JP2017028847A - Stator of rotary electric machine and rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high torque and low noise rotary electric machine.SOLUTION: The rotary electric machine comprises: a stator core having a plurality of slots; coils inserted through the slots; and a rotator which is rotatably supported with respect to the stator core being interposed by a gap. In a layer of a slot group in which coils of the same phase are inserted through, the number of slots in each pole and each phase + N (N is an integer) in-phase coils are arranged.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a stator of a rotating electrical machine and a rotating electrical machine.

  As a winding technique of a rotating electrical machine used for driving a vehicle, a technique as described in Patent Document 1 is known.

JP 2012-29370 A

  By the way, a rotating electrical machine mounted on an electric vehicle or the like is required to have low noise while being high torque. Therefore, an object of the present invention is to provide a rotating electrical machine having high torque and low noise.

  In order to solve the above-described problem, a stator of a rotating electrical machine according to the present invention includes a stator core having a plurality of slots, and a coil inserted through the slots, and a group of slots through which in-phase coils are inserted. In the predetermined layer, when N is an integer equal to or greater than 1, in-phase coils with the number of slots per phase per pole + N or the number of slots per phase per pole−N are arranged.

  ADVANTAGE OF THE INVENTION According to this invention, in the vehicle provided with the rotary electric machine and the rotary electric machine, high torque and low torque ripple can be achieved.

Sectional drawing of a rotary electric machine. Sectional drawing of the stator 230 and the rotor 250. FIG. The perspective view of the stator 230. FIG. Connection diagram of stator winding. The figure which shows the U-phase winding of 1st Embodiment. FIG. 3 is a layout diagram of slot conductors according to the first embodiment. FIG. 6 is a layout diagram of slot conductors in a conventional rotating electrical machine. The torque waveform of the rotary electric machine to which 1st Embodiment is applied, and a comparative example. The figure which shows the modification of 1st Embodiment. The figure which shows the slot conductor arrangement | positioning in one of the modifications of 1st Embodiment. The figure which shows arrangement | positioning of the slot conductor group in 2nd Embodiment. The figure which shows slot conductor arrangement | positioning in one of 2nd Embodiment. The figure which shows arrangement | positioning of the slot conductor group in 3rd Embodiment. The figure which shows slot conductor arrangement | positioning in one of 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description shows specific examples of the contents of the present invention, and the present invention is not limited to these descriptions. Various modifications by those skilled in the art are within the scope of the technical idea disclosed in this specification. Changes and modifications are possible. In all the drawings for explaining the present invention, components having the same function are denoted by the same reference numerals, and repeated description thereof may be omitted.

  FIG. 1 shows a cross-sectional view of the rotating electrical machine 200. A stator 230 is held inside the housing 212, and the stator 230 includes a stator core 232 and a stator winding 238. A rotor 250 is rotatably held on the inner peripheral side of the stator core 232 through a gap 222. The rotor 250 includes a rotor core 252 fixed to the shaft 218, a permanent magnet 254, and a non-magnetic contact plate 226. The housing 212 has a pair of end brackets 214 provided with bearings 216, and the shaft 218 is rotatably held by these bearings 216.

  The shaft 218 is provided with a resolver 224 that detects the position and rotation speed of the pole of the rotor 250. The output from the resolver 224 is taken into a control circuit (not shown).

  Three-phase AC power is supplied to the stator winding 238 from an inverter or power source (not shown), and a rotating magnetic field is generated in the stator 230. The frequency of the three-phase alternating current is controlled based on the output value of the resolver 224, and the phase of the three-phase alternating current with respect to the rotor 250 is also controlled based on the output value of the resolver 224.

  FIG. 2 is a view showing a cross section of the stator 230 and the rotor 250, and shows the AA cross section of FIG. In FIG. 2, the housing 212, the shaft 218, and the stator winding 238 are not shown. On the inner peripheral side of the stator core 232, a large number of slots 237 and teeth 236 are arranged uniformly over the entire circumference. In FIG. 2, all the slots and teeth are not labeled, and only some teeth and slots are represented by symbols. A slot insulating material (not shown) is provided in the slot 237, and a plurality of U-phase, V-phase, and W-phase windings constituting the stator winding 238 in FIG. In this embodiment, 48 slots 237 are formed at equal intervals.

