CN204361870U - An ironless double air gap axial flux permanent magnet wind generator - Google Patents

Abstract

The utility model discloses a no iron core double air gap axial magnetic flow permanent magnet wind power generator, including main shaft, rotor and stator, the rotor contains two symmetric distribution in the rotor dish of stator both sides, and the inboard side of rotor dish all is equipped with the permanent magnet towards the stator, and the permanent magnet shape is for the cake shape or the runway shape of cutting of the take cambered surface that contains the magnetic pole contained angle of variation in size, and follows the adjacent permanent magnet of circumferencial direction and follow the relative permanent magnet polar arc coefficient difference of main shaft direction. The stator comprises stator coil windings and supporting pieces thereof, the stator adopts a single-layer centralized winding which is not overlapped and three-phase symmetrical, and the shape of the coil is rhombic or conical and has no iron core structure. The utility model discloses the radial magnetic flux of fungible tradition and the generator that has the iron core structure compare simple structure, start lightly, and generating efficiency and high quality, small in noise are applicable to very much small-size direct-driven formula vertical axis wind power generation system, but wide application requires power generation equipment to remove the flexibility good in cities, pastoral area, island, fishing boat etc. and the higher occasion of generating quality and efficiency.

Description

An ironless double air gap axial flux permanent magnet wind generator

technical field

The utility model relates to a wind power generator, in particular to a stator coreless double air gap axial flux permanent magnet induction wind power generator.

Background technique

At present, small wind turbines mainly have two forms of radial and axial flux. The axial flux generator has a compact structure, high torque density, and short axial length, so it is easy to design as a multi-pole motor; in addition, the stator is designed as The ironless structure can eliminate the influence of cogging torque force during generator operation, reduce hysteresis and eddy current loss, reduce the cut-in wind speed of the generator, and can run in a large wind speed range. Drive the wind power generation system, improve the reliability of the wind power generation system.

Small wind turbines require the motor to have low cut-in wind speed and large moment of inertia to generate electricity in the breeze; high power generation efficiency and low loss; high power generation quality and low harmonic content; light weight, small size, high material utilization, and compact and simple structure.

At present, this kind of coreless axial flux permanent magnet generator with high power quality output is very rare in China, such as the axial flux motor involved in the Chinese utility model patent CN 103887909A, the stator winding has an iron core, and its structure and Relevant theoretical studies at home and abroad are consistent. Due to its large starting torque, it is difficult to start power generation in light winds. At the same time, it is difficult to guarantee power quality, so it is not suitable for small wind power generation.

Contents of the invention

The purpose of the utility model is to provide a double-air-gap axial flux permanent magnet wind-driven generator capable of starting and generating electricity with light wind, high-quality electricity generation, light and stable operation, and simple and compact structure.

The technical solution adopted by the utility model is: the iron-less double air gap axial flux permanent magnet wind generator includes a main shaft, a rotor and a stator, the stator is fixedly connected to the main shaft, and the rotor contains two symmetrically distributed On the rotor discs on both sides of the stator, permanent magnets are provided on the inner side of the rotor discs facing the stator, and the rotor discs are supported on the main shaft. And the surface is arc-shaped and protruding, pie-shaped or runway-shaped.

The following are relevant technical means in some preferred schemes:

The permanent magnets are arranged with a plurality of permanent magnets along the circumferential direction of the rotor disk, N poles and S poles are evenly and alternately placed, and the adjacent permanent magnets along the circumferential direction and the permanent magnets opposite along the main axis have different pole arc coefficients, and the poles The arc coefficients are 0.7 and 0.8 respectively.

Further, the main surface of the permanent magnet is flat and installed on the surface of the rotor disk, and the other surface opposite to it is convex in an arc, and the convex surfaces of the arc are arranged opposite to each other in the axial direction.

Further, the total number of permanent magnets is an even number greater than 40, all of which are magnetized along the axial direction.

The stator includes a stator coil winding and a support member fixed together, the stator winding coil is fixedly connected to the main shaft through the support member, and the stator winding coil is processed by epoxy resin injection molding.

The stator winding adopts non-overlapping three-phase symmetrical single-layer concentrated winding, the shape is rhombus or cone, and there is no iron core and tooth slot structure.

