Double-armature excitation type doubly salient permanent magnet motor

Abstract

The utility model relates to a double-armature excitation type doubly salient permanent magnet motor. The utility model is suitable for the technical field of motors. The technical problem to be solved by the utility model is to provide a double-armature excitation type doubly salient permanent magnet motor. According to the technical scheme, the double-armature excitation type double-salient-pole permanent magnet motor is characterized by comprising a stator iron core which is provided with a stator yoke and stator teeth, and a permanent magnet is embedded in the stator yoke; the stator armature winding is arranged on the stator teeth of the stator core; a rotor core having a rotor yoke and rotor teeth; and the rotor armature winding is arranged on the rotor teeth of the rotor core. The number of stator teeth on the stator core is Ns, and Ns = 4ms * k3; the number of rotor teeth on the rotor core is Nr, and Nr = (1 + 2ms) * k3; wherein ms is the phase number of the stator armature winding, ms = 3, and k3 is a positive integer.

Description

Technical Field

[0001] The utility model relates to a double-armature excitation type double-salient-pole permanent magnet motor, which is applicable to the technical field of motors. Background Art

[0002] The doubly salient permanent magnet motor is based on the switched reluctance motor, with one or more pairs of permanent magnets added to the stator yoke. The rotor only has salient pole teeth, which has high mechanical strength. It also has the advantage of high power density of rotor permanent magnet motors and is suitable for electric vehicle drive systems, wind power generation systems, aviation power generation systems and other fields.

[0003] In traditional double-salient permanent magnet motors, most of them have 3 phases of stator armature winding, 6k stator teeth, and 6k±2k rotor teeth, where k is a positive integer. The number of stator teeth between two adjacent permanent magnets is equal to 3, and there is an asymmetry problem in the magnetic circuit of the stator core, which makes the flux linkage and back electromotive force of each phase unbalanced, and the motor has a high torque pulsation.

[0004] In order to solve the problem of magnetic circuit asymmetry of doubly salient permanent magnet motors, a biased flux permanent magnet motor was developed based on the doubly salient permanent magnet motor. The stator and rotor structure of the motor is similar to that of the doubly salient permanent magnet motor, but the number of stator core teeth between two adjacent permanent magnets is 1. This structural design enables the biased flux permanent magnet motor to have a symmetrical magnetic circuit, thereby eliminating the imbalance of phase flux and opposite potential and improving the torque performance of the motor. Although the motor structure can make the magnetic circuit symmetrical, it has disadvantages such as large amount of permanent magnets and poor utilization.

[0005] In the existing improved double-salient-pole motor structure, the number of phases of the stator armature winding is still 3, but the adjacent permanent magnets are separated by two stator teeth to alleviate this problem. For example, the Chinese patent document with publication number CN104821668A discloses a new type of stator permanent magnet motor, including: a rotor and a stator, characterized in that 12n stator salient pole teeth are evenly distributed on the stator, 7n rotor salient pole teeth are evenly distributed on the rotor, and there is an air gap between the stator salient pole teeth, n is an integer, n≥1; on the yoke of the stator, a permanent magnet is provided for every 2 stator salient pole teeth, and the permanent magnets are all tangentially magnetized, and the magnetization directions of two adjacent permanent magnets are opposite; a concentrated armature winding is placed on each stator salient pole tooth, and the phase sequence of the three-phase winding on the stator salient pole tooth is AX, AX, BY, BY, CZ, CZ (such as Figure 1 As shown). Compared with the traditional double-salient permanent magnet motor and biased flux permanent magnet motor, the above structure has better permanent magnet utilization efficiency, can generate symmetrical, bipolar phase flux and highly sinusoidal back electromotive force, and has smooth torque output capability.

