _s is the stator tooth pole Cogging pitch. According to the magnetic flux switching type permanent magnet motor described in item 1 of the scope of patent application, wherein each of the stator tooth poles is connected by the stator yoke, and each of the stator yoke systems corresponds to a cogging. The magnetic flux switching permanent magnet motor according to item 2 of the scope of the patent application, wherein the part of the permanent magnet corresponding to the stator yoke is replaced with a non-magnetic material. The magnetic flux switching type permanent magnet motor according to item 1 of the patent application scope, wherein an air gap is provided between the motor stator and the motor rotor. The magnetic flux switching permanent magnet motor as described in item 4 of the scope of patent application, wherein the width of the air gap is the inner diameter of the motor stator minus the outer diameter of the motor rotor.