Further, the coil electrical angle of the stator coil winding can range from 220° to 260°, and the total number of coils is a positive integer divisible by 3.

The main shaft is a hollow main shaft. The hollow main shaft is provided with small holes for the lead-out wires of the stator coil windings.

Compared with the existing axial flux generator, the utility model patent has the following advantages:

1. The axial flux permanent magnet generator shown in the utility model adopts the shape of a pie-shaped or runway-shaped permanent magnet with circular arc protrusions, and has the characteristics of high quality generator output power, low harmonic content, and sinusoidal waveform Good, the advantages of high utilization rate of permanent magnet materials, and the use of rhombic or conical coils that match the shape of permanent magnets can effectively reduce the length of the coil end and copper loss, and improve the power generation efficiency;

2. The arrangement of permanent magnets adopted by the utility model has the characteristics of reducing flux leakage, saving permanent magnet materials, and reducing torque fluctuations;

3. The utility model adopts a non-overlapping three-phase symmetrical single-layer centralized winding, which is diamond-shaped or conical in shape, and has a stator component structure without iron core and cogging. The stator has almost no hysteresis and eddy current loss, and at the same time avoids wind When starting the generator, it is necessary to overcome the influence of the cogging torque force. The non-cogging structure makes the coil winding more free and flexible, eliminating the constraints of the cogging shape, and the motor runs lighter and faster, and can achieve the goal of low-speed or even ultra-low-speed start-up power generation , improve the utilization rate of wind energy;

4. The utility model connects a plurality of coils in a certain order to form a stator winding, which is processed by epoxy resin injection molding, and the stator winding and the supporting parts are integrated to fix it on the main shaft to ensure the continuous stability of the motor There will be no vibration and loud noise during operation.

Based on the above advantages, the axial flux permanent magnet motor of the utility model can replace the traditional radial flux and generators with iron core structure. Compared with the generator with simple structure, it is easy to start, the power generation efficiency and quality are high, and the noise is small. It is very suitable for small direct-drive vertical-axis wind power generation systems, and can be widely used in cities, pastoral areas, islands, fishing boats and other occasions that require good mobile flexibility of power generation equipment, high power generation quality and high efficiency.

Description of drawings

Fig. 1 is the structural representation of the utility model;

Fig. 2 is a schematic diagram of a pie-cut permanent magnet;

Fig. 3 is a sectional view along A-A of Fig. 2;

Fig. 4 is a schematic diagram of the arrangement of the permanent magnets of the rotor disk;

Fig. 5 is a schematic diagram of the shape of the stator coil winding;

Fig. 6 is a schematic diagram of stator coil winding layout.

Each label in the figure: 1. Hollow main shaft, 2. Bearing end cover, 3. Upper rotor disk, 4. Bolt, 5. Bearing, 6. Stator coil winding support, 7. Permanent magnet, 8. Stator coil winding, 9 , casing, 10, lower rotor disk, 11, threading hole, 12, winding lead-out wire.

Detailed ways

The specific embodiment of the utility model will be further described below in conjunction with accompanying drawing:

As shown in Figure 1, the stator coreless axial flux permanent magnet generator includes a main shaft, a rotor and a stator. The stator is fixed on the main shaft, and the rotor includes two rotor disks. The rotor disks are placed on both sides of the stator and are movably connected with the main shaft.

The main shaft adopts a hollow main shaft 1 .

The rotor includes two upper and lower rotor disks 3 and 10, and permanent magnets 7 on the upper and lower rotor disks 3 and 10. The rotor rotates around the hollow main shaft 1 supported by it. The hollow main shaft 1 is a supporting member and does not rotate relative to the rotor. The upper and lower rotor disks 3, 10 are fixed on the generator casing 9 by six bolts 4, that is, the rotor disks 3, 10, the permanent magnet 7 and the casing form a rotating part.