[0006] However, compared with the rotor permanent magnet motor, the torque density of the three-phase double salient permanent magnet motor with two adjacent permanent magnet stator teeth is still relatively small. In addition, the motor only uses one set of stator armature windings. When the stator armature winding fails, the motor will not be able to operate. Utility Model Content

[0007] The technical problem to be solved by the utility model is: in view of the above existing problems, a double-armature excitation type double-salient-pole permanent magnet motor is provided.

[0008] The technical solution adopted by the utility model is: a double-armature excitation type double-salient pole permanent magnet motor, characterized in that it includes:

[0009] The stator core comprises a stator yoke and stator teeth, wherein the stator yoke is embedded with permanent magnets;

[0010] A stator armature winding is arranged on the stator teeth of the stator core;

[0011] A rotor core having a rotor yoke and rotor teeth;

[0012] The rotor armature winding is arranged on the rotor teeth of the rotor core.

[0013] The number of stator teeth on the stator core is N s ,

[0014] N s =4m s ×k3;

[0015] The number of rotor teeth on the rotor core is N r ,

[0016] N r =(1+2m s )×k3;

[0017] Among them, m s is the phase number of the stator armature winding, m s =3, k3 is a positive integer.

[0018] The permanent magnet is embedded in the stator yoke at one radial end of the stator core, and the other radial end is located in the stator slot between two adjacent stator teeth of the permanent magnet.

[0019] Magnetic focusing teeth are arranged on both sides of the permanent magnet.

[0020] The stator tooth root is bent along the inner side of the stator yoke in a direction away from the permanent magnet, so that the areas of all stator slots on the stator core are equal.

[0021] The number of permanent magnets on the stator core is half the number of stator teeth on the stator core, and adjacent permanent magnets are spaced apart by two stator teeth.

[0022] The permanent magnets are all tangentially magnetized, and the magnetization directions of two adjacent permanent magnets are opposite.

[0023] The number of phases of the rotor armature winding is m r is 7.

[0024] The beneficial effect of the utility model is as follows: the utility model sets a set of stator armature windings in the stator slots of the stator core, and sets a set of rotor armature windings in the rotor slots of the rotor core. Both sets of windings can pass current to excite the magnetic field, and output torque by acting with the permanent magnetic field, which significantly improves the torque output capacity. When one set of armature windings fails, the other set of armature windings can still interact with the permanent magnet to generate torque, and the motor can still run, which has fault-tolerant characteristics.

[0025] The number of stator teeth on the stator core in the utility model is N s =4m s ×k3, the number of rotor teeth on the rotor core N r =(1+2m s )×k3,m s Take 3, the number of permanent magnets is half the number of stator core teeth, the number of stator teeth between adjacent permanent magnets is 2, the relative position relationship between stator teeth and permanent magnets is consistent, and the permanent magnet magnetic circuit is symmetrical. The current combination maximizes the number of cogging torque cycles and can obtain a smaller cogging torque amplitude. The number of rotor teeth is selected as N r =(1+2m s )×k3, so that the two coils with a phase difference of 180° electrical angle are connected in reverse, all even harmonics in the two coils can be completely offset, so that there are no even harmonics in the phase winding, and highly sinusoidal phase flux and reverse electromotive force are obtained.

[0026] In the utility model, one radial end of the permanent magnet in the stator core is embedded in the stator yoke, and the other end is located in the stator slot surrounded by the stator teeth and the stator yoke, and magnetic concentrating teeth are provided on both sides of the permanent magnet, thereby breaking the constraint of the stator yoke on the radial thickness of the permanent magnet, and can improve the strength of the permanent magnetic field by increasing the amount of permanent magnets, and improve the material utilization efficiency of the stator yoke. The magnetic concentrating teeth are provided on both sides of the permanent magnet to further increase the permanent magnetic field and reduce leakage magnetic flux. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the prior art.

[0028] Figure 2 This is a schematic diagram of the structure of Example 1.

[0029] Figure 3 This is a schematic diagram of the structure of Example 2.

[0030] Figure 4 This is a schematic diagram of the structure of Example 3.

