WO2024185063A1

WO2024185063A1 - Stator and rotary electrical machine

Info

Publication number: WO2024185063A1
Application number: PCT/JP2023/008761
Authority: WO
Inventors: 正克松原; 佑将松岡; 大介森; 直哉佐々木; 大翔田中
Original assignee: 株式会社東芝; 東芝インフラシステムズ株式会社
Priority date: 2023-03-08
Filing date: 2023-03-08
Publication date: 2024-09-12

Abstract

A stator according to an embodiment of the present invention comprises: a stator iron core in which are formed a plurality of stator slots; and a stator winding which, for each phase, is provided with a plurality of coil segments and a plurality of crossover parts, said plurality of coil segments each having rectilinear parts which use a rectangular conductor and which are respectively accommodated in two differing stator slots, and a connection part which uses a rectangular conductor and which connects two rectilinear parts outward of a first end part of the stator iron core in the axial direction, said plurality of crossover parts connecting the plurality of coil segments in series outward of a second end part of the stator iron core in the axial direction. The plurality of rectilinear parts form, in each of the plurality of stator slots and in the radial direction, N layers (where N is an even number of four or more). Series portions that are respectively formed by a first layer and a second layer which are adjacent to each other form parallel portions (135) with each other, and connection is made with a third layer adjacent to the second layer or the first layer.

Description

Stator and rotating motor

The present invention relates to a stator and a rotating electric machine.

In electric motors and generators used in EVs (electric vehicles) and PEVs (plug-in electric vehicles), large currents flow through the stator windings, so rectangular wire with a large cross-sectional area is used as the conductor for the stator windings.

When using rectangular wire, the conventional method is to form the stator winding using multiple coil segments. Here, the coil segment is composed of a pair of straight sections that are housed in the stator slots and a connecting section that connects them.

International Publication No. 2021/250790 Patent No. 6156268 Utility Model Publication No. 59-132373

When using this coil segment, the number of rectangular conductors arranged radially in each stator slot must be an even number, and cannot be an odd number.

On the other hand, the number of coil turns is one of the important parameters when adjusting the electromagnetic performance of the stator winding. For this reason, there was a need for a method that would allow the number of coil turns to be an odd number, even when coil segments are used.

The object of the present invention is to provide a stator and rotating electric machine that can obtain a stator winding with an odd number of turns with a simple configuration, even when using coil segments made of rectangular wire.

In order to achieve the above-mentioned object, the stator according to an embodiment of the present invention is a stator comprising: a cylindrical stator core with multiple stator slots formed in the circumferential direction on its inner surface; multiple coil segments each having a straight section with a rectangular cross section accommodated in two different stator slots and a connecting section with a rectangular cross section connecting the two straight sections outside a first axial end of the stator core; and a stator winding for each phase, each having multiple jumper sections connecting the multiple coil segments in series outside a second axial end of the stator core, wherein the multiple straight sections form N layers (N is an even number equal to or greater than 4) in the radial direction in each of the multiple stator slots, and two adjacent layers are connected in parallel to the layers adjacent to them.

1 is a vertical cross-sectional view illustrating an example of a rotating electric machine according to a first embodiment. 1 is a cross-sectional view showing an example of a rotor of a rotating electric machine according to a first embodiment; FIG. 2 is a partial cross-sectional view showing the state of a straight portion in a stator slot of the stator according to the first embodiment. FIG. 11 is a connection diagram showing a connection state between straight portions of each layer in each slot of a stator winding in a conventional example for comparison with the first embodiment. FIG. 4 is a connection diagram showing a connection state between straight portions of each layer in each slot of a stator winding of the stator according to the first embodiment. FIG. 2 is a connection diagram of a stator winding of a stator according to the first embodiment. FIG. 11 is a connection diagram showing a connection state between straight portions of each layer in each slot of a stator winding in a conventional example for comparison with the second embodiment. FIG. 11 is a connection diagram showing a connection state between straight portions of each layer in each slot of a stator winding of a stator according to a second embodiment. FIG. 11 is a connection diagram of a stator winding of a stator according to a second embodiment.

