Modular field strengthening rotor structure for an ac excited electric machine

Abstract

The application discloses an alternating-current excited motor modularized magnetic field reinforced rotor structure and belongs to the technical field of alternating-current excited motor generators, comprising asymmetric small-tooth modules, symmetric small-tooth modules, rotor large-tooth modules, slot wedges, a rotor yoke, inner-layer split concentrated windings and outer-layer magnetic field reinforced windings; the rotor yoke is provided with the rotor large-tooth modules in the circumferential direction, and the inner-layer split concentrated windings are arranged between adjacent large-tooth modules; the tooth tip-free side of the asymmetric small-tooth module is connected with the slot wedge, the symmetric small-tooth module is alternately connected with the slot wedge and then connected with another asymmetric small-tooth module to form a small-tooth-slot wedge combined module; the small-tooth-slot wedge combined module is arranged outside the rotor yoke, and the outer-layer magnetic field reinforced windings are arranged between adjacent small-tooth-slot wedge combined modules. The motor slot current density is lower through the rotor modification, the pole-slot matching is more flexible in selection, the low-slot current and high-air-gap magnetic flux density design of the motor are realized, and the operation reliability of the large motor is improved.

Description

TECHNICAL FIELD

[0001] The 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 modularized magnetic field reinforced rotor structure of an 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 the current power system, 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 the new power system. Compared with the fixed-speed pumped storage technology using synchronous motors, the variable-speed pumped storage using alternating current excitation motors (or double-fed asynchronous motors) as generators-motors has significant advantages in terms of hydraulic performance, power regulation characteristics and system comprehensive efficiency. By controlling the frequency of the rotor current, the mechanical speed of the rotor can be changed to achieve variable-speed operation.

[0003] The conventional alternating current excitation motor rotor winding adopts a distributed structure, i.e., the winding end is too long and difficult to fix, and the reliability of the rotor is significantly reduced. 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 application provides an alternating current excitation motor modularized magnetic field reinforced rotor structure, thereby solving the technical problem of excessive slot current density.

[0005] To achieve the above-mentioned purpose, according to one aspect of the application, an alternating current excitation motor modularized magnetic field reinforced rotor structure 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 reinforced winding.

[0006] 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.

[0007] The toothless 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.

[0008] A plurality of small tooth-slot wedge combination modules are arranged outside the rotor yoke, and the outer layer magnetic field strengthening winding is arranged between adjacent small tooth-slot wedge combination modules.

[0009] Preferably, the rotor large tooth module, the rotor yoke, the asymmetric small tooth module and 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.

[0010] Preferably, the rotor large tooth module is a rectangular symmetric structure, the inner diameter of which is provided with a dovetail structure for fixing the rotor large tooth module to the rotor yoke, and the outer diameter of the rotor large tooth module is provided with a dovetail slot for connecting the asymmetric small tooth module.

[0011] Preferably, one side of the asymmetric small tooth module is a tooth tip-free structure, and the other side of the asymmetric small tooth module is a tooth tip structure, and the radial direction of the asymmetric small tooth module is a trapezoidal structure with the upper part being wide and the lower part being narrow, and the inner diameter of the asymmetric small tooth module is provided with a dovetail structure for connecting the outer diameter of the rotor large tooth module.

[0012] Preferably, the radial direction of the symmetric small tooth module is a trapezoidal structure with the upper part being wide and the lower part being narrow, and both sides of the symmetric small tooth module are provided with dovetail structures for connecting the slot wedge.

[0013] Preferably, the rotor yoke is provided with a plurality of rotor tooth structures along the circumferential direction, and the top of the rotor tooth structure is provided with a dovetail slot, and the dovetail slot is arranged between adjacent rotor tooth structures for placing the rotor large tooth module.

[0014] Preferably, the rotor tooth structure is provided with a rectangular slot, and the inner layer split concentrated winding is located in the rectangular slot.

[0015] Preferably, the rotor large tooth module and the rotor yoke are made of high magnetic permeability material, the slot wedge is made of non-magnetic material, and the slot wedge is provided with dovetail slots on both sides for connecting the symmetric small tooth module.

[0016] 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.

[0017] 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 large tooth module.

[0018] In general, compared with the prior art, the above technical solutions conceived by the present application can achieve the following beneficial effects:

[0019] 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.

[0020] 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

[0021] Figure 1 is the cross-sectional view of the alternating current excited motor of the magnetic field reinforced rotor structure of the present application;

[0022] 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;

[0023] 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;

[0024] Figure 4 is the partial schematic diagram of the rotor structure of the present application;

[0025] Figure 5 is the schematic diagram of the asymmetric small tooth module of the present application;

[0026] Figure 6 is the schematic diagram of the symmetric small tooth module of the present application;

[0027] Figure 7 is the schematic diagram of the rotor large tooth module of the present application;

[0028] Figure 8 is the schematic diagram of the slot wedge of the present application;

[0029] Figure 9 is the schematic diagram of the rotor yoke part of the present application;

[0030] Figure 10 is the schematic diagram of the rotor asymmetric small tooth, symmetric small tooth module and slot wedge combined module of the present application;

[0031] Figure 11 is the schematic diagram of the rotor module embedded with distributed winding of the present application;

[0032] Figure 12is a three-dimensional distribution diagram of an inner layer split winding of the application;

[0033] Figure 13 is an assembly diagram of the upper and lower arranged inner layer split winding embedded in a rotor yoke of the application.

