Fractional slot concentrated winding, stator and fault-tolerant motor

Abstract

The utility model discloses a fractional slot concentrated winding, a stator and a fault-tolerant motor, which comprise coils arranged in stator slots, the pitch of the coils is 1, the coils comprise working coils and backup coils, the working coils and the backup coils are distributed at intervals, and the working coils and the backup coils are sequentially arranged left and right. According to the fractional-slot concentrated winding structure, the coils can be uniformly distributed to each stator tooth, the coil inserting difficulty is reduced, the utilization rate of the stator slots is improved, and the copper loss of a fault-tolerant motor is reduced. Moreover, the working coil and the backup coil are arranged left and right, and the isolation space is increased compared with the vertical arrangement, so that the thermal isolation between the two sets of windings is increased, and the reliability of the fault-tolerant motor is further improved.

Description

Technical Field

[0001] The utility model belongs to the field of electric motors, in particular to a fractional slot concentrated winding, a stator and a fault-tolerant motor. Background Art

[0002] A permanent magnet synchronous motor is an electric motor whose rotor is provided with a magnetic field by a permanent magnet. Due to its advantages such as high power density and high efficiency, it is widely used in military fields such as aerospace, weapons and equipment. In special fields, higher requirements are also placed on the reliability of motors. At present, the most widely used fault tolerance mode is winding backup fault tolerance. The traditional single-layer fractional slot concentrated winding has a structure of tooth-interval winding, large self-inductance and small mutual inductance, so it is widely used in backup fault tolerance. Figure 1 As shown in the figure, in the backup fault-tolerant structure, the working winding and the backup winding are located in the same slot. The disadvantages of this structure are:

[0003] 1) It is difficult to go offline.

[0004] 2) The working winding is in close contact with the backup winding, and the thermal isolation is poor. The motor winding failure is almost always caused by the destruction of the winding insulation caused by heat.

[0005] 3) The stator slot utilization rate is low and the motor heat load is large, which will increase the motor failure rate. Summary of the invention

[0006] The utility model aims to provide a fractional slot concentrated winding, a stator and a fault-tolerant motor, so as to solve the technical problems of the existing backup fault-tolerant structure being difficult to be offline, poor in thermal isolation and low in slot utilization.

[0007] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0008] A fractional slot concentrated winding comprises a coil arranged in a stator slot, wherein the pitch of the coil is 1, the coil comprises a working coil and a backup coil, the working coil and the backup coil are distributed at intervals, and the working coil and the backup coil are arranged left and right in sequence.

[0009] Furthermore, each of the stator slots has two coil sides.

[0010] Furthermore, the two coil sides are respectively connected to the working coil and the backup coil.

[0011] Furthermore, the working coil and the backup coil are arranged to form a three-phase rotating motor winding, the working coil constitutes a working winding, and the backup coil constitutes a backup winding.

[0012] A stator comprises a stator core and a winding, wherein the winding is the fractional slot concentrated winding.

[0013] Furthermore, the stator slots are arranged on the stator core.

[0014] Furthermore, the number of the stator slots is an even multiple of 3.

[0015] Furthermore, the stator core is provided with stator teeth, and the working coil and the backup coil are both wound around the stator teeth.

[0016] A fault-tolerant motor comprises the stator.

[0017] Furthermore, it comprises two sets of position detection devices, and the two sets of position detection devices correspond to one side of the working coil and the backup coil respectively.

[0018] Compared with the prior art, the utility model has the following beneficial effects:

[0019] The utility model provides a fractional slot concentrated winding. According to the arrangement characteristics of the single-layer fractional slot concentrated winding, by changing the winding structure, the working winding and the backup winding are arranged left and right, and the pitch of the coil is 1, and there is a coil on each stator tooth. Each set of winding arrangement meets the basic requirements of a three-phase rotating motor, so when the two sets of windings work alone, the output characteristics of the fault-tolerant motor will not be changed. The fractional slot concentrated winding structure of the utility model can evenly distribute the coil to each stator tooth, reduce the difficulty of offline, improve the utilization rate of the stator slot, and reduce the copper loss of the fault-tolerant motor. Moreover, the working coil and the backup coil are arranged left and right, and the isolation space is increased compared to the upper and lower arrangement, which helps to increase the thermal isolation between the two sets of windings, reduce the thermal load of the fault-tolerant motor, thereby reducing the failure rate of the fault-tolerant motor and further improving the reliability of the fault-tolerant motor.

[0020] Furthermore, position detection devices are respectively provided on one side of the working coil and the backup coil, and the working winding and the backup winding work independently, and switching operation will not affect the normal operation of the fault-tolerant motor system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 This is a schematic diagram of the traditional backup fault-tolerant structure.

[0023] Figure 2 This is a schematic diagram of the backup fault-tolerant structure of the utility model.

[0024] Figure 3 This is a no-load back electromotive force simulation diagram of the fractional-slot concentrated winding of the utility model.

[0025] Figure 4 This is a simulation diagram of the magnetic field distribution of the fractional-slot concentrated winding of the present utility model.

[0026] Figure 5 This is a torque simulation diagram of the fractional-slot concentrated winding of the utility model.

[0027] Among them: 1-stator core, 2-winding;

[0028] Figure 3 (a) is the no-load back EMF simulation diagram of the working winding. Figure 3 (b) is the no-load back EMF simulation diagram of the backup winding; Figure 4 (a) is the simulation diagram of magnetic field distribution of working winding. Figure 4 (b) is a simulated diagram of the magnetic field distribution of the backup winding; Figure 5 (a) is the torque simulation diagram of the working winding. Figure 5 (b) is the torque simulation diagram of the backup winding. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0032] In the description of the embodiments of the present utility model, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the utility model product is usually placed when in use, it is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0033] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0034] In the description of the embodiments of the present utility model, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0035] The utility model is further described in detail below with reference to the accompanying drawings:

[0036] See also Figure 2 The utility model provides a fractional slot concentrated winding, including a working winding and a backup winding, and the span of the working winding and the backup winding is 1.

[0037] The working winding and the backup winding are respectively provided with a working coil and a backup coil, and the coils are both arranged in the stator slots. The working coil and the backup coil are arranged in sequence on the left and right and spaced apart. The pitch of the coil is 1, that is, the number of stator slots spanned between the two effective sides of the coil is 1. There are two coil sides in each stator slot, and the two coil sides are respectively connected to the working coil and the backup coil. Each coil is wound on the stator teeth, and the coil ends in the same stator slot do not contact, which effectively realizes thermal isolation and avoids damage to the insulating material. The arrangement of the working coil and the backup coil meets the basic requirements of the three-phase rotating motor. The two sets of windings of the working coil and the backup coil can be switched and operated without affecting the operation of the system.

[0038] The utility model also provides a stator, comprising a stator core 1 and a winding 2, wherein the winding 2 is the above-mentioned fractional slot concentrated winding. The stator slots are arranged on the stator core 1, and Z / 3 is an even number (Z is the number of stator slots). The stator core 1 is provided with stator teeth, and the working coil and the backup coil are both wound on the stator teeth.

[0039] The utility model also provides a fault-tolerant motor, comprising the above-mentioned stator, wherein the fault-tolerant motor has Z coils, wherein the working coil and the backup coil each account for half.

[0040] If two sets of position detection devices are provided in the fault-tolerant motor, corresponding to one side of the working coil and the backup coil respectively, the working winding and the backup winding work independently, and the switching operation will not affect the system operation.

[0041] If the fault-tolerant motor adopts the position sensorless control mode, when the two sets of windings are switched, the torque and direction are kept unchanged by adjusting the current phase and angle.

[0042] The principle of the fractional slot concentrated winding of the utility model is:

[0043] According to the characteristics of single-layer fractional slot concentrated winding, the traditional two sets of windings arranged up and down in the same stator slot are changed to be arranged left and right in the same stator slot, and each stator tooth has a winding. And each set of winding arrangement meets the basic requirements of three-phase rotating motors, so when the two sets of windings work alone, the output characteristics of the fault-tolerant motor will not be changed. By changing the winding arrangement, this winding structure can reduce the difficulty of processing, improve the utilization rate of the stator slot and the reliability of the fault-tolerant motor.

[0044] The following is a finite element calculation to further illustrate the characteristics of the fractional slot concentrated winding of the utility model:

[0045] like Figure 3 As shown in the figure, from the comparison of the no-load back EMF of the working winding and the backup winding, it can be seen that the no-load back EMF of the working winding and the backup winding are three-phase symmetrical. There is a phase difference between the no-load back EMF of the two sets of windings, which is caused by the angle between the two sets of windings in space.

[0046] If each set of windings has an independent position detection unit, the back-EMF phase difference will not affect the use of the fault-tolerant motor.

[0047] like Figure 4 As shown in the figure, the magnetic field distribution comparison of the working winding and the backup winding shows that when the working winding and the backup winding work separately, the stator magnetic field will be offset. The magnetic field formed by each set of windings is the same and can provide the torque required for the fault-tolerant motor to rotate continuously.

[0048] If each set of windings has an independent position detection device, the switching operation of the two sets of windings will not affect the operation of the fault-tolerant motor system;

[0049] If the fault-tolerant motor adopts the position sensorless control mode, when the two sets of windings are switched, the phase and angle of the phase current can be adjusted to achieve unchanged torque and direction.

[0050] like Figure 5 As shown, from the torque comparison of the working winding and the backup winding, it can be seen that the output torque of the two sets of windings is the same when they work alone.

[0051] The utility model takes a 12-slot concentrated winding motor as an example for explanation, but the application is not limited to the 12-slot motor. All pole-slot combinations of single-layer fractional-slot concentrated windings are protected by this patent.

[0052] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be subject to various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A fractional slot concentrated winding, characterized in that: It includes a coil arranged in a stator slot, the pitch of the coil is 1, the coil includes a working coil and a backup coil, the working coil and the backup coil are distributed at intervals, and the working coil and the backup coil are arranged left and right in sequence.

2. The fractional slot concentrated winding according to claim 1, characterized in that: Each of the stator slots has two coil sides.

3. The fractional slot concentrated winding according to claim 2, characterized in that: The two coil sides are respectively connected to the working coil and the backup coil.

4. The fractional slot concentrated winding according to claim 1, characterized in that: The working coil and the backup coil are arranged to form a three-phase rotating motor winding, the working coil constitutes a working winding, and the backup coil constitutes a backup winding.

5. A stator, characterized in that: The invention comprises a stator core (1) and a winding (2), wherein the winding (2) is the fractional-slot concentrated winding according to any one of claims 1 to 4.

6. A stator according to claim 5, characterized in that: The stator slots are arranged on the stator core (1).

7. A stator according to claim 5, characterized in that: The number of the stator slots is an even multiple of 3.

8. A stator according to claim 5, characterized in that: The stator core (1) is provided with stator teeth, and the working coil and the backup coil are both wound around the stator teeth.

9. A fault-tolerant motor, characterized in that: The invention comprises the stator as claimed in any one of claims 5 to 8.

10. The fault-tolerant motor according to claim 9, characterized in that: It comprises two sets of position detection devices, which are respectively corresponding to one side of the working coil and the backup coil.

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