Below, a stator and a rotating electric machine according to an embodiment of the present invention will be described with reference to the drawings. Here, identical or similar parts are given common reference numerals and duplicated explanations will be omitted.

[First embodiment]
FIG. 1 is a vertical cross-sectional view illustrating an example of a rotating electric machine according to a first embodiment.

FIG. 1 is a vertical cross-sectional view showing an example of a rotating electric machine 1 having a stator 100 according to an embodiment.

The rotating electric machine 1 comprises a rotor 10, a bearing 21, a bearing bracket 22, a frame 23, and a stator 100.

The rotor 10 has a rotor shaft 11 extending in the direction of the rotation axis CL, a rotor core 12 attached radially outside the rotor shaft 11, permanent magnets 13 embedded in the rotor core 12, and closure plates 14 provided on both axial ends of the rotor core 12 to prevent the permanent magnets 13 from protruding. The rotor shaft 11 is rotatably supported by bearings 21 on both axial sides. Each bearing 21 is supported stationary by a bearing bracket 22.

The stator 100 has a stator core 110 arranged radially outside the rotor core 12 with a gap between them, and a stator winding 120 partially housed within a stator slot 111 (Fig. 2) formed in the stator core 110 and wound around stator teeth 112 (Fig. 2).

The stator 100 is housed within a frame 23 arranged to surround the radial outside and is supported stationary by the frame 23.

The stator winding 120 has multiple coil segments 130 and multiple transition sections 125 that connect them.

Here, the coil segment 130 has two straight sections 131 that are respectively housed in two different stator slots 111, and a connection section 132 that connects these two straight sections 131 axially outside the first end 110a of the stator core 110. Each straight section 131 is respectively housed in the stator slot 111, and both ends of the straight section 131 protrude axially outside the first end 110a and second end 110b of the stator core 110.

The crossover portion 125 connects the straight portions 131 of the coil segments 130 that protrude axially outward from the second end portion 110b.

FIG. 2 is a cross-sectional view showing an example of the rotor 10 of the rotating electric machine 1 according to the first embodiment.

The rotor 10 shown in FIG. 2 has two permanent magnets 13 housed in the rotor core 12 at each magnetic pole. Note that the rotor 10 shown in FIG. 2 is an example, and the stator 100 and rotating electric machine 1 according to this embodiment can also be applied to rotors of other types.

FIG. 3 is a partial cross-sectional view showing the state of the straight portion 131 in the stator slot 111 of the stator 100 according to the first embodiment.

The radial inner surface of the stator core 110 is formed with a number of stator slots 111, which are axial through grooves spaced apart from one another in the circumferential direction and extending in the axial direction. The stator slots 111 are also formed so as to be adjacent to one another in the circumferential direction, thereby forming stator teeth 112.

In each stator slot 111, multiple flat conductors with rectangular cross sections, which are the straight sections 131 of the coil segments 130, are stacked radially while being electrically insulated from each other. When the stator winding 120 is formed by the coil segments 130 and the jumper sections 125, the number N of stacked straight sections 131 in each stator slot 111 is an even number.

In other words, in the example shown in FIG. 3, in each stator slot 111, the first layer conductor 131a, the second layer conductor 131b, the third layer conductor 131c, the fourth layer conductor 131d, the fifth layer conductor 131e, and the sixth layer conductor 131f are arranged in this order from the outside to the inside in the radial direction. That is, in this case, the number of layers N is 6. Hereinafter, regardless of the stator slot 111, these rectangular conductors that are the straight portions 131 will be referred to as the nth layer conductor (n=1 to N) according to the order of the layers. In the example shown in FIG. 2, they are the first layer conductor 131a, the second layer conductor 131b, the third layer conductor 131c, the fourth layer conductor 131d, the fifth layer conductor 131e, and the sixth layer conductor 131f.