[0034] In all the drawings, the same reference signs are used to represent the same elements or structures, wherein: 1, stator; 2-1, asymmetric tooth module; 2-2, symmetric tooth module; 3, rotor tooth module; 4, slot wedge; 5, rotor yoke; 6, inner layer split concentrated winding; 7, outer layer magnetic field strengthening winding. DETAILED DESCRIPTION

[0035] 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 examples. It should be understood that the specific examples described herein are merely used to explain the present application and are not 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.

[0036] As shown in Figure 1 The present application proposes a modular magnetic field strengthening rotor structure of an alternating current excited motor, which comprises asymmetric tooth modules 2-1, symmetric tooth modules 2-2, rotor tooth modules 3, slot wedges 4, a rotor yoke 5, an inner layer split concentrated winding 6 and an outer layer magnetic field strengthening winding 7. First, the tooth tip-free side of the asymmetric tooth module 2-1 is connected with the slot wedge 4, and the other side of the slot wedge 4 is connected with the symmetric tooth module 2-2. Next, the symmetric tooth module 2-2 and the slot wedge 4 are alternately connected, and finally connected with another asymmetric tooth module 2-1, forming a tooth-slot wedge combination module. The outer layer magnetic field strengthening winding 7 is wound on the tooth-slot wedge combination module. The rotor tooth 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 tooth module 3 and the rotor yoke 5. Finally, the tooth-slot wedge combination module with the wound winding is connected with the rotor tooth module 3 and the rotor yoke 5 to form the modular magnetic field strengthening rotor structure of the alternating current excited motor. The inner layer split concentrated winding 6 and the outer layer magnetic field strengthening winding 7 belong to runway type formed windings, which are sleeved on each corresponding tooth-slot wedge combination rotor module, and the inner layer split winding and the magnetic field strengthening winding do not overlap.

[0037] Further explanation is given as shown in Figure 2 The outer layer magnetic 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 arrangement without overlapping parts. The formed coil of the inner layer split winding is arranged in an upper and lower arrangement on both sides of the same phase winding

[0038] Further, as shown in Figure 3 The split inner layer concentrated winding 6 can also be arranged at the bottom and top of the slot.

[0039] Further, as shown in Figure 4 The two kinds of pinion modules are connected with the slot wedge through dovetail grooves, and the pinion and the large tooth, the pinion and the yoke, and the large tooth and the yoke are connected through large dovetail grooves.

[0040] Further, as shown in Figure 5 The asymmetric pinion module 2-1 has a tooth tip structure on one side and no tooth tip structure on the other side, and the side connected with the slot wedge 4 adopts the no tooth tip structure, and the other side adopts the tooth tip structure. The side without tooth tip of the asymmetric pinion module 2-1 adopts a small dovetail structure cut by a wire, and the asymmetric pinion module 2-1 adopts a trapezoidal structure with a wide upper part and a narrow lower part in the radial direction, and a larger dovetail structure is arranged at the inner diameter for fixing with the rotor large tooth module 3.

[0041] Further, as shown in Figure 6 The symmetric pinion module 2-2 adopts a trapezoidal structure with a wide upper part and a narrow lower part, and has small dovetail structures on both sides for connecting with the slot wedge 4.

[0042] Further, as shown in Figure 7 The rotor large 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, and the processed silicon steel sheet is stacked and welded to form the rotor large tooth module 3.

[0043] Further, as shown in Figure 8 The slot wedge 4 is made of non-magnetic material, and has a trapezoidal structure with a narrow upper part and a wide lower part, and shallow dovetail structure grooves are opened on both sides of the slot wedge 4 to cooperate with the dovetail structure on the side without tooth tip of the asymmetric pinion module 2-1.

[0044] Further, as shown in Figure 9 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 opened to have a dovetail groove structure.

[0045] Further, as shown in Figure 10As shown, the non-symmetrical small tooth module 2-1 is connected with the slot wedge 4 through the dovetail groove on one side without tooth tip, and the other side of the slot wedge 4 is also connected with the symmetrical small tooth module 2-2 through the dovetail groove, then the symmetrical small tooth module 2-2 is alternately connected with the slot wedge 4, and finally connected with another non-symmetrical small tooth module 2-1, the slot wedge 4 is inserted into the non-symmetrical small tooth module 2-1 or the symmetrical small tooth module 2-2 to make it completely fit with the non-symmetrical small tooth module 2-1 or the symmetrical small tooth module 2-2, the slot wedge 4, the non-symmetrical small tooth module 2-1 and the symmetrical small tooth module 2-2 are combined to form a rotor small tooth-slot wedge integral module, and the shaped winding is wound on the integral module.