[0031] Figure 5 This is a schematic diagram of the structure of Example 4.

[0032] Figure 6 This is a comparison diagram of the electromagnetic torque waveforms of the motor of the present invention and the existing motor.

[0033] 1. Stator core;

[0034] 11. stator teeth; 12. stator yoke;

[0035] 2. Rotor core;

[0036] 21. rotor teeth; 22. rotor yoke;

[0037] 3. Rotating shaft;

[0038] 4. Permanent magnet;

[0039] 5. Stator armature winding;

[0040] 6. Rotor armature winding. DETAILED DESCRIPTION

[0041] Embodiment 1: This embodiment is a dual-armature excitation type double-salient pole permanent magnet motor, including a stator, a rotor and a shaft, wherein the stator and the rotor are both salient pole structures, the stator is arranged outside the rotor, the stator is a fixed part, and the rotor is a rotating part.

[0042] In this example, the stator includes a stator core, permanent magnets and a stator armature winding. The stator core includes stator teeth and a stator yoke. A plurality of permanent magnets are evenly embedded on the stator yoke. The number of permanent magnets is half the number of teeth of the stator core. Adjacent permanent magnets are separated by two stator teeth. The permanent magnets are magnetized tangentially along the circumference of the stator, and the magnetization direction changes alternately along the circumference tangentially. The stator armature winding is arranged on each stator tooth.

[0043] In this embodiment, the rotor includes a rotor core and a rotor armature winding. The rotor core includes rotor teeth and a rotor yoke. The rotor armature winding is arranged on each rotor tooth.

[0044] In this example, the number of stator teeth on the stator core is N s , the number of rotor teeth on the rotor core is N r , the number of permanent magnets on the stator core is N m , stator armature winding phase number m s =3, the number of phases of the rotor armature winding is m r is 7, which satisfies: N s =k1×m s ×HCF(N s ,N r ), N r=k2×m r ×HCF(N r ,N m / 2), where k1 and k2 are both positive integers, and HCF is the greatest common divisor function.

[0045] In this embodiment, the number of stator teeth N of the stator core is s =4m s ×k3, the number of rotor teeth of the rotor core N r =(1+2m s )×k3, where k3 is a positive integer.

[0046] like Figure 2 As shown, in this example, k3=1, the number of stator teeth is 12, the number of rotor teeth is 7, the number of stator phases of the motor is 3, and the number of stator teeth between adjacent permanent magnets is 2. The stator core is divided into six "π"-shaped stator core segments by six permanent magnets.

[0047] In this embodiment, the armature winding is installed in the rotor slot space without changing the original motor volume and structure, so that the motor has two sets of windings, the stator and the rotor. The rotor armature winding adopts a concentrated winding to maximize the pitch coefficient of the coil.

[0048] Example 2: Figure 3 As shown, the structure of this embodiment is basically the same as that of embodiment 1, and the only difference is that in this embodiment, one radial end of the permanent magnet in the stator core is embedded in the stator yoke, and the other radial end is placed in the stator slot surrounded by two adjacent stator teeth on the left and right of the permanent magnet and the stator yoke.

[0049] This embodiment increases the effective stator slot area by extending the permanent magnet into the stator slot, which is beneficial to increase the conductor cross-sectional area, reduce the stator winding resistance, and increase the current allowed to pass, thereby further improving the torque density of the motor. In addition, magnetic concentrators are arranged on both sides of the permanent magnet, so that the magnetic flux of the permanent magnet first passes through the magnetic concentrators to the stator yoke, and then passes through the stator teeth, and is linked with all the turns of the stator armature winding wound on the stator teeth, which is beneficial to reduce leakage magnetic flux.

[0050] Example 3: Figure 4 As shown, the structure of this embodiment is basically the same as that of embodiment 2, and the only difference is that in this embodiment, the root of the stator tooth is bent along the inner side of the stator yoke away from the permanent magnet, so that the areas of all stator slots are equal, the effective stator slot area is further increased, and the output torque capacity is further enhanced.