The radial thickness t0 of the first layer conductor 131a, the second layer conductor 131b, the third layer conductor 131c, and the fourth layer conductor 131d is substantially the same. On the other hand, the radial thickness t1 of the fifth layer conductor 131e and the sixth layer conductor 131f, which correspond to the parallel portion 135 (FIG. 6) described below, is substantially half of t0. Furthermore, within the range of the parallel portion 135, the thickness of not only the straight portion 131 but also the connection portion 132 and the transition portion 125 is half of t0.

Here, "substantially the same" means that the dimensions are the same in terms of design and match within the range of manufacturing error, and "substantially one-half" means that the dimensions are one-half of t0 in terms of design and one-half within the range of manufacturing error. Here, manufacturing error includes errors in processing, assembly, measurement, etc.

To make it easier to understand the features of this embodiment, we will first explain a conventional connection example.

4 is a connection diagram showing the connection state between the straight portions 131 of each layer in each slot of the stator winding in a conventional example for comparison with the first embodiment. The horizontal direction of the squares shown in FIG. 4 indicates the number of the stator slot 111 as written in the top row. The vertical direction indicates the first to sixth layers from top to bottom. The symbols written in each square indicate the number of the straight portion 131 of the coil segment 130 of each layer in each stator slot 111. The solid lines connecting the straight portions 131 indicate the jumper portion 125. The dashed lines connecting the straight portions 131 indicate the connection portion 132. In other words, the dashed lines indicate the winding conductor 121 arranged on the axial outside of the first end 110a of the stator core 110, and the solid lines indicate the winding conductor 121 arranged on the axial outside of the second end 110b of the stator core 110. The same applies to FIGS. 5, 7, and 8 described later.

The straight portion 131 indicated by 1u in the first layer of the 48th slot is connected to a lead wire 141 that connects to the outside of the stator winding on the axial outside of the first end 110a of the stator core 110. The straight portion 131 indicated by 96u in the first layer of the 7th slot is connected to a neutral line 142 on the axial outside of the first end 110a of the stator core 110. For ease of explanation, the straight portion 131 indicated by 1u is represented as the straight portion 1u, and the straight portion 131 indicated by 96u is represented as the straight portion 96u.

In FIG. 4, the U-phase coil segment 130 is shown, and the U-phase coil segment 130 is connected in series from the straight section 1u connected to the lead wire 141 to the straight section 96u connected to the neutral line 142 by the connection section 132 and the crossover section 125. The

numbers

1u, 96u, etc. indicate the order in which the straight sections 131 are connected.

In Figure 4, an example is shown for a 3-phase, 8-pole rotor with 2 slots per phase per pole, for a total of 48. Therefore, in the case of full-pitch winding, the slot spacing is 6.

In the conventional example, for example, there are six slots from straight section 5u (slot no. 24) to straight section 6u (slot no. 30). Thus, in FIG. 4, there are six slots between the jumper section 125 shown by the solid line and the connection section 132 shown by the dashed line, i.e., a full pitch winding.

The above is an explanation of the U-phase, but the straight sections 131 of the V-phase are positioned at positions where the slot number is increased by two, and the straight sections 131 of the W-phase are positioned at positions where the slot number is increased by four.

FIG. 5 is a connection diagram showing the connection state between the straight portions 131 of each layer in each slot of the stator winding of the stator according to the first embodiment.

For comparison with the conventional method, the example shown in Figure 5 is for a 3-phase, 8-pole rotor with 2 slots per phase per pole, for a total of 48. Therefore, in the case of full-pitch winding, the slot spacing is 6.

As shown in Figure 5, the first to third layers are connected in the same way as in the conventional example. The fourth to sixth layers differ from the conventional example shown in Figure 4. The differences are explained below.

In the conventional example shown in FIG. 4, the straight portion 64u of the fourth layer of the 43rd slot is connected only to the straight portion 65u of the fifth layer of the first slot by the transition portion 125. The straight portion 81u of the fourth layer of the first slot is connected only to the straight portion 80u of the fifth layer of the seventh slot.

