Modularized magnetic field reinforced rotor structure of alternating current excitation motor

Abstract

The invention, which belongs to the technical field of the AC excitation generator motor, discloses a modularized magnetic field reinforced rotor structure of an AC excitation motor, comprising asymmetric small tooth modules, symmetric small tooth modules, rotor large tooth modules, slot wedges, a rotor yoke part, an inner-layer split concentrated winding and an outer-layer magnetic field reinforced winding. The rotor yoke part is provided with rotor large-tooth modules along the circumferential direction, and an inner-layer split concentrated winding is arranged between the adjacent large-tooth modules; one sides, without tooth tips, of the asymmetric small tooth modules are connected with the slot wedges, and the symmetric small tooth modules are alternately connected with the slot wedges and then are connected with the other asymmetric small tooth module, so that a small tooth-slot wedge combined module is formed; the small tooth-slot wedge combination modules surround the outer side of the rotor yoke part, and the outer layer magnetic field strengthening windings are arranged between the adjacent small tooth-slot wedge combination modules. The motor slot current density is lower through rotor transformation, the pole slot matching is more flexible in selection, the design of low slot current and high air gap magnetic flux density of the motor is realized, and the operation reliability of the large motor is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of alternating current excitation motor applied to variable speed pumped storage unit and the like, and more particularly relates to a modular magnetic field reinforced rotor structure of alternating current excitation motor. BACKGROUND

[0002] To accelerate the green and low-carbon transformation of energy, it is necessary to build a new power system dominated by new energy. Pumped storage is the most mature, most economical and most scalable green and low-carbon flexible regulation power source for power systems, which can effectively alleviate the accommodation problem of large-scale new energy grid connection and is an effective way to improve the safety and stability of new power systems. Compared with the fixed-speed pumped storage technology using synchronous motors, the variable-speed pumped storage using alternating current excitation motors (or called double-fed asynchronous motors) as generators-motors has significant advantages in hydraulic performance, power regulation characteristics and system comprehensive efficiency. By controlling the frequency of rotor current, the mechanical speed of the rotor can be changed to achieve variable speed operation.

[0003] The conventional rotor winding of alternating current excitation motor adopts a distributed structure, i.e. the winding end is too long and difficult to fix, which significantly reduces the reliability of the rotor. The use of fractional slot concentrated winding structure makes it difficult to solve the problem of excessive slot current density. Therefore, it is urgent to develop a new rotor structure to solve the technical problems of excessive slot current density and processing and installation difficulty, which has important theoretical value and practical significance for improving the reliability of the rotor. SUMMARY

[0004] In view of the above defects or improvement needs of the prior art, the present application provides a modular magnetic field reinforced rotor structure of alternating current excitation motor, thereby solving the technical problem of excessive slot current density of the winding.

[0005] To achieve the above-mentioned purpose, according to one aspect of the present application, a modular magnetic field reinforced rotor structure of alternating current excitation motor is provided, comprising: an asymmetric small tooth module, a symmetric small tooth module, a rotor large tooth module, a slot wedge, a rotor yoke, an inner layer split concentrated winding and an outer layer magnetic field strengthening winding; The rotor yoke is provided with a plurality of rotor large tooth modules in the circumferential direction, and a plurality of groups of inner layer split concentrated windings are arranged between adjacent large tooth modules; The non-tooth tip side of the asymmetric small tooth module is connected with the slot wedge, and the other side of the slot wedge is connected with the symmetric small tooth module; a plurality of symmetric small tooth modules and a plurality of slot wedges are alternately connected with another asymmetric small tooth module to form a small tooth-slot wedge combined module; A plurality of small tooth-slot wedge combined modules are arranged around the outer side of the rotor yoke, and the outer layer magnetic field strengthening winding is arranged between adjacent small tooth-slot wedge combined modules.

[0006] Preferably, the rotor big tooth module, the rotor yoke, the asymmetric small tooth module, the slot wedge, the slot wedge and the symmetric small tooth module, the small tooth-slot wedge combination module and the rotor yoke are connected by dovetail slots.

[0007] Preferably, the rotor big tooth module is a rectangular symmetric structure, the inner diameter of which is provided with a dovetail structure for fixing the rotor big tooth module to the rotor yoke; the outer diameter of the rotor big tooth module is provided with a dovetail slot for connecting the asymmetric small tooth module.

[0008] Preferably, one side of the asymmetric small tooth module is a tooth tip-free structure, the other side of which is provided with a dovetail structure for connecting the slot wedge; the other side of the asymmetric small tooth module is a tooth tip structure; the radial direction of the asymmetric small tooth module is a trapezoidal structure with the upper part being wider and the lower part being narrower, and the inner diameter of which is provided with a dovetail structure for connecting the outer diameter of the rotor big tooth module.