  Further, in the vicinity of the outer periphery of the rotor core 252, a plurality of holes 253 for inserting rectangular magnets are arranged at equal intervals along the circumferential direction. Each hole 253 is formed along the axial direction, and permanent magnets 254 are embedded in the holes 253 and fixed with an adhesive or the like. The circumferential width of the hole 253 is set to be larger than the circumferential width of the permanent magnet 254 (254a, 254b), and the hole spaces 257 on both sides of the permanent magnet 254 function as magnetic gaps. The hole space 257 may be filled with an adhesive, or may be solidified integrally with the permanent magnet 254 with a molding resin. The permanent magnet 254 acts as a field pole of the rotor 250 and has an eight-pole configuration in this embodiment.

  The magnetization direction of the permanent magnet 254 faces the radial direction, and the direction of the magnetization direction is reversed for each field pole. That is, if the stator side surface of the permanent magnet 254a is N-pole and the surface on the shaft side is S-pole, the stator side surface of the adjacent permanent magnet 254b is S-pole and the surface on the shaft side is N-pole. . These permanent magnets 254a and 254b are alternately arranged in the circumferential direction.

  The permanent magnet 254 may be inserted into the hole 253 after being magnetized, or may be magnetized by applying a strong magnetic field after being inserted into the hole 253 of the rotor core 252. However, since the magnetized permanent magnet 254 is a strong magnet, if the magnet is magnetized before the permanent magnet 254 is fixed to the rotor 250, a strong attractive force between the rotor core 252 and the permanent magnet 254 is fixed. Occurs and hinders assembly work. In addition, due to the strong attractive force of the permanent magnet 254, dust such as iron powder may adhere to the permanent magnet 254. Therefore, when considering the productivity of the rotating electrical machine, it is preferable that the permanent magnet 254 is magnetized after being inserted into the rotor core 252.

  The permanent magnet 254 may be a neodymium-based or samarium-based sintered magnet, a ferrite magnet, a neodymium-based bonded magnet, or the like. The residual magnetic flux density of the permanent magnet 254 is about 0.4 to 1.4T.

  When a rotating magnetic field is generated in the stator 230 by flowing a three-phase alternating current through the stator winding 238, the rotating magnetic field acts on the permanent magnets 254a and 254b of the rotor 250 to generate torque. This torque is represented by the product of the component interlinked with each phase winding of the magnetic flux generated from the permanent magnet 254 and the component orthogonal to the interlinkage magnetic flux of the alternating current flowing through each phase winding. Here, since the alternating current is controlled to be sinusoidal, the product of the fundamental wave component of the interlinkage magnetic flux and the fundamental wave component of the alternating current becomes the time-average component of the torque, and the harmonic component of the interlinkage magnetic flux The product of the fundamental wave components of the alternating current becomes the torque ripple that is the harmonic component of the torque. That is, in order to reduce the torque ripple, the harmonic component of the flux linkage may be reduced. In other words, since the product of the interlinkage magnetic flux and the angular velocity at which the rotor rotates is the induced voltage, reducing the harmonic component of the interlinkage magnetic flux is equivalent to reducing the harmonic component of the induced voltage.

  FIG. 3 is a perspective view of the stator 230. In this embodiment, the stator winding 238 is wound around the stator core 232 by wave winding. Coil ends 241 of the stator winding 238 are formed on both end surfaces of the stator core 232. Further, a lead wire 242 of the stator winding 238 is drawn out on one end face side of the stator core 232. The lead wire 242 is drawn out corresponding to each of the U phase, the V phase, and the W phase.

  FIG. 4 is a connection diagram of the stator winding 238, showing the connection method and the electrical phase relationship of each phase winding. The stator winding 238 of this embodiment employs a double star connection, and includes a first star connection composed of a U1-phase winding group, a V1-phase winding group, and a W1-phase winding group, and a U2-phase winding. A second star connection composed of a group, a V2-phase winding group, and a W2-phase winding group is connected in parallel. The U1, V1, and W1 phase winding groups and the U2, V2, and W2 phase winding groups are each configured by four windings. The U1 phase winding group includes the windings U11 to U14, and the V1 phase. The winding group has circumferential windings V11 to V14, the W1 phase winding group has circumferential windings W11 to W14, the U2 phase winding group has circumferential windings U21 to U24, and the V2 phase windings The group has the windings V21 to V24, and the W2-phase winding group has the windings W21 to W24. In the first star connection and the second star connection, the U phases, the V phases, and the W phases are electrically connected to each other, and the connection portion is connected to the current sensor 660.