The upper and lower rotor disks 3 and 10 are respectively provided with two kinds of permanent magnets 7 with different magnetic pole angles, and they all face the stator axially along the hollow main shaft 1, and there is a certain distance between the permanent magnets and the winding coils of the stator. Air gap distance, the N pole and S pole of the permanent magnet 7 are alternately placed along the circumferential direction inside the rotor disk (as shown in Figure 4), and the surfaces of the two permanent magnets on the rotor disk 3 and 10 that are opposite along the main axis The polarities are opposite, that is, the magnetization directions of the two are opposite along the main axis, one is facing upward and the other is downward, and the polar arc coefficients of the two are also different, and the distribution along the main axis is similar, that is, along the In the circumferential direction, the magnetization directions of two adjacent permanent magnets are opposite, and the polar arc coefficients are different.

The number of magnetic pole pairs of the rotor disk is a positive integer greater than 10, that is to say, the number of permanent magnets on each rotor disk is 20 or more, and the number of permanent magnets on one rotor disk = number of magnetic pole pairs × 2, the power generation The pole arc coefficient of the machine is any number between 0.7-0.8, then the permanent magnet magnetic pole angle = pole arc coefficient × number of magnetic pole pairs / 180, especially the poles of the two adjacent and opposite permanent magnets on the upper and lower rotor disks 3 and 10 The arc coefficients are different, that is, the included angles of the magnetic poles are different, that is, the included angles of the magnetic poles are one large and the other small. The two groups of pole arc coefficients of the utility model are respectively 0.7 and 0.8.

As shown in Figures 2 and 3, the shape of the permanent magnet 7 is a pie-cut shape, and the pie-cut shape permanent magnet is similar to cutting a circular permanent magnet into a shape with a certain magnetic pole angle; Shaped permanent magnet is to transform the linear part of the permanent magnet into a shape with a magnetic pole angle. The purpose of the preferred shape of the permanent magnet 7 is to make full use of the permanent magnet material and achieve the purpose of improving the utilization rate of the permanent magnet. In particular, the main surface of the permanent magnet 7 is flat and installed on the surface of the rotor disk. The other side opposite to it, that is, the side facing the coil, is designed as an arc convex, and the arc convex surface is arranged opposite to the axial direction. The main axis of the circular arc coincides with the 7 main axes of the permanent magnet. The purpose of the optimal circular arc convex structure is to improve the distribution characteristics of the sinusoidal magnetic field in the air gap of the generator, so that the air gap magnetic field is close to sinusoidal, which is ultimately conducive to reducing the harmonic output of the generator and improving Power output quality.

The permanent magnet 7 is made of NdFeB material with high magnetic energy product.

The stator has an iron-free and cogging structure as a whole. The iron-free motor has almost no hysteresis and eddy current loss, which avoids the need to overcome the influence of cogging torque when the wind turbine is started. The non-cogging structure makes the coil winding More freedom and flexibility, eliminating the constraints of the alveolar shape.

The stator includes a stator coil winding 8 and a stator support member 6. The stator coil winding 8 and the support member 6 are fixed together through epoxy resin injection molding of the winding coil, and installed on the hollow main shaft 1, wherein the coil winding 8 is drawn out The wire 12 is led out through the small hole 11 on the hollow main shaft 1, and the stator is stationary relative to the rotor. In summary, the stator coil winding 8, the support 6 and the hollow shaft 1 form the stationary part.

As shown in Figures 5 and 6, the shape of the stator coil winding 8 is a rhombus or a cone, and there is no iron core structure. The conductor of the corresponding coil part is effective, and it can also effectively cut the magnetic force line and induce electric energy, which reduces the length of the coil end, relatively reduces copper consumption, and improves power generation efficiency.

The stator coil winding 8 adopts non-overlapping three-phase symmetrical concentrated winding. The number of coils is determined by the number of pole pairs of the motor and the included angle of the coils, that is to say, the number of coils=360×the number of magnetic pole pairs/the included angle of the coils. The angle is the electrical angle, not the mechanical angle, the electrical angle = the number of magnetic pole pairs × 360, when θp/θc>0.4 (as shown in Figure 5, here the electrical angle θc is used to represent the width of the coil at a certain radius), and the included angle of the coil is 220 -260°, the coil angle involved in the utility model is selected according to the largest group of polar arc coefficients, namely 0.7 and 0.8, and the coil angle is 240° electrical angle.