[0009] Preferably, the radial direction of the symmetric small tooth module is a trapezoidal structure with the upper part being wider and the lower part being narrower, and both sides of which are provided with a dovetail structure for connecting the slot wedge.

[0010] Preferably, the rotor yoke is provided with a plurality of rotor tooth structures along the circumferential direction, the top of the rotor tooth structure is provided with a dovetail slot; the adjacent rotor tooth structures are provided with a dovetail slot for placing the rotor big tooth module.

[0011] Preferably, the rotor tooth structure is provided with a rectangular slot, and the inner layer split concentrated winding is located in the rectangular slot.

[0012] Preferably, the rotor big tooth module and the rotor yoke are made of high permeability material; the slot wedge is made of non-magnetic material, and both sides of the slot wedge are provided with a dovetail slot for connecting the symmetric small tooth module.

[0013] Preferably, the outer layer magnetic field strengthening winding is a fractional slot concentrated winding structure formed by a forming wire, and the magnetic field direction of the outer layer magnetic field strengthening winding is the same as that of the inner layer split concentrated winding.

[0014] Preferably, the positive and negative sides of the same phase winding of the inner layer split concentrated winding are arranged at the bottom of the rectangular slot, the top of the rectangular slot or the two sides of the rotor big tooth module.

[0015] Overall, compared with the prior art, the above technical solutions conceived by the present application can achieve the following beneficial effects: 1. The modular magnetic field reinforced rotor structure of the alternating current excited motor proposed in the present application is divided into three main parts of rotor small tooth module, rotor large tooth module and rotor yoke part, adopts the method of combining inner layer split type concentrated winding and outer layer fractional slot concentrated winding, and is installed in radial layers, the slot current density of the motor is lower through the transformation of the rotor structure, the pole slot matching is more flexible in selection, the low slot current and high air gap flux density design of the motor are realized, and the operation reliability of the large motor is improved.

[0016] 2. The modular magnetic field reinforced rotor structure of the alternating current excited motor proposed in the present application, the rotor structure adopts modular design, so that the rotor is easier to manufacture and assemble, and the production efficiency is improved; especially in the installation of large motors, modular design can be block hoisted and spliced, realizing the rapid installation of large motors. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is the cross-sectional view of the alternating current excited motor of the magnetic field reinforced rotor structure of the present application; Figure 2 is the schematic diagram of the modular magnetic field reinforced rotor structure of the left and right arrangement of the inner layer split type winding of the present application; Figure 3 is the schematic diagram of the modular magnetic field reinforced rotor structure of the upper and lower arrangement of the inner layer split type winding of the present application; Figure 4 is the partial schematic diagram of the rotor structure of the present application; Figure 5 is the schematic diagram of the asymmetric small tooth module of the present application; Figure 6 is the schematic diagram of the symmetric small tooth module of the present application; Figure 7 is the schematic diagram of the rotor large tooth module of the present application; Figure 8 is the schematic diagram of the slot wedge of the present application; Figure 9 is the schematic diagram of the rotor yoke part of the present application; Figure 10 is the schematic diagram of the rotor asymmetric small tooth, symmetric small tooth module and slot wedge combination module of the present application; Figure 11 is the schematic diagram of the rotor module embedded with distributed winding of the present application; Figure 12 is the three-dimensional distribution diagram of the inner layer split type winding of the present application; Figure 13 is the assembly drawing of the upper and lower arrangement of the inner layer split type winding embedded in the rotor yoke part of the present application.

[0018] In all the drawings, the same reference signs are used to denote the same elements or structures, wherein: 1, stator; 2-1, asymmetric cog module; 2-2, symmetric cog module; 3, rotor cog module; 4, slot wedge; 5, rotor yoke; 6, inner layer split concentrated winding; 7, outer layer field strengthening winding. DETAILED DESCRIPTION