  The V phase and the W phase have substantially the same configuration as the U phase, and are arranged so that the phase of the voltage induced in each phase is shifted by 120 degrees in electrical angle. In addition, the angles of the respective windings represent relative phases. In this embodiment, the stator winding 238 employs a double star (2Y) connection connected in parallel. However, depending on the driving voltage of the rotating electrical machine, they may be connected in series to form a single star (1Y) connection. good.

  5 and 6 are diagrams showing the detailed connection of the U-phase winding of the stator winding 238. FIG. As described above, the stator core 232 is formed with 48 slots 237 (see FIG. 4), and reference numerals 1, 2,..., 47, 48 shown in FIG.

  FIG. 5A shows the windings U11 and U12 of the U1-phase winding group. FIG. 5B shows the windings U13 and U14 of the U1-phase winding group. FIG. 5C shows the windings U21 and U22 of the U2-phase winding group. FIG. 5D shows the windings U23 and U24 of the U2-phase winding group. FIG. 6 is a diagram showing the arrangement of the slot conductors, and shows the arrangement in the slot focusing only on the U-phase winding in the lower part of the figure.

  The stator winding group U1 is composed of the windings U11, U12, U13, and U14, and a voltage obtained by synthesizing the respective phases is induced in the U1-phase winding group. Similarly, in the case of the U2-phase winding group, a voltage in which the phases of the windings U21, U22, U23, and U24 are combined is induced. The U1-phase winding group and the U2-phase winding group are connected in parallel, but there is no phase difference between the voltages induced in the stator winding groups U1, U2, and they are connected in parallel. However, imbalances such as circulating current will not occur. Of course, it may be connected in series.

  Each of the windings U11 to U24 includes a slot conductor 233a inserted into the slot and a cross conductor 233b constituting the coil end 241 by connecting the same side ends of the slot conductor 233a inserted into different slots. Consists of. For example, in the case of the slot conductor 233a inserted through the slot 237 having the slot number 5 shown in FIG. 5A, the upper end in the figure is formed into the slot 237 having the slot number 48 by the crossing conductor 233b constituting the upper coil end. The lower end is connected to the upper end of the slot conductor 233a to be inserted, and conversely, the lower end is below the slot conductor 233a to be inserted into the slot 237 of the slot number 12 by the transition conductor 233b constituting the lower coil end. Connected to the side edge. In this manner, the slot conductor 233a is connected by the crossing conductor 233b, whereby a wave winding is formed.

  In this embodiment, four slot conductors 233a are inserted in one slot side by side from the inner circumference side to the outer circumference side, and are called layer 1, layer 2, layer 3, and layer 4 in order from the inner circumference side. In FIG. 5, the solid line portions of the windings U <b> 11, U <b> 12, U <b> 21, and U <b> 22 indicate layer 1, and the broken line portion indicates layer 2. In the circular windings U13, U14, U23, and U24, the alternate long and short dash line portion indicates the layer 3, and the dotted line portion indicates the layer 4.

  The circular windings U11 to U24 may be formed of a continuous conductor, or the segment coils may be connected to each other by welding after the segment coils are inserted into the slots. When the segment coil is used, before inserting the segment coil into the slot 237, the coil ends 241 positioned at both ends in the axial direction from the end of the stator core 232 can be formed in advance. The insulation distance can be easily provided and is effective for insulation.

  In addition, the conductor used for the circular winding may be a flat wire, a round wire, or a conductor with multiple thin wires, but in order to increase the space factor for the purpose of miniaturization and high output, Line is suitable.

  As shown in FIG. 5, the stator winding group U1 enters the layer 1 of the slot number 14 from the lead wire and straddles the six slots by the crossing conductors 233b, and then the slot conductor 233a becomes the layer 2 of the slot number 20. enter. Next, layer 2 of slot number 32 is entered from layer 1 of slot number 26 across six slots.