On the other hand, in the present embodiment shown in FIG. 5, the straight portion 32u of the fourth layer of the 43rd slot is connected to both the straight portion 33u of the fifth layer of the 48th slot and the straight portion 33u of the sixth layer of the 48th slot by the jumper portion 125. That is, the straight portion 32u of the fourth layer branches into two straight portions 33u whose radial thickness is half that of the fifth and sixth layers. Also, the straight portion 49u of the fourth layer of the first slot is connected to both the straight portion 48u of the fifth layer of the seventh slot and the straight portion 48u of the sixth layer of the 43rd slot. That is, the two straight portions 48u whose radial thickness is half that of the fifth and sixth layers are integrated with the straight portion 49u of the fourth layer. Therefore, the first portion 135a (FIG. 6) from the straight portion 33u of the fifth layer of the 48th slot to the straight portion 48u of the sixth layer of the 43rd slot, and the second portion 135b (FIG. 6) from the straight portion 33u of the sixth layer of the 48th slot to the straight portion 48u of the fifth layer of the seventh slot are parallel portions 135 (FIG. 6) that are electrically parallel to each other.

Furthermore, the first portion 135a from the straight portion 33u in the fifth layer of the 48th slot to the straight portion 48u in the sixth layer of the 43rd slot is connected in a direction in which the slot number increases, whereas the second portion 135b from the straight portion 33u in the sixth layer of the 48th slot to the straight portion 48u in the fifth layer of the 7th slot is connected in a direction in which the slot number decreases. In other words, the first portion 135a and the second portion 135b are connected in opposite directions.

FIG. 6 is a connection diagram of the stator winding 120 of the stator 100 according to the first embodiment. One straight section 32u branches into two straight sections 33u, and then the two straight sections 48u are integrated into one straight section 49u. The two parallel sections, i.e., straight section 33u to straight section 48u, are arranged in the fifth and sixth layers.

The above has been described with an example in which the fifth and sixth layers have parallel parts arranged and are connected to the fourth layer, but this is not limiting. It is sufficient to arrange parallel parts in two of three adjacent layers. That is, for n≧3, among the n layer, (n-1) layer, and (n-2) layer, the n layer and the (n-1) layer may be connected to the (n-2) layer as parallel parts, or the (n-1) layer and the (n-2) layer may be connected to the n layer as parallel parts.

As described above, in this embodiment, for the stator winding 120 using flat rectangular conductors stacked in a number of layers N, two adjacent layers are made into parallel portions 135 that are electrically parallel to each other, thereby achieving an electrically odd number of turns.

In addition, by making the thickness t1 of the layer conductor of the parallel portion 135 half the thickness t0 of the other layer conductors, the current density of each conductor can be made approximately the same.

Furthermore, as illustrated in this embodiment, by forming parallel portions 135, in which the thickness t1 of the rectangular conductor is half the thickness t0 of the rectangular conductor in the other layers, as the innermost layer and the layer outside it, it is possible to reduce eddy current loss due to magnetic flux linking the layer conductors.

Second Embodiment
FIG. 7 is a connection diagram showing a connection state between straight portions of each layer in each slot of a stator winding in a conventional example for comparison with the second embodiment.

In FIG. 7, the straight portion 131 indicated by 1u in the first layer of the first slot is connected to a lead wire 141 that connects to the outside of the stator winding on the axial outside of the first end 110a of the stator core 110. Also, the straight portion 131 indicated by 96u in the first layer of the 42nd slot is connected to a neutral line 142 on the axial outside of the first end 110a of the stator core 110.

The U-phase coil segment 130 shown in FIG. 7 is connected in series from the straight section 1u connected to the lead wire 141 to the straight section 96u connected to the neutral line 142 by the connection section 132 and the jumper section 125.

In the conventional example, for example, there are six slots between the straight portion 43u of the second layer of the 24th slot and the straight portion 42u of the first layer of the 30th slot (solid line portion), and there are also six slots between the straight portion 91u of the second layer of the 25th slot and the straight portion 90u of the first layer of the 31st slot (solid line portion). In other words, it is a full-pitch winding.

On the other hand, for example, there are five slots between the straight line portion 5u of the first layer of the 25th slot and the straight line portion 6u of the second layer of the 30th slot (dashed line portion). Also, there are seven slots between the straight line portion 53u of the first layer of the 24th slot and the straight line portion 54u of the second layer of the 31st slot (dashed line portion).

