WO2023109885A1

WO2023109885A1 - Stator assembly and flat wire electric motor having multiple wires arranged in same slot layer

Info

Publication number: WO2023109885A1
Application number: PCT/CN2022/139200
Authority: WO
Inventors: 卢芳友
Original assignee: 上海易唯科电机技术有限公司
Priority date: 2021-12-17
Filing date: 2022-12-15
Publication date: 2023-06-22

Abstract

The present application relates to the technical field of flat wire electric motors, and particularly to a stator assembly and flat wire electric motor having multiple wires arranged in the same slot layer. The stator assembly comprises a stator core and a stator winding, wherein the stator core is substantially cylindrical; a plurality of stator slots are provided in the stator core; and a plurality of combined conductor layer groups are arranged in each stator slot. Compared with the prior art, the stator assembly provided in the present application can allow the length-width ratio of each rectangular conductor to be reduced, while ensuring that the total sectional areas of conductors in the stator slots are similar, so that U-shaped wire forming is facilitated, and the manufacturability of same is better. In addition, the length and width of each rectangular conductor in the stator slots and the shape of the stator slot are adjusted, and the radial distance of the stator slot, the inner diameter of a stator, and a stator yoke portion are adjusted by means of a stator toothing, so that the flux density distribution of each part of the stator assembly is reasonable, the slot filling rate is improved, and the working efficiency of the electric motor is improved.

Description

A stator assembly with multiple wires in the same slot layer and a flat wire motor

technical field

The application belongs to the technical field of flat wire motors, and in particular relates to a stator assembly with multiple wires in the same slot layer and a flat wire motor.

Background technique

Flat wire motor is a new type of winding method mainly researched by major motor manufacturers and developers. As the speed of flat wire motors is getting higher and higher, the number of layers in the stator slots of flat wire motors is increasing, and the aspect ratio of rectangular conductors is getting larger and larger, which makes it difficult to form conductors, turn heads, poor manufacturability, and slot utilization. Low, reducing the efficiency of the motor.

Moreover, in the existing flat wire motor scheme, the voltage drop between the enameled wires is relatively large in the high working voltage environment of the enameled flat wire motor, and the insulation and voltage resistance of the enameled wires is increasingly challenged.

Contents of the invention

In view of the above problems, the present application provides a stator assembly, the stator assembly includes a stator core and a stator winding; the stator core is generally cylindrical; several stator slots are arranged on the stator core, and the stator slots are arranged along The cores are arranged in sequence in the circumferential direction, forming a circular array; the winding of the stator winding adopts a rectangular conductor,

Each stator slot is provided with several layers of combined conductor layer groups, and each layer of combined conductor layer groups in the same stator slot is arranged in sequence along the radial direction of the stator core;

Each combined conductor layer group contains two or more than two rectangular conductors, and each group of rectangular conductors is sequentially arranged along the circumferential direction of the stator core.

Further, the aspect ratio of the rectangular conductors in the composite conductor layer group does not exceed 2.5.

Further, even-numbered composite conductor layers are arranged in the stator slot, or odd-numbered composite conductor layers are arranged in the stator slot.

Further, one or more independent conductor layer groups are arranged in each stator slot, and each independent conductor layer group contains only one rectangular conductor;

The combined conductor layer group and the independent conductor layer group in the same stator slot are arranged sequentially along the radial direction of the stator core; the independent conductor layer group is arranged close to the center of the stator core, and the combined conductor layer group is arranged near the outer wall of the stator core.

Further, the aspect ratio of the rectangular conductors in the independent conductor layer group does not exceed 3.

Further, the stator winding includes one or more independent branches; in the same independent branch, the rectangular conductors located in different conductor layer groups are connected in series.

Further, the combined conductor layer group includes an even number of rectangular conductors, and the independent conductor layers are even-numbered layers.

Further, the combined conductor layer set near the outer wall of the stator core includes two rectangular wires, and the stator assembly is provided with n pairs of poles, each pole includes six stator slots, where n is an even number greater than or equal to 4;

Each phase winding of the stator winding includes two branches, the first and the end of the two branches come out from the wire layer at the bottom of the slot, and the first ends of the two branches are located in the same pole; the winding of the two branches is in the stator iron The direction of extension on the core circumference is opposite.

Further, each branch is composed of several minimum balancing units connected in series, and the number of minimum balancing units connected in series in two branches in the same phase winding is the same.