  In this way, the stator winding is wound by wave winding so that the stator core 232 goes around once to the layer 2 of slot number 8. The stator winding for approximately one turn so far is the circular winding U11 shown in FIG.

  Next, the stator winding (circular winding U11 in FIG. 6) exiting from layer 2 of slot number 8 enters layer 1 of slot number 13 across five slots. From the layer 1 of the slot number 13, the circular winding U12 shown in FIG. The circumferential winding U12 is also wound by wave winding as in the case of the circumferential winding U11.

  Note that the circumferential winding U12 is wound around the circumferential winding U11 with a shift of one slot pitch, so that a phase difference corresponding to an electrical angle corresponding to one slot pitch is generated. In the present embodiment, one slot pitch corresponds to an electrical angle of 30 degrees, and in FIG. 6 as well, the circumferential winding U11 and the circumferential winding U12 are described as being shifted by 30 degrees.

  Further, as shown in FIG. 5, the stator winding (circular winding U12 in FIG. 6) exiting from layer 2 of slot number 7 enters layer 3 of slot number 13 with a jumper wire straddling six slots. . From layer 3 of slot number 13, the winding turns to U13. The winding U13 is wound up to the layer 4 of the slot number 7, and then crosses 6 slots by the deformed crossing conductor 233c connecting the slot conductors of the same layer, and enters the layer 4 of the slot number 2. From layer 4 of slot number 2, it becomes a circular winding U14. Next, the stator winding coming out of layer 4 of slot number 2 enters layer 3 of slot number 44. Therefore, the circumferential winding U14 has a winding direction opposite to that of the circumferential windings U11 to U13. However, the direction of the current in each slot conductor is the same direction in the in-phase coil group described later.

  Note that the circumferential winding U14 is wound around the circumferential winding U13 with a shift of one slot pitch, so that a phase difference corresponding to an electrical angle corresponding to one slot pitch is generated. In the present embodiment, one slot pitch corresponds to an electrical angle of 30 degrees, and in FIG. 6 as well, the circumferential winding U13 and the circumferential winding U14 are described as being shifted by 30 degrees.

  Slot numbers are shifted one by one with respect to the circumferential windings U21 and U22 and the circumferential windings U13 and U14 and the circumferential windings U23 and U24 and the circumferential windings U11 and U12, and the layers 1, 2 and 3 and 4 are replaced. It has become a relationship. For this reason, as shown in FIG. 5, it is possible to achieve a positional relationship in which the deformed crossing conductor 233 c that connects the slot conductors in the same layer, the lead wire, and the jumper wire do not easily interfere with each other and can be easily connected to a terminal.

  FIG. 6 is a view mainly showing the arrangement of the slot conductors 233a in the stator core 232, and shows slot numbers 48 to 13 in FIG. The rotation direction of the rotor is from the left to the right in the figure. In the present embodiment, twelve slots 237 are arranged for two poles, that is, an electrical angle of 360 degrees. For example, slot numbers 01 to 12 correspond to two poles. Therefore, the number N of slots per pole is 6, and the number NSPP of poles per phase is 2 (= 6/3). In each slot 237, four slot conductors 233a of the stator winding 238 are inserted.

  Each slot conductor 233a is indicated by a rectangle, and in the rectangle, signs U, V, W indicating U phase, V phase, W phase and a direction from the side where the lead wire is located to the opposite side are shown. A cross mark “×” is shown, and a black circle mark “●” showing the opposite direction is shown.

  The slot conductor 233a on the innermost peripheral side (slot opening side) of the slot 237 is referred to as layer 1, and is referred to as layer 2, layer 3, and layer 4 in order from the outer peripheral side (slot bottom side). Reference numerals 01 to 12 are slot numbers similar to those shown in FIG.

  In addition, a diagram illustrating the arrangement relationship of the U-phase windings U11 to U24 is extracted and illustrated. Only the U-phase slot conductor 233a is indicated by reference numerals U11 to U24 representing the circular winding, and the V-phase and W-phase slot conductors 233a are indicated by reference signs V and W indicating the phases.