As such, in the conventional example shown in Figure 7, the transition section 125 shown by the solid line is a full-pitch winding, while the connection section 132 shown by the dashed line is not a full-pitch winding, but rather has a mixture of longer and shorter pitches.

FIG. 8 is a connection diagram showing the connection state between the straight sections of each layer in each slot of the stator winding of the stator according to the second embodiment.

For comparison with the conventional method, the example shown in Figure 8 is for a 3-phase, 8-pole rotor with 2 slots per phase per pole, for a total of 48. Therefore, in the case of full-pitch winding, the slot spacing is 6.

As shown in Figure 8, the first to third layers are connected in the same way as in the conventional example. The fourth to sixth layers differ from the conventional example shown in Figure 7. The differences are explained below.

In the conventional example shown in FIG. 7, the straight line portion 16u in the fourth layer of the 43rd slot is connected only to the 17u in the fifth layer of the 1st slot by the jumper portion 125. The straight line portion 33u in the fourth layer of the 37th slot is connected only to the 32u in the fifth layer of the 43rd slot by the jumper portion 125. The straight line portion 60u in the fourth layer of the 18th slot is connected only to the 61u in the third layer of the 24th slot by the jumper portion 125. In addition, the straight line portion 85u in the fourth layer of the 12th slot is connected only to the 86u in the third layer of the 7th slot by the jumper portion 125.

On the other hand, in this embodiment shown in Figure 8, the same parts are as follows:

In this embodiment, the straight portion 16u of the fourth layer of the 43rd slot is connected to both the straight portion 17u of the fifth layer of the 48th slot and the straight portion 17u of the fifth layer of the first slot by a transition portion 125. In other words, the straight portion 16u of the fourth layer branches into two straight portions 17u with a radial thickness that is half that of the fifth layer.

The straight portion 25u of the fourth layer of the 37th slot is connected to both the straight portion 24u of the fifth layer of the 42nd slot and the straight portion 24u of the fifth layer of the 43rd slot by the transition portion 125. In other words, the two straight portions 24u of the fifth layer, which have a radial thickness that is half, are integrated with the straight portion 25u of the fourth layer.

The straight portion 56u of the fourth layer of the 18th slot is connected to both the straight portion 57u of the fifth layer of the 24th slot and the straight portion 57u of the fifth layer of the 25th slot by a transition portion 125. In other words, the straight portion 56u of the fourth layer branches into two straight portions 57u with a radial thickness that is half that of the fifth layer.

The straight portion 65u of the fourth layer of the 12th slot is connected to both the straight portion 64u of the fifth layer of the 18th slot and the straight portion 64u of the fifth layer of the 19th slot by the transition portion 125. In other words, the two straight portions 64u of the fifth layer, which have a radial thickness that is half, are integrated with the straight portion 65u of the fourth layer.

In the configuration described above, the first portion 136a (FIG. 9) from the straight portion 17u of the fifth layer of the 48th slot to the straight portion 24u of the fifth layer of the 42nd slot, and the second portion 136b (FIG. 9) from the straight portion 17u of the fifth layer of the 1st slot to the straight portion 24u of the fifth layer of the 43rd slot are parallel portions 136 (FIG. 9) that are electrically parallel to each other. Also, the first portion 137a (FIG. 9) from the straight portion 57u of the fifth layer of the 24th slot to the straight portion 64u of the fifth layer of the 18th slot, and the second portion 137b (FIG. 9) from the straight portion 57u of the fifth layer of the 25th slot to the straight portion 64u of the fifth layer of the 19th slot are parallel portions 137 (FIG. 9) that are electrically parallel to each other.

Furthermore, in the parallel portion 136, the first portion 136a and the second portion 136b are connected in the opposite directions. In the parallel portion 137, the first portion 137a and the second portion 137b are also connected in the opposite directions.