[0046] Further, as shown in FIG. 4, the rotor tooth module 2 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 into the slot. Figure 11

[0047] Further, as shown in FIG. 4, the rotor tooth module 2 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 into the slot. Figure 12

[0048] Further, as shown in FIG. 4, the rotor tooth module 2 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 into the slot. Figure 13

[0049] Those skilled in the art will readily understand that the above description is only the preferred embodiment of the present application, and is not intended to limit the present application, and 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. An alternating current excited electric machine modular magnetic field strengthening rotor structure, characterized by, The application relates to a rotor module for a permanent magnet motor. The rotor module comprises an asymmetric tooth module (2-1), a symmetric tooth module (2-2), a rotor tooth module (3), a slot wedge (4), a rotor yoke (5), an inner layer split concentrated winding (6) and an outer layer magnetic field strengthening winding (7). The rotor yoke (5) is provided with a plurality of rotor tooth modules (3) in the circumferential direction, and a plurality of groups of inner layer split concentrated windings (6) are arranged between adjacent rotor tooth modules (3). One side of the asymmetric tooth module (2-1) is connected with the slot wedge (4), and the other side of the slot wedge (4) is connected with the symmetric tooth module (2-2); a plurality of symmetric tooth modules (2-2) and a plurality of slot wedges (4) are alternately connected and then connected with another asymmetric tooth module (2-1), thereby forming a tooth-slot wedge combined module. A plurality of tooth-slot wedge combined modules are arranged outside the rotor yoke (5), and the outer layer magnetic field strengthening winding (7) is arranged between adjacent tooth-slot wedge combined modules.

2. An alternating current excited electric machine modular magnetic field strengthening rotor structure according to claim 1, characterized in that, The rotor tooth module (3), the rotor yoke (5), the asymmetric tooth module (2-1), the slot wedge (4), the slot wedge (4) and the symmetric tooth module (2-2) and the tooth-slot wedge combined module and the rotor yoke (5) are all connected through dovetail grooves.

3. An alternating current excited electric machine modular magnetic field strengthening rotor structure according to claim 2, characterized in that, The rotor tooth module (3) has a rectangular symmetric structure, the inner diameter of the rotor tooth module (3) is provided with a dovetail structure for fixing the rotor tooth module (3) to the rotor yoke (5), and the outer diameter of the rotor tooth module (3) is provided with a dovetail groove for connecting the asymmetric tooth module (2-1).

4. An alternating current excited electric machine modular magnetic field strengthening rotor structure according to claim 3, characterized in that, One side of the asymmetric tooth module (2-1) is a tooth tip-free structure, the tooth tip-free structure is provided with a dovetail structure for connecting the slot wedge (4), the other side of the asymmetric tooth module (2-1) is a tooth tip structure, and the radial direction of the asymmetric tooth module (2-1) is a trapezoidal structure which is wide at the top and narrow at the bottom, and the inner diameter of the asymmetric tooth module (2-1) is provided with a dovetail structure for connecting the outer diameter of the rotor tooth module (3).

5. An alternating current excited electric machine modular magnetic field strengthening rotor structure according to claim 4, characterized in that, The radial direction of the symmetric tooth module (2-2) is a trapezoidal structure which is wide at the top and narrow at the bottom, and both sides of the symmetric tooth module (2-2) are provided with dovetail structures for connecting the slot wedge (4).

6. An alternating current excited electric motor modular magnetic field intensifier rotor structure according to claim 5 wherein, The rotor yoke (5) is provided with a plurality of groups of rotor tooth structures in the circumferential direction, the top of the rotor tooth structure is provided with a dovetail groove, and a dovetail groove for placing the rotor tooth module (3) is arranged between adjacent rotor tooth structures.

7. An alternating current excited electric motor modular magnetic field intensifier rotor structure according to claim 6 wherein, The rotor tooth structure is provided with a rectangular groove, and the inner layer split concentrated winding (6) is arranged in the rectangular groove.

8. An alternating current excited electric motor modular magnetic field intensifier rotor structure according to claim 7, characterized by, The rotor 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 both sides of the slot wedge (4) are provided with dovetail grooves for connecting the symmetric tooth module (2-2).

9. An alternating current excited electric motor modular magnetic field intensifier rotor structure according to claim 8, characterized by, The outer layer magnetic field strengthening winding (7) is a fractional slot concentrated winding structure formed coil, and the magnetic field direction of the outer layer magnetic field strengthening winding (7) is the same as that of the inner layer split concentrated winding (6).

10. An alternating current excited electric motor modular magnetic field intensifier rotor structure according to claim 9, characterized by, The positive and negative edges of the same phase winding of the inner layer split concentrated winding (6) are arranged at the bottom of the rectangular groove, the top of the rectangular groove or both sides of the rotor tooth module (3).

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