Furthermore, a minimum equalization unit is composed of four stacked winding coil units connected in series, and its windings span three consecutive poles, and all the wires in the slots of a minimum equalization unit are merged according to the slot levels to meet the requirements of four complete stators. slot space.

Further, the minimum equalization unit includes a first minimum balance unit and a second minimum balance unit; the windings of the first minimum balance unit and the second minimum balance unit extend in opposite directions on the circumference of the stator core; There are two branches, and a minimum equalization unit is used in each branch.

Further, the head ends of the two branches in the same phase winding are located in the same stator slot.

Further, in the same phase winding, the two branch windings have four beginnings and ends, and the two beginnings or ends with the closest distance are set as lead-out lines, and the remaining two are set as star-point lines.

The present application also provides a flat-wire motor with multiple wires in the same slot layer, which includes a rotor assembly and the above-mentioned stator assembly, and the rotor assembly is located inside the stator assembly.

The beneficial effect of this application is:

1. The stator assembly proposed in this application reduces the aspect ratio of each rectangular conductor while ensuring that the total cross-sectional area of the conductors in the stator slot is similar, which is beneficial to the U-shaped line forming and has better manufacturability; at the same time, the stator is adjusted The length and width of each rectangular conductor in the slot, adjust the stator slot shape, adjust the radial distance of the stator slot by using the stator teeth, adjust the inner diameter of the stator, and adjust the stator yoke to make the magnetic density distribution of each part of the stator assembly reasonable and improve The slot full rate is improved, and the working efficiency of the motor is improved.

2. The stator assembly proposed by this application reduces the number of conductor layers in the stator slot along the radial direction of the stator core, reduces the requirements for the twisting tooling, and improves the production quality and efficiency.

3. Utilizing the layout of double wires at the bottom of the stator slot, the winding method of the winding is changed, so that the windings of the two branches in the same phase winding extend in opposite directions along the circumference of the stator core. In addition, the two branches in the same phase winding have the same number of minimum equalization units connected in series, so that the phase winding reaches a balanced circuit state.

4. Set the winding heads of the two branches in the same stator slot or in the same pole, and the winding head and end of a branch span enough stator slots to reduce the stator slot. The effect of the highest slot pressure drop between all conductors.

5. The three-phase winding star point line and the winding lead-out line are drawn from the bottom winding of the slot, which creates conditions for the internal connection and external connection lines of the motor winding to not occupy the axial space.

Additional features and advantages of the application will be set forth in the description which follows, and, in part, will be obvious from the description, or may be learned by practice of the application. The objectives and other advantages of the application may be realized and attained by the structure pointed out in the written description, claims hereof as well as the appended drawings.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings that need to be used in the descriptions of the embodiments or related technologies. Obviously, the drawings in the following description are the For some embodiments of the application, those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is the structural representation of flat wire motor in the related art;

Fig. 2 is an enlarged schematic diagram of part A in Fig. 1;

Fig. 3 is a partial sectional view of a stator slot of a stator core of a flat wire motor in the related art;

Fig. 4 is a schematic structural view of a flat wire motor in which only combined conductor layer groups are arranged in the stator slot of the embodiment of the present application;

5 is a schematic structural view of a flat wire motor with independent conductor layer groups disposed in the stator slot of the embodiment of the present application;

Figure 6 is an enlarged schematic view of part B in Figure 5;

Fig. 7 is a partial cross-sectional view of the stator core with only the combined conductor layer group set in the unequal-width stator slot of the embodiment of the present application;

Fig. 8 is a partial cross-sectional view of a stator core with an independent conductor layer group in a stator slot of unequal width according to an embodiment of the present application;

Fig. 9 is a partial cross-sectional view of a stator core with three independent conductor layer groups in the unequal-width stator slot of the embodiment of the present application

Fig. 10 is a partial cross-sectional view of a stator core with six independent conductor layer groups in a stator slot of unequal width according to an embodiment of the present application;

Fig. 11 is a partial cross-sectional view of stator cores with one, two and three conductor composite layers in stator slots of unequal width according to the embodiment of the present application;

Fig. 12 is a partial cross-sectional view of a stator core with two independent conductor layer groups in an equal-width stator slot in an embodiment of the present application;

Fig. 13 shows a cross-sectional view of a stator slot with two independent conductor layer groups in the unequal-width stator slot of the embodiment of the present application;

Fig. 14 is a schematic diagram of partial expansion of the stator winding of the embodiment of the present application;

Fig. 15 is an enlarged schematic diagram of part A in Fig. 14;

FIG. 16 is a schematic diagram of the wiring of a minimum equalization unit in the embodiment of the present application;

Fig. 17 is a schematic diagram of partial winding when the stator assembly has 8 poles and 48 slots and the number of branches is 2 in the embodiment of the present application.