FIG. 9 is a connection diagram of the stator windings of the stator according to the second embodiment. In the parallel portion 136, one straight portion 16u branches into two straight portions 17u, and then the two straight portions 24u are integrated into one straight portion 25u. In the parallel portion 137, one straight portion 56u branches into two straight portions 57u, and then the two straight portions 64u are integrated into one straight portion 65u. Furthermore, the straight portions in the two

parallel portions

136 and 137 are arranged in the fifth and sixth layers.

The above describes an example in which parallel portions are arranged on the fifth and sixth layers and connected to the fourth layer, but this is not limiting. As described in the first embodiment, parallel portions may be arranged on two adjacent layers out of three adjacent layers.

As described above, in this embodiment, for the stator winding 120 using flat rectangular conductors stacked in a number of layers N, two adjacent layers are made into parallel portions 135 that are electrically parallel to each other, so that an odd number of turns can be achieved electrically, as in the first embodiment.

Also, by making the thickness t1 of the layer conductor of the parallel portion 135 half the thickness t0 of the other layer conductors, the current density of each conductor can be made approximately the same, and further, as illustrated in this embodiment, by making the parallel portion 135, in which the thickness t1 of the rectangular conductor is half the thickness t0 of the rectangular conductor of the other layers, the innermost layer and the layer outside it, it is possible to reduce eddy current loss due to magnetic flux linking the layer conductors, which is the same as the first embodiment.

In this way, even in the conventional example shown in Figure 7, where the transition section 125 shown by the solid line is a full-pitch winding and the connection section 132 shown by the dashed line is not a full-pitch winding but has a mixture of longer and shorter pitches, an embodiment that produces the same effect as the first embodiment can be realized.

According to the embodiment described above, it is possible to provide a stator and a rotating electric machine that can obtain a stator winding with an odd number of turns using a simple configuration, even when coil segments made of rectangular wire are used.

[Other embodiments]
Although the embodiments of the present invention have been described above, the embodiments are presented as examples and are not intended to limit the scope of the invention. In addition, the features of each embodiment may be combined. Furthermore, the embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. The embodiments and their modifications are included in the scope of the invention and its equivalents as described in the claims, as well as in the scope and gist of the invention.

1...rotating electric machine, 10...rotor, 11...rotor shaft, 12...rotor core, 13...permanent magnet, 14...closure plate, 21...bearing, 22...bearing bracket, 23...frame, 100...stator, 110...stator core, 111...stator slot, 120...stator winding, 125...bridge section, 130...coil segment, 131...straight section, 132...connection section, 135...parallel section, 135a...first section, 135b...second section, 136...parallel section, 136a...first section, 136b...second section, 137...parallel section, 137a...first section, 137b...second section, 141...lead wire, 142...neutral wire

Claims

A cylindrical stator core having a plurality of stator slots formed in a circumferential direction on an inner peripheral surface thereof;
a stator winding including, for each phase, a plurality of coil segments, each of which has a straight portion using a rectangular conductor that is accommodated in each of the two stator slots that are different from each other and a connection portion using a rectangular conductor that connects the two straight portions on the outside of a first axial end of the stator core, and a plurality of jumper portions that connect the plurality of coil segments in series on the outside of a second axial end of the stator core;
A stator comprising:
The straight portions form N layers (N is an even number equal to or greater than 3) in a radial direction in each of the stator slots,
The series portions formed in the first layer and the second layer adjacent to each other form parallel portions, and are connected to a third layer adjacent to the first layer or the second layer.
A stator characterized by:
The first layer and the second layer are, in order from the outermost radial direction in each of the stator slots, an (N-1)th layer and an Nth layer,
The first layer is the (N-1)th layer;
2. The stator according to claim 1 .
The stator of claim 1, characterized in that the radial thickness of the rectangular conductors of the straight sections arranged in the first layer and the second layer and the connecting section connecting them is substantially half the radial thickness of the rectangular conductors of the straight sections arranged in the third layer.
a rotor having a rotor shaft extending in a direction of a rotation axis and a rotor core attached to the rotor shaft and incorporating a permanent magnet;
A stator according to any one of claims 1 to 3;
A rotating electric machine comprising: