TWI618332B - 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 a plurality of 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 a plurality of 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 ; b _h = 0.5T _s ; R _r ( θ ) = R _ro - 0.25T _s (1-cos θ ); And R _ro - R _ri = b _h = 0.5T _s ; where b _m is the thickness of the permanent magnet, b _t is 1/2 the width of the stator poles without the permanent magnet, 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, R _si is the inner diameter of the motor stator, R _so is the outer diameter of the motor stator, and S is the outer diameter of the motor stator Internal and external diameter ratio, T _s is the cogging pitch of the stator tooth poles, N _s is the cogging number, R _r is the diameter of the motor rotor, R _ro is the outer diameter of the motor rotor, and R _ri is The inner diameter of the motor rotor.

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‧‧‧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 schematic diagram of the relationship between the diameter and the position of the rotor poles of the magnetic flux switching 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 in conjunction with the drawings in the form of an embodiment, and the drawings used therein, Its main purpose is only for the purpose of illustration and supplementary description. It may not be the actual proportion and precise configuration after the implementation of the invention. Therefore, the attached 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, so it should not be understood to be limited to this The embodiments described herein, on the contrary, to those having ordinary knowledge in the technical field, the embodiments provided will make this disclosure more thoroughly and comprehensively and completely convey the scope of the invention, and the invention will only be appended As defined by the scope of patent applications.

Please refer to Figs. 1 to 3; Fig. 1 is a schematic structural diagram of a magnetic flux switching permanent magnet motor according to the present invention; Fig. 2 is a schematic diagram of a single module of the magnetic flux switching permanent magnet motor according to the present invention; The figure is a schematic diagram of the relationship between the diameter and the position of the rotor poles of the magnetic flux switching permanent magnet motor of 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 includes a plurality of 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)

R _r ( θ ) = R _ro - 0.25T _s (1-cos θ ) (6)

R _ro - R _ri = b _h = 0.5T _s (7)

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, 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 groove pitch, N _s the number of lines for cogging, R _r lines for the path length of the rotor of the motor, R _ro line for the inner diameter of the motor rotor for the outer diameter of the rotor of the motor based R _ri.

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 this phase can be connected in series or Preferably, a series mode can be used at high voltages, and a parallel mode can be used at low voltages, and the number of coil turns can be changed according to demand.

In more detail, the flux-switched permanent magnet motors manufactured according to the design of conditional expressions (1) to (5) have excellent efficiency and high electromagnetic torque. However, the torque and Torque ripple still cannot be ignored; furthermore, in order to make it have the characteristics of low torque and low torque ripple of surface permanent magnet synchronous motor, the width and height of the rotor poles need to be redesigned.

Among them, the area A _s surrounded by a stator slot can be deduced from conditional expression (8):

The phase resistance R _a can also be derived as conditional formula (9):

Among them, m represents the number of phases of the magnetic flux switching permanent magnet motor; N _w represents the number of turns of each phase coil of the magnetic flux switching permanent magnet motor; ρ _Cu is the resistivity of copper; K _s is the slot packing ratio (slot packing factor); L _a is a permanent magnet flux switching motor shaft length; L _e is a permanent magnet flux switching motor end line (ending-winding) the length, as shown in the conditional expression (10):

The torque of the flux-switching permanent magnet motor can be derived from conditional expression (11):

Among them, p represents the number of poles of the rotor pole; λ _m is the magnitude of the magnetic flux connection of the magnet in the d-axis direction of the rotor, which is shown in conditional formula (12): λ _m = B _m b _t L _a N _w (12)

Among them, B _m is the maximum magnetic flux density of the stator silicon steel material.

As shown in Figure 2, based on the design of the width and height of the rotor poles shown in conditional expressions (4) and (5), and then according to the rotor pole position angle, cooperate with conditional expression (6) to make the rotor pole diameter longer. Arc repair action to change the air gap magnetic flux, thereby achieving the purpose of reducing the cogging torque and torque ripple.

However, when the rotor pole position is changed from zero to 360 degrees, as shown in FIG. 3, the rotor pole position is zero degrees, and the rotor diameter R _r ( θ ) is the rotor pole outer diameter R _ro , corresponding to the diameter in FIG. 3. Is the length of +1 unit; while the rotor pole position is 180 degrees, R _r ( θ ) is the rotor pole inner diameter R _ri , which corresponds to the length of the unit in FIG. 3 where the diameter is -1 unit; and the average diameter of the motor rotor is Corresponds to a length of 0 units in the diameter in Figure 3.

As mentioned above, the magnetic flux switching type permanent magnet motor of the present invention has a structure of 12 stator tooth poles, and a permanent magnet is inserted into the stator tooth poles, and the arc repairing design of the rotor poles makes the magnetism of the present invention The switching permanent magnet 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

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

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 side of the poles have the same magnetic properties as the permanent magnets, and the two adjacent stator teeth have a tooth gap; and a motor rotor has a plurality of rotor poles. Among them, the motor stator and the motor rotor are in accordance with the following Conditional: b _i = 0.1545T _s ; S = R _si / R _so = 0.618 ; b _p = 0.4045T _s ; b _h = 0.5T _s ; R _r ( θ ) = R _ro - 0.25T _s (1-cos θ ); And R _ro - R _ri = b _h = 0.5T _s ; where b _m is the thickness of the permanent magnet, b _t is 1/2 the width of the stator tooth poles excluding the permanent magnet, and b _s is The width of the cogging, b _i is the thickness of the stator yoke of one of the stator teeth poles, b _p is the width of the rotor poles, b _h is the height of the rotor poles, and R _si is inside the motor stator. Diameter, R _so is the outer diameter of the motor stator, S is the inner and outer diameter ratio of the motor stator, T _s is the cogging pitch of the stator tooth poles, N _s is the cogging number, and R _r is Is the diameter of the motor rotor, R _ro is the outer diameter of the motor rotor, and R _ri is the inner diameter of the motor rotor. 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.