[0019] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely used to explain the present application and should not be used to limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0020] As shown in Figure 1 , the present application proposes an alternating current excited motor modular magnetic field strengthening rotor structure, which comprises asymmetric cog modules 2-1, symmetric cog modules 2-2, rotor cog modules 3, slot wedges 4, rotor yokes 5, inner layer split concentrated windings 6 and outer layer field strengthening windings 7. First, the tooth tip-free side of the asymmetric cog module 2-1 is connected with the slot wedge 4, and the other side of the slot wedge 4 is connected with the symmetric cog module 2-2. Next, the symmetric cog module 2-2 and the slot wedge 4 are alternately connected, and finally connected with another asymmetric cog module 2-1, forming a cog-slot wedge combination module. The outer layer field strengthening winding 7 is wound on the cog-slot wedge combination module. The rotor cog module 3 is connected with the rotor yoke 5, and the inner layer split concentrated winding 6 is made in the slot formed by the rotor cog module 3 and the rotor yoke 5. Finally, the cog-slot wedge combination module with the wound winding is connected with the rotor cog module 3 and the rotor yoke 5 to form the alternating current excited motor modular magnetic field strengthening rotor structure. The inner layer split concentrated winding 6 and the outer layer field strengthening winding 7 belong to runway type formed windings, which are sleeved on each corresponding cog-slot wedge combination rotor module, and the inner layer split winding and the field strengthening winding do not overlap.

[0021] Further explanation, as shown in Figure 2 , the outer layer field strengthening winding 7 adopts a formed coil, which is a fractional slot concentrated winding structure. The winding directly connected with the yoke adopts an inner layer split winding structure. The inner and outer two sets of windings are arranged in an upper and lower manner without overlapping parts. The formed coil of the inner layer split winding is arranged on the positive and negative sides of the same phase winding in a left and right manner on both sides of the cog. Further explanation, as shown in Figure 3 , the formed coil of the inner layer split concentrated winding 6 can also be arranged on the positive and negative sides of the same phase winding at the bottom and top of the slot.

[0022] Further explanation, as shown in Figure 4As shown, the two pinion modules are connected with the slot wedge through dovetail grooves, the pinion and the big tooth, the pinion and the yoke, and the big tooth and the yoke are connected through the big dovetail groove.

[0023] Further explanation, as shown in Figure 5 As shown, the asymmetric pinion module 2-1 has a tooth tip structure on one side and no tooth tip structure on the other side. The side connected with the slot wedge 4 adopts the structure without tooth tip, and the other side adopts the structure with tooth tip. The side without tooth tip of the asymmetric pinion module 2-1 adopts a small dovetail structure cut by wire, and the asymmetric pinion module 2-1 adopts a trapezoidal structure with the upper part wide and the lower part narrow in the radial direction. A larger dovetail structure is arranged at the inner diameter for fixing with the rotor big tooth module 3.

[0024] Further explanation, as shown in Figure 6 As shown, the symmetric pinion module 2-2 adopts a trapezoidal structure with the upper part wide and the lower part narrow, and both sides have a small dovetail structure for connecting with the slot wedge 4.

[0025] Further explanation, as shown in Figure 7 As shown, the rotor big tooth module 3 adopts a rectangular symmetric structure. A dovetail structure is designed at the inner diameter of the silicon steel sheet by wire cutting, and a dovetail groove is opened at both ends of the outer diameter by the same method. The processed silicon steel sheets are stacked and welded to form the rotor big tooth module 3.

[0026] Further explanation, as shown in Figure 8 As shown, the slot wedge 4 is made of non-magnetic material, and has a trapezoidal structure with the upper part narrow and the lower part wide. The slot wedge 4 has a shallow dovetail structure groove on both sides, which cooperates with the dovetail structure on the side without tooth tip of the asymmetric pinion module 2-1.

[0027] Further explanation, as shown in Figure 9 As shown, the rotor yoke 5 has a plurality of groups of rotor tooth structures distributed in the circumferential direction, and the middle part of the two groups of rotor tooth structures is provided with a dovetail groove structure.

[0028] Further explanation, as shown in Figure 10 As shown, the side without tooth tip of the asymmetric pinion module 2-1 is connected with the slot wedge 4 through the dovetail groove, and the other side of the slot wedge 4 is also connected with the symmetric pinion module 2-2 through the dovetail groove. Then, the symmetric pinion module 2-2 and the slot wedge 4 are alternately connected, and finally connected with the other asymmetric pinion module 2-1. The slot wedge 4 is inserted into the asymmetric pinion module 2-1 or the symmetric pinion module 2-2 to make it completely fit with the asymmetric pinion module 2-1 or the symmetric pinion module 2-2. The slot wedge 4, the asymmetric pinion module 2-1 and the symmetric pinion module 2-2 are combined to form a rotor pinion-slot wedge integral module, and the shaped winding is wound on the integral module.

[0029] Further explanation, as shown in Figure 11As shown, the rotor large tooth module 3 is connected with the large dovetail groove of the rotor yoke 5 to form a plurality of uniformly distributed slot structures, and the inner layer split concentrated winding 6 is embedded in the slots.

[0030] Further, as shown in the figure, Figure 12 The outer diameter of each coil of the inner layer split concentrated winding 6 is increased once to prevent the coils from crossing during winding.