The support member 6 of the stator coil winding 8 extends radially outward from the hollow main shaft 1 to the inside of the winding 8, and the support member 6 is arranged between the two rotor disks 3 and 10, that is, on the arc surface of the upper and lower permanent magnets 7. In the middle, the stator support 6 is nested on the hollow main shaft 1 through interference fit, and remains stationary relative to the rotor. The shortest distance between the arc surface of the permanent magnet and the surface of the stator coil is 0.5-2.0 mm.

The main bearing part 5 is arranged on the outer surface of the hollow main shaft 1, and the upper and lower bearings 5 are respectively embedded in the inner holes of the two rotor discs 3 and 10 along the main shaft direction, and the distance between the rotor discs 3 and 10 is equal, and the upper and lower bearings 5 can make the rotor rotate around the hollow main shaft 1, and at the same time support the weight of the rotor and the load applied to the rotor. The upper and lower bearings 5 are respectively provided with main bearing end covers 2 for sealing function along the outer ends of the main shaft.

As mentioned above, the utility model has a simple and compact structure, and the motor starts lightly. It is very suitable for the breeze wind power generation system. It has the advantages of low starting speed, high power generation efficiency and quality, stable operation and low loss.

It should be pointed out that it should be clear to those skilled in the art that, without departing from the scope of protection requested by the claims of the present invention and without violating the gist of the present invention, equivalents can be made to the specific embodiments Alternatives or obvious variations, and several improvements or modifications.

Claims (9)

1. the two air-gap shaft of iron-core-free is to flux permanent magnet wind generator, comprise main shaft, rotor and stator, described stator is fixedly connected with described main shaft, described rotor is symmetrically distributed in upper rotor part dish (3) and the lower rotor part dish (10) of described stator both sides containing two, rotor disk (3,10) medial surface is equipped with permanent magnet (7) to described stator, rotor disk is bearing on described main shaft, and be fixedly connected with electric generator casing (9), it is characterized in that: permanent magnet (7) shape is cut cheese or track type containing vary in size pole embrace and surperficial circular arc projection.

2. the two air-gap shaft of iron-core-free according to claim 1 is to flux permanent magnet wind generator, it is characterized in that: permanent magnet (7) is the multiple permanent magnets along rotor disk (3,10) circumferential directions, evenly alternately place N pole and S pole, and adjacent permanent magnet is along the circumferential direction different with the permanent magnet pole embrace relative along described major axes orientation, pole embrace gets 0.7 and 0.8 respectively.

3. the two air-gap shaft of iron-core-free according to claim 2 is to flux permanent magnet wind generator, it is characterized in that: permanent magnet (7) first type surface is plane, be arranged on rotor disk (3,10) face, another side on the other side is that circular arc is protruding, and circular arc crowning is positioned opposite along major axes orientation.

4. the two air-gap shaft of iron-core-free according to claim 3 is to flux permanent magnet wind generator, it is characterized in that: permanent magnet (7) total number be greater than 40 even number, magnetizing direction is axis.

5. according to the two air-gap shaft of the arbitrary described iron-core-free of claim 1-4 to flux permanent magnet wind generator, it is characterized in that: the strutting piece (6) that described stator comprises stator coil winding (8) and is fixed together, stator coil winding (8) is fixedly connected with described main shaft by strutting piece (6).

6. the two air-gap shaft of iron-core-free according to claim 5 is to flux permanent magnet wind generator, it is characterized in that: stator coil winding (8) adopts the centralized winding of individual layer of not overlapping three-phase symmetrical, and shape is rhombus or taper, iron-core-free and tooth slot structure.

7. the two air-gap shaft of iron-core-free according to claim 6 is to flux permanent magnet wind generator, and it is characterized in that: the coil electric angle of stator coil winding (8), span is 220-260 °.

8. the two air-gap shaft of iron-core-free according to claim 7 is to flux permanent magnet wind generator, and it is characterized in that: stator coil winding (8) coil electric angle, get 240 °, coil number adds up to the positive integer that can be divided exactly by 3 .

9. the two air-gap shaft of iron-core-free according to claim 8 is to flux permanent magnet wind generator, and it is characterized in that: described main shaft is hollow spindle (1), hollow spindle (1) is provided with the through wires hole (11) of stator coil winding (8) lead-out wire (12).