[0051] Example 4: Figure 5 As shown, this embodiment is a dual-armature excitation double-salient pole permanent magnet motor, including a stator, a rotor and a shaft, wherein the stator and the rotor are both salient pole structures, the stator is arranged inside the rotor, the stator is a fixed part, and the rotor is a rotating part.

[0052] In this example, the stator includes a stator core, permanent magnets and a stator armature winding. The stator core includes stator teeth and a stator yoke. A plurality of permanent magnets are evenly embedded on the stator yoke. The number of permanent magnets is half the number of teeth of the stator core. Adjacent permanent magnets are separated by two stator teeth. The stator armature winding is arranged on each stator tooth.

[0053] In this embodiment, the rotor includes a rotor core and a rotor armature winding. The rotor core includes rotor teeth and a rotor yoke. The rotor armature winding is arranged on each rotor tooth.

[0054] In this example, the number of stator teeth on the stator core is N s , the number of rotor teeth on the rotor core is N r , the number of permanent magnets on the stator core is N m , stator armature winding phase number m s =3, the number of phases of the rotor armature winding is m r is 7, which satisfies: N s =k1×m s ×HCF(N s ,N r ), N r =k2×m r ×HCF(N r ,N m / 2), where k1 and k2 are both positive integers, and HCF is the greatest common divisor function.

[0055] In this embodiment, the number of stator teeth N of the stator core is s =4m s ×k3, the number of rotor teeth of the rotor core N r =(1+2m s )×k3, where k3 is a positive integer.

[0056] The motor of the present invention and the existing motor of the same size are selected for comparative testing, and a steady-state electromagnetic torque waveform comparison diagram is obtained under the conditions of optimal size parameters and the same copper loss, as shown in FIG. Figure 6 As shown, compared with the existing motors, the average electromagnetic torque of the motor of the present invention is increased by about 70%.

[0057] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A double-armature excitation type double-salient-pole permanent magnet motor, characterized in that: include: The stator core comprises a stator yoke and stator teeth, wherein the stator yoke is embedded with permanent magnets; A stator armature winding is arranged on the stator teeth of the stator core; A rotor core having a rotor yoke and rotor teeth; A rotor armature winding is arranged on the rotor teeth of the rotor core; The number of stator teeth on the stator core is N s , N s =4m s ×k3; The number of rotor teeth on the rotor core is N r , N r =(1+2m s )×k3; Among them, m s is the phase number of the stator armature winding, m s =3, k3 is a positive integer.

2. The dual armature excitation type double salient pole permanent magnet motor according to claim 1, characterized in that: The permanent magnet is embedded in the stator yoke at one radial end of the stator core, and the other radial end is located in the stator slot between two adjacent stator teeth of the permanent magnet.

3. The dual armature excitation type double salient pole permanent magnet motor according to claim 1, characterized in that: Magnetic focusing teeth are arranged on both sides of the permanent magnet.

4. The dual armature excitation type double salient pole permanent magnet motor according to claim 2 or 3, characterized in that: The stator tooth root is bent along the inner side of the stator yoke in a direction away from the permanent magnet, so that the areas of all stator slots on the stator core are equal.

5. The dual armature excitation type double salient pole permanent magnet motor according to claim 1, characterized in that: The number of permanent magnets on the stator core is half the number of stator teeth on the stator core, and adjacent permanent magnets are spaced apart by two stator teeth.

6. The dual armature excitation type double salient pole permanent magnet motor according to claim 5, characterized in that: The permanent magnets are all tangentially magnetized, and the magnetization directions of two adjacent permanent magnets are opposite.

7. The dual armature excitation type double salient pole permanent magnet motor according to claim 1, characterized in that: The number of phases of the rotor armature winding is m r is 7.

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