In the figure: 1-stator core; 2-stator winding; 3-stator slot; 4-combined conductor layer group; 5-independent conductor layer group.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments It is a part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.

As shown in Figures 1 and 2, it is a commonly used winding method for flat wire motors in the related art, and the aspect ratio of the rectangular conductor used is too large. When the aspect ratio is greater than 3.5, when the end of the rectangular conductor is twisted and welded, the inner side of the twisted part is squeezed and easily wrinkled, and the outer side of the twisted part is stretched and easily broken. Therefore, existing flat wire motors have problems such as large bending radius of the stator winding, difficulty in forming the crown end, and poor manufacturability.

In addition, as shown in Figure 3, it is a partial cross-sectional view of some stator slots of the stator core of a flat-wire motor in the related art. Several layers of equal-sized rectangular conductors are arranged in sequence in each stator slot, and the utilization rate of the slots cannot be maximized. The ratio is 71.7% (pure copper).

In addition, the applicant found that the insulation withstand voltage capability of the enameled wire used in the flat wire motor is increasingly challenged. If the voltage drop between the wires in the same slot can be reduced, it will be very beneficial to improve the reliability of the motor winding; in addition, in the application of the motor, it is necessary to consider increasing the space utilization of the motor stator. In some special occasions, It is hoped that the lead wire of the motor does not occupy the axial space.

An embodiment of the present application provides a flat wire motor with multiple wires in the same slot layer, including a rotor assembly and a stator assembly, and the rotor assembly is located inside the stator assembly.

Specifically, as shown in Fig. 4, Fig. 5 and Fig. 6, the stator assembly includes a stator core 1 and a stator winding 2; Contains the motor rotor assembly. The stator core 1 is provided with a plurality of stator slots 3 , and the stator slots 3 are arranged in sequence along the circumferential direction of the stator core 1 in a ring-shaped array. The winding wires of the stator winding 2 adopt rectangular conductors, and the winding wires are evenly and symmetrically arranged in the stator slot 3 .

Specifically, the stator winding 2 includes a slot winding and an end winding. The slot winding refers to the rectangular conductor located in the stator slot; the end winding refers to the conductor located on both sides of the stator core 1, which is used to connect the slot windings in series to form a complete winding branch, which is divided into crown ends and solder ends.

Further, as shown in FIG. 7 , several combined conductor layer groups 4 are arranged in each of the stator slots 3 , and the combined conductor layer groups 4 in the same stator slot are arranged sequentially along the radial direction of the stator core.

Each combined conductor layer group 4 includes two or more rectangular conductors, and the rectangular conductors in the same combined conductor layer group 4 are sequentially arranged along the circumferential direction of the stator core 1 .

In the same stator slot, a plurality of rectangular conductors are arranged along the circumferential direction of the stator core. While ensuring that the total cross-sectional area of the conductors in the stator slot is similar, the aspect ratio of each rectangular conductor is reduced, which is beneficial to U-shaped Wire forming, better workmanship.

Exemplarily, as shown in FIG. 7, four composite conductor layer groups 4 are provided in each stator slot 4 along the radial direction of the stator core 1, and each composite conductor layer group 4 includes two rectangular conductors. .

The aspect ratio of the rectangular conductors in the composite conductor layer group 4 may not exceed 2.5. The aspect ratio of the rectangular conductor is reduced, which effectively reduces the difficulty of the end-twisting process of the rectangular conductor in the combined conductor layer group 4, which is beneficial to the U-shaped line forming; and can improve the slot fullness rate, so that the slot fullness rate reaches 71.9% ( pure copper).

By setting the combined conductor layer group, multiple rectangular conductors are arranged on the same layer of the same stator slot, and the aspect ratio of each rectangular conductor is reduced while ensuring that the total cross-sectional area of the conductors in the stator slot is similar, which is beneficial to U Shaped line forming, better workmanship; at the same time adjust the length and width of each rectangular conductor in the stator slot, adjust the stator slot shape, use the stator teeth, adjust the radial distance of the stator slot, adjust the inner diameter of the stator, adjust the stator yoke, The magnetic density distribution of each part of the stator assembly is made reasonable, the slot utilization rate is improved, and the working efficiency of the motor is improved.

Further, as shown in Figures 8-13, one or more independent conductor layer groups 5 can also be arranged in each of the stator slots 3; the combined conductor layer group 4 and the independent conductor layer in the same stator slot 3 Group 5, arranged in sequence along the stator core 1 radial direction; the independent conductor layer group 5 is set close to the center of the stator core 1 (stator slot notch), and the combined conductor layer group 4 is located close to the outer wall of the stator core 1 (stator Slot bottom) setting.

Specifically, each independent conductor layer group 5 includes only one rectangular conductor. The independent conductor layer group 5 is arranged near the center 1 of the stator core, which effectively reduces the loss caused by the rectangular conductor. The loss includes AC loss and DC loss; AC loss is the loss related to the current frequency caused by skin effect, proximity effect, eddy current, etc., and DC loss is the product of the DC resistance of the conductor and the square of the current, which has nothing to do with the frequency of the current .

The aspect ratio of the rectangular conductors in the independent conductor layer group 5 does not exceed 3. While ensuring that the rectangular conductor in the independent conductor layer group 5 produces less loss, it reduces the difficulty of the end twisting process of the rectangular conductor, which is beneficial to the U-shaped wire forming.

Further, the stator winding 2 includes one or more independent branches. In the same independent branch, the rectangular conductors located in different layer groups are all connected in series.

Exemplarily, as shown in FIG. 8 , in each stator slot 3 , five layers of conductor layer groups are arranged radially along the stator core 1 . Along the direction from the outer wall of the stator core to the center, they are successively named as the first layer, the second layer, the third layer, the fourth layer and the fifth layer conductor layer group.

Among them, the conductor layer groups of the first layer, the second layer, the third layer and the fourth layer are combined conductor layer groups 4, and each combined conductor layer group 4 is provided with two rectangular conductors, and the two rectangular conductors are arranged along the stator iron layer. The cores 1 are arranged in the circumferential direction, and the aspect ratio of each rectangular conductor is less than 2.5.

The fifth conductor layer group is the conductor layer group closest to the center of the stator core 1, which is an independent conductor layer group 5, and the fifth conductor layer group is composed of a rectangular conductor whose aspect ratio is less than 3 .

As shown in Figure 8-13, the combined arrangement of the combined conductor layer group 4 and the independent conductor layer group 5 is used to reduce the end twist of the rectangular conductor while ensuring that the rectangular conductor in the stator winding 2 produces less loss. Craft difficulty. Moreover, the stator assembly adopts the arrangement of mixed conductors, which further improves the slot fullness rate, making the slot fullness rate reach 72.6% (pure copper).

It should be noted that, in the actual design and production process, due to the influence of the structure and size of the motor, in order to ensure that the loss generated by the stator assembly is kept at a low level, except for the first layer of conductor layer group closest to the center of the stator core, the The multi-layer conductor layer group in the center of the core can also be set as an independent conductor layer group, as shown in Fig. 9 and Fig. 10 , which will not be described in detail here. In addition, in the actual design and production process, the aspect ratio of each rectangular conductor can be limited, and the number of rectangular conductors contained in each combined conductor layer group can be adjusted according to the fixed aspect ratio.

Compared with the related technology, the flat-wire motor with mixed conductor arrangement reduces the aspect ratio of each rectangular conductor while ensuring that the total cross-sectional area of the conductors in the stator slot is similar, which is beneficial to the U-shaped wire forming and has better manufacturability Good; at the same time, adjust the length and width of each rectangular conductor in the stator slot, adjust the stator slot shape, use the stator teeth, adjust the radial distance of the stator slot, adjust the inner diameter of the stator, and adjust the stator yoke to make the magnetic field of each part of the stator assembly The dense distribution is reasonable, which improves the slot full rate and the working efficiency of the motor.

As shown in Figure 3 and Figure 8, compared with the related technology, by setting the combined conductor layer group, each original stator slot is provided with 9 layers of rectangular conductors along the radial direction of the stator core, which is optimized for each stator slot Inside, only 5 layers of rectangular conductors need to be set along the radial direction of the stator core.

In stator slots with unequal widths, the number of conductors in the combined conductor layer can also be the base number. As shown in Figure 11, they are arranged in sequence along the radial direction of the stator core 1, followed by a combined conductor layer consisting of one layer of three conductors, four A combined conductor layer consisting of two conductors and an independent conductor layer.

The technical solution of the embodiment of the present application reduces the requirements for the twisting tool, and the more conductor layers in the stator slot along the radial direction of the stator core, the better the effect of the mixed conductor arrangement proposed by the present application. The production difficulty or cost of the motor is greatly reduced.

As shown in FIG. 12 , the stator slots are set at equal widths, and the stator slots are provided with three combined conductor layer groups 4 and two independent conductor layer groups 5 , accommodating 8 rectangular conductors in total. The dimensions of the rectangular conductors in the three-layer composite conductor layer group 4 are all the same, and the dimensions of the rectangular conductors in the two independent conductor layer groups 5 are all the same, so the windings in the slots are only divided into two types. For stator slots of equal width, the method of multi-line arrangement in the same slot layer of the present application not only optimizes the number of conductor layers along the radial direction of the stator core, but also optimizes the types of lines, further reducing the difficulty of the production process.

The applicant found that when the traditional flat wire motor adopts the design of equal slot width, the shape of the teeth for magnetic conduction in the stator is trapezoidal, and the tooth width is the smallest near the inner circle of the iron core, and the tooth width is the smallest near the outer circle. The width is the largest. This design results in a very uneven magnetic density distribution on the teeth. When the magnetic density of the teeth near the inner circle is very saturated, the magnetic density of the teeth near the outer circle is very low, which is a waste of space.

When the stator slot adopts the traditional one layer of wire per layer space and adopts the stepped slot design, the width of the wire near the outer circle is much higher than that of the wire near the inner circle, and the thickness of the wire near the outer circle is obviously thinner than that near the inner circle. location of the wire. The width-to-thickness ratio of the wire near the outer circle is too large. On the one hand, the insulating layer area of the wire in the slot is too large, sacrificing the pure copper filling rate of the slot; If the bending radius is too large, the end dimension of the winding will be significantly longer than the parallel slot when the stepped slot design is adopted.

In the technical solution of the present application, two or more conductors on the same layer at the bottom of the stator slot are designed to replace the originally required over-flat shape (too large in width-to-thickness ratio) conductors with partial square conductors to improve the fullness of the pure copper slot and effectively reduce the Winding end dimensions. When the stepped slot structure is adopted, the effect of the trapezoidal slot of the slot is realized, the motor wires are arranged in a square shape, and the uniform distribution of the magnetic density of the teeth can be realized, and the space utilization rate of the motor is further greatly improved.

Another embodiment of the present application provides a low-slot pressure drop stator assembly and a motor based on a double split structure, and the motor includes a stator assembly.

Specifically, the stator assembly includes a stator core and a stator winding. Several stator slots are arranged on the stator core along its circumferential direction. The stator winding is a three-phase winding, and its winding adopts a rectangular wire, and the winding The wires are laid out in the form of lapped windings.

Two rectangular wires are arranged in the wire layer at the bottom of each stator slot, and the two rectangular wires are arranged in sequence along the circumferential direction of the stator core, that is, a double-split structure.

Specifically, in the same stator assembly, the naming directions of the wires in each stator slot are the same. Wherein, several layers of wire layers are sequentially arranged in each stator slot along the radial direction of the stator iron core, and the wire layer at the bottom of the slot is the layer of wire layers closest to the outer wall of the stator iron core in the designated sub-slot.

Exemplarily, as shown in Figure 13, there are 5 layers of wire layers and 8 wires arranged in the stator slot. For the convenience of understanding, the wires are named in sequence according to the direction from the bottom of the slot to the slot opening and from left to right. are L1, L2, L3, ..., L8. Wherein, the wire L1 and the wire L2 are arranged in the wire layer at the bottom of the slot.

Further, the stator assembly is provided with n pairs of poles, and each pole includes six stator slots, wherein, n is an even number greater than or equal to 4; each phase winding includes two branches, denoted as branch one and branch Road 2: The first and last ends of the two branches come out from the conductor layer at the bottom of the slot, and the first ends of the two branches are located in the same pole; the windings of the two branches extend in opposite directions on the circumference of the stator core.

The three-phase winding star point line and the winding lead-out line are drawn from the bottom winding of the slot, which creates conditions for the internal connection and external connection of the motor winding without occupying axial space.

Exemplarily, as shown in FIG. 14 , for the convenience of understanding, the winding expansion diagram is sequentially named from left to right: P1, P2, P3, . . . , P2n. Wherein, the head ends of the two branches in the one-phase winding are both located at the P1 pole.

Each pole includes six stator slots, ie each pole includes two slots per phase. As shown in Figure 15, stator slot No. 37 and stator slot No. 38 belong to the same pole and phase. For the convenience of understanding, the two stator slots with the same pole and phase can be named Q1 slot and Q2 slot respectively according to the direction from left to right in the figure. For example, the No. 37 stator slot is the Q1 slot; the No. 38 stator slot is the Q2 slot. In the same stator assembly, the naming direction of each pole slot is the same.

It can be understood that the smallest equalization unit refers to a sub-winding structure composed of winding elements of different phases, ie layers. A branch winding of a motor phase winding has several such sub-winding structures in series, and as long as the number of sub-windings connected in series is equal between different branches, then the phase winding of the motor can be ensured. The windings of the motor are the same in phase and inductance (that is, the motor winding is a balanced winding)

Specifically, a minimum equalization unit is composed of four stacked winding coil units connected in series, and its winding spans three consecutive poles, and all the wires in the slots of a minimum equalization unit are combined according to the slot levels to meet the requirements of four complete stators. slot space.

Exemplarily, as shown in Figure 16, the four stacked winding coil units contained in a minimum equalization unit are: the winding between the No. 26 stator slot and the No. 32 stator slot, the No. 31 stator slot and the No. 37 stator slot The winding between the No. 32 stator slot and the No. 38 stator slot, the winding between the No. 37 stator slot and the No. 43 stator slot. And the winding of the smallest equalization unit spans three poles between the No. 26 stator slot and the No. 43 stator slot.

Specifically, the wires in the slots passed by each stacked winding coil unit are combined to satisfy a complete stator slot space. For example, for the winding between No. 26 stator slot and No. 32 stator slot, the wires in the slot passing through the No. 26 stator slot are L2, L3, L4, and L7; the wires passing through the No. 32 stator slot are L1 , L5, L6, L8; after the wires in the two stator slots are merged according to the wire numbers, it just corresponds to the position of 8 wires in a complete slot. In the same way, for the corresponding wires in the slots of the other stacked coil units, after combining them according to the numbers of the wires, they also just correspond to the positions of the 8 wires in a complete slot.

The winding mode of the winding is changed by using the double wire layout of the wire layer at the bottom of the stator slot, so that the windings of the two branches in the same phase winding extend in opposite directions along the circumference of the stator core. In addition, the two branches in the same phase winding have the same number of minimum equalization units connected in series, so that the phase winding reaches a balanced circuit state.

In addition, the winding heads of the two branches are set in the same stator slot or in the same pole, and the winding head and end of one branch span enough stator slots to realize the reduction of the stator slot. The effect of the highest slot pressure drop between all conductors.

It should be noted that the head end and the end are relative names, that is, one end of the branch winding is the head end, and the other end is the end end, which is not specifically limited.

Further, the minimum equalization unit is divided into a first minimum balance unit and a second minimum balance unit; the windings of the first minimum balance unit and the second minimum balance unit extend in opposite directions on the circumference of the stator core. For two branches in the same phase winding, a minimum equalization unit is used in each branch. That is, two branches in the same phase winding (set as branch 1 and branch 2 for the convenience of description), branch 1 is composed of several first minimum equalization units connected in series, and branch 2 is composed of several second minimum equalization units The units are connected in series.

Since the windings of the two branches in the same phase winding have the same number of minimum equalization units connected in series, the slots passed by the two branches are the same, and they are mutually balanced windings.

For the convenience of understanding, the wire in the slot is defined as PnQcLm, which means the Lm wire in the Qc slot under the Pn pole. Wherein, n≥4, and n is an even number; c is equal to 1 or 2; m≥4.

Exemplarily, when m is an even number, the winding path of a first minimum equalization unit in branch one is:

P1Q2L2 (head)->P2Q2L1->P1Q2L3->...->P1Q2L(m-1)->P2Q2Lm->P3Q2Lm->P2Q2L(m-1)->P3Q2L(m-)...>P1Q2Lm->P2Q2L3- >P3Q2L1->P2Q1L2->P3Q1L2->P4Q1L1->P3Q1L3->…->P3Q1L(m-1)->P4Q1Lm->P3Q1Lm->P2Q1L(m-1)->P3Q1L(m-2)->… -> P2Q1L3 -> P3Q1L1 -> P2Q2L2 (end) -> (another first minimum equalization unit head end).

The winding path of a second minimum equalization unit in branch two is:

P1Q1L2->P2Q1L1->P1Q1L3->...->P1Q1L(m-1)->P2Q1Lm->P1Q1Lm->P(2n)Q1L(m-1)->P1Q1L(m-2)->...->P (2n)Q1L3->P1Q1L1->P(2n)Q2L2->P(2n-1)Q2L2->P(2n)Q2L1->P(2n-1)Q2L3->...P(2n-1)Q2L( m-1)->P(2n)Q2Lm->P1Q2Lm->P(2n)Q2L(m-1)->P1Q2L(m-3)->...->P(2n)Q2L3->P1Q2L1->P (2n) Q1L2->(another second minimum equalization unit head end).

When m is an odd number, the winding path of a first minimum equalization unit in branch one is:

P1Q2L2->P2Q2L1->P1Q2L3->…->P1Q2Lm->P2Q1Lm->P3Q1L(m-1)->…->P2Q1L3->P3Q1L1->P2Q1L2->P3Q1L2->P4Q1L1->P3Q1L3->…-> P3Q1Lm->P2Q2Lm->P3Q2L(m-1)->P2Q2Lm->P3Q2L(m-1)->...->P2Q2L3->P3Q2L1->P2Q2L2->(another first minimum equalization unit head end).

The winding path of a second minimum equalization unit in branch two is:

P1Q2L1 (head end)->P2Q1L1->P1Q1L3->…->P1Q1Lm->P(2n)Q2Lm->P1Q2L(m-1)->…->P(2n)Q2L3->P1Q1L2->P(2n )Q1L2->P(2n-1)Q1L2->P(2n)Q2L1->P(2n-1)Q2L3->...P(2n-1)Q2Lm->P(2n)Q1Lm->P1Q1L(m- 1)->...->P(2n)Q1L3->P1Q1L1->P(2n)Q2L2 (end)->(the head end of another second minimum equalization unit).

As shown in Figure 17, when the stator assembly has 8 poles and 48 slots, and the number of branches is 2, in the same phase winding, branch one is connected in series by two first minimum equalization units, and branch two is composed of two second minimum equalization units. Units are connected in series. In this way, half of the windings of the two branches share the same slot, and the slot voltage drop of the motor is reduced by half.

When the stator assembly has 12 poles and 72 slots, and the number of branches is 2, in the same phase winding, branch one is connected in series with three first minimum equalization units, and branch two is connected in series with three second minimum balance units. In this way, half of the windings of the two branches share the same slot, and the slot voltage drop of the motor is reduced to less than 1/3. By analogy this time, the more the number of pole slots of the motor, the greater the slot pressure drop.

When m is an even number, and in the same phase winding, the head ends of the two branches are located in the same stator slot.

Exemplarily, the winding path of a first minimum equalization unit in branch one is: P1Q2L2->P2Q2L1->P1Q2L3->...->P1Q2L(m-1)->P2Q2Lm->P3Q2Lm->P2Q2L(m- 1)->P3Q2L(m-2)->…>P2Q2L3->P3Q2L1->P2Q1L2->P3Q1L2->P4Q1L1->P3Q1L3->…->P3Q1Lm->P2Q1L(m-1)->P3Q1L(m- 2)->P2Q1L3->P3Q1L1->P2Q2L2->(another first minimum unit unit head end).

The winding path of a second smallest equalization unit in branch two is: P1Q2L1->P2Q1L1->P1Q1L3->...->P1Q1Lm->P(2n)Q2L(m-1)->P1Q2L(m-2)- >…->P(2n)Q2L3->P1Q1L2->P(2n)Q1L2->P(2n-1)Q2L2->P(2n)Q2L1->P(2n-1)Q2L3->…P(2n -1) Q2L(m-1)->P(2n)Q2Lm->P1Q2Lm->P(2n)Q1L(m-1)->P1Q1L(m-2)->...->P(2n)Q1L3- >P1Q1L1->P(2n)Q2L2->(the head end of another second minimum equalization unit).

The head ends of the two branches are set in the same stator slot, the windings extend oppositely, and the ends of the two branches are located in the same slot with different poles.

When the stator assembly has 8 poles and 48 slots, the number of branches is 2, the head ends of each branch are in the same stator slot, and the sequence of the smallest equalization unit is similar in series, each branch reduces the voltage drop of two stacked coil units, The maximum tank pressure drop can be further reduced to within 1/4 phase pressure drop.

It should be noted that the similar series sequence of the minimum equalization units of the two branches in the same phase means that the two branches follow the sequence of circuit connection, the positions of the coil units of each stacked winding, and the law of voltage drop change at the beginning and end of the branches are the same.

In the same phase winding, the two branch windings have four beginnings and ends, and the two beginnings or ends with the closest distance are set as lead-out lines, and the remaining two are set as star-point lines. In this way, the outgoing wires of the three-phase windings can be controlled within the range of one pole, reducing the occupied angular space.

The beneficial effect of this application is:

1. In the stator assembly proposed in this application, the double wire layout at the bottom of the stator slot is used to change the winding mode of the winding, so that the winding of the two branches in the same phase winding follows the circumferential direction of the stator core. extend in the opposite direction. In addition, the two branches in the same phase winding have the same number of minimum equalization units connected in series, so that the phase winding reaches a balanced circuit state.

2. Set the winding heads of the two branches in the same stator slot or in the same pole, and between the winding heads and ends of a branch, span enough stator slots to reduce the stator slot. The effect of the highest slot pressure drop between all conductors.

3. The three-phase winding star point line and the winding lead-out line are drawn from the bottom winding of the slot, which creates conditions for the internal connection and external connection lines of the motor winding to not occupy the axial space.

Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that: they can still modify the technical solutions described in the aforementioned embodiments, or perform equivalent replacements for some of the technical features; and these The modification or replacement does not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present application.

Claims

A stator assembly, the stator assembly includes a stator core and a stator winding; the stator core is substantially cylindrical; a number of stator slots are arranged on the stator core, and the stator slots are arranged along the The circumferential direction of the stator cores is arranged sequentially in a circular array; the winding of the stator winding adopts a rectangular conductor, wherein,

Each stator slot is provided with several layers of combined conductor layer groups, and each layer of combined conductor layer groups in the same stator slot is arranged in sequence along the radial direction of the stator core;

Each group of combined conductor layers includes two or more rectangular conductors, and each group of rectangular conductors is arranged in sequence along the circumferential direction of the stator core.
A stator assembly according to claim 1, wherein the aspect ratio of the rectangular conductors in the composite conductor layer group is not more than 2.5.
The stator assembly according to claim 1, wherein the stator slots are provided with even-numbered composite conductor layers, or the stator slots are provided with odd-numbered composite conductor layers.
A stator assembly according to claim 1, wherein one or more independent conductor layers are further arranged in each of the stator slots, and each independent conductor layer group contains only one rectangular conductor;

The combined conductor layer group and the independent conductor layer group in the same stator slot are arranged in sequence along the radial direction of the stator core; the independent conductor layer group is set close to the center of the stator core, and the combined conductor layer group is close to the outer wall of the stator core set up.
A stator assembly according to claim 4, wherein the aspect ratio of the rectangular conductors in the independent conductor layer group does not exceed 3.
A stator assembly according to claim 1, wherein the stator winding includes one or more independent branches; in the same independent branch, rectangular conductors located in different conductor layer groups are connected in series.
The stator assembly according to any one of claims 4-6, wherein the group of combined conductor layers comprises an even number of rectangular conductors, and the independent conductor layers are even layers.
The stator assembly according to claim 4-7, wherein the combined conductor layer set close to the outer wall of the stator core includes two rectangular wires, and n pairs of poles are arranged on the stator assembly, and each pole includes six stator slots , wherein, n is an even number greater than or equal to 4;

Each phase winding of the stator winding includes two branch circuits, the first and the end of the two branch circuits come out from the wire layer at the bottom of the slot, and the first ends of the two branch circuits are located in the same pole; the windings of the two branch circuits are in the The directions extending on the circumference of the stator core are opposite.
The stator assembly according to claim 8, wherein each branch is composed of several minimum equalization units in series, and the number of minimum equalization units connected in series in two branches in the same phase winding is the same.
The stator assembly according to claim 9, wherein one minimum equalization unit is composed of four stacked winding coil units in series, and its winding wire spans three consecutive poles, and all the wires in the slots of one minimum equalization unit are arranged according to After the slot levels are merged, four complete stator slot spaces are satisfied.
The stator assembly according to claim 9, wherein the minimum equalization unit comprises a first minimum equalization unit and a second minimum equalization unit; the windings of the first minimum equalization unit and the second minimum equalization unit have The direction of upward extension is opposite;

For two branches in the same phase winding, a minimum equalization unit is used in each branch.
The stator assembly according to any one of claims 8-11, wherein the head ends of the two branches in the winding of the same phase are located in the same stator slot.
The stator assembly according to any one of claims 8-11, wherein, in the windings of the same phase, the two branch windings have four starting ends, and the two starting ends or ends that are closest to each other are set as lead-out wires , and the remaining two are set as star-dotted lines.
A flat wire motor with multiple wires in the same slot layer, which includes a rotor assembly and a stator assembly according to any one of claims 1-13, and the rotor assembly is located inside the stator assembly.