[0031] Further, as shown in the figure, Figure 13 When the inner layer split concentrated winding 6 is embedded in the rotor yoke 5, a whole winding can be arranged inside and outside, or upper and lower windings can be arranged.

[0032] Those skilled in the art will easily understand that the above description is only a preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A modular magnetic field-enhanced rotor structure for an AC excitation motor, characterized in that, include: Asymmetric small tooth module (2-1), symmetric small tooth module (2-2), rotor large tooth module (3), slot wedge (4), rotor yoke (5), inner layer split concentrated winding (6) and outer layer magnetic field strengthening winding (7); The rotor yoke (5) is provided with multiple rotor large tooth modules (3) along the circumferential direction, and multiple sets of inner layer split concentrated windings (6) are provided between adjacent large tooth modules (3). The toothless side of the asymmetrical small tooth module (2-1) is connected to the slot wedge (4), and the other side of the slot wedge (4) is connected to the symmetrical small tooth module (2-2); after multiple symmetrical small tooth modules (2-2) are alternately connected to multiple slot wedges (4), they are connected to another asymmetrical small tooth module (2-1) to form a small tooth-slot wedge combination module; Multiple small tooth-slot wedge combination modules are arranged around the outside of the rotor yoke (5), and the outer magnetic field strengthening winding (7) is arranged between adjacent small tooth-slot wedge combination modules.

2. The modular magnetic field strengthening rotor structure for an AC excitation motor according to claim 1, characterized in that, The rotor large tooth module (3) and the rotor yoke (5), the asymmetric small tooth module (2-1) and the slot wedge (4), the slot wedge (4) and the symmetric small tooth module (2-2), and the small tooth-slot wedge combination module and the rotor yoke (5) are all connected by dovetail grooves.

3. The modular magnetic field strengthening rotor structure for an AC excitation motor according to claim 2, characterized in that, The rotor large tooth module (3) has a rectangular symmetrical structure, and its inner diameter is provided with a dovetail structure for fixing the rotor large tooth module (3) to the rotor yoke (5); the outer diameter of the rotor large tooth module (3) is provided with a dovetail groove for connecting with the asymmetrical small tooth module (2-1).

4. The modular magnetic field strengthening rotor structure for an AC excitation motor according to claim 3, characterized in that, One side of the asymmetric small tooth module (2-1) is a toothless structure, and a dovetail structure for connecting the slot wedge (4) is provided on the toothless structure side; the other side of the asymmetric small tooth module (2-1) is a toothed structure; the radial direction of the asymmetric small tooth module (2-1) is a trapezoidal structure that is wider at the top and narrower at the bottom, and a dovetail structure for connecting with the outer diameter of the rotor large tooth module (3) is provided at its inner diameter.

5. The modular magnetic field strengthening rotor structure for an AC excitation motor according to claim 4, characterized in that, The radial direction of the symmetrical small tooth module (2-2) is a trapezoidal structure that is wider at the top and narrower at the bottom, and both sides are provided with dovetail structures for connecting with the slot wedge (4).

6. The modular magnetic field strengthening rotor structure for an AC excitation motor according to claim 5, characterized in that, The rotor yoke (5) is provided with multiple sets of rotor tooth structures along the circumference, and the top of the rotor tooth structure is provided with a dovetail groove; a dovetail groove for placing the rotor large tooth module (3) is provided between adjacent rotor tooth structures.

7. The modular magnetic field strengthening rotor structure for an AC excitation motor according to claim 6, characterized in that, The rotor tooth structure is provided with a rectangular slot, and the inner layer split concentrated winding (6) is located in the rectangular slot.

8. The modular magnetic field strengthening rotor structure for an AC excitation motor according to claim 7, characterized in that, The rotor large tooth module (3) and the rotor yoke (5) are made of high magnetic permeability material; the slot wedge (4) is made of non-magnetic material, and the slot wedge (4) has dovetail grooves on both sides for connecting with the symmetrical small tooth module (2-2).

9. A modular magnetic field-enhanced rotor structure for an AC excitation motor according to claim 8, characterized in that, The outer magnetic field strengthening winding (7) is a shaped coil with a fractional slot concentrated winding structure, and the magnetic field direction of the outer magnetic field strengthening winding (7) is the same as that of the inner split concentrated winding (6).

10. A modular magnetic field-enhanced rotor structure for an AC excitation motor according to claim 9, characterized in that, The positive and negative sides of the same phase winding of the inner layer split-type concentrated winding (6) are set at the bottom or top of the rectangular slot or on both sides of the rotor large tooth module (3).

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