  In FIG. 6, the eight slot conductors 233a surrounded by broken lines are a slot conductor group 234 composed of U-phase slot conductors 233a. For example, the U-phase two-pole slot conductor group 234 in the figure includes slot conductors 233a of the windings U11, U12, U21, U22 disposed in the layers 1 and 2 of the slot numbers 48, 1, and 2. , Slot conductors 233a of the circumferential windings U13, U14, U23, and U24 disposed in the layers 3 and 4 of the slot numbers 1, 2, and 3, respectively.

  In general, when the number N of slots per pole is 6, the number of slots NSPP per pole is 2, and the number of layers of the slot conductor 233a in the slot 237 is 4, the U phase (V phase, W phase as shown in FIG. 7). In the same manner, a configuration in which the slot conductor 233a is also used is often employed. In this case, the windings of the same phase are arranged without shifting in the circumferential direction of the stator core 232.

  On the other hand, the configuration of the present embodiment is configured such that in-phase coils of the number of slots per phase per pole + 1 are arranged in the layer of the slot group in which the coils of the same phase are inserted. Therefore, coils of the same phase can be arranged in wider slots in the circumferential direction than in the conventional configuration, and the magnetomotive force generated by the current flowing through the conductor can be distributed. As a result, torque pulsation of the rotating electrical machine can be reduced.

  FIG. 8 shows a comparison of the torque waveform when an alternating current is applied to the rotating electrical machine of the present embodiment and the conventional rotating electrical machine configured as a full-winding winding and a short-winding winding as a conventional configuration. is there. As shown in the analysis result of FIG. 8, it can be seen that torque pulsation is reduced as compared with full-pitch winding and short-pitch winding, and an average torque larger than that of short-pitch winding is obtained.

  In the conventional configuration, either the full-pitch winding that can obtain a large average torque or the short-pitch winding that allows the reduction of the average torque to reduce pulsation has to be selected. It is possible to provide a rotating electrical machine in which the average torque is increased as compared with the short-pitch winding and the pulsation is further reduced.

  Modifications of the present embodiment are shown in FIGS. The arrangement of slot conductor groups, which is a modified example of the present embodiment, is shown when the number of slots per phase is 2 and the number of layers is 4. The arrangement of slot conductors in which current flows in the same phase and in the same direction is shown, and corresponds to the arrangement of slot conductor groups marked with “●” when attention is paid to a certain phase in FIG. That is, when the slot conductor arrangement is illustrated by taking FIG. 9A as an example of a modification, the slot conductors are arranged as shown in FIG. Regarding the arrangement of the slot conductors, the arrangement of the layers 3 and 4 can be interchanged as shown in FIGS. 9B and 9D. Further, as shown in FIGS. 9D and 9F, the arrangement of the slot conductor groups of layers 1 and 2 and the slot conductor groups of layers 3 and 4 may be interchanged.

  The relative arrangement of the inter-layer and slot conductor groups is not limited to that shown in the figure, and the basic configuration of M × N slot conductor groups is different from the configuration in which the number of slots per phase is N and the number of layers is 2M. It may be configured as described.

  11A to 11G exemplify the arrangement of slot conductor groups when the present invention is applied to a rotating electrical machine having 2 slots per phase and 6 layers per pole. The arrangement of slot conductors in which current flows in the same phase and in the same direction is shown, and corresponds to the arrangement of slot conductor groups marked with “●” when attention is paid to a certain phase in FIG. In each layer, the number of slots per phase per pole + 1, that is, three in-phase coils are arranged. FIG. 11A shows a slot conductor arrangement for two poles as an example of the modified example. The slot conductors are arranged as shown in FIG.

  Regarding the arrangement of the slot conductors, the arrangement of layers 3 and 4 and layers 5 and 6 can be interchanged as shown in FIGS. 11 (a) and 11 (c). Further, as shown in FIGS. 11B and 11G, the arrangement of the slot conductor groups of layers 1 and 2 and the slot conductor groups of layers 3 and 4 may be interchanged.

  The relative arrangement of the inter-layer and slot conductor groups is not limited to that shown in the figure, and the basic configuration of M × N slot conductor groups is different from the configuration in which the number of slots per phase is N and the number of layers is 2M. It may be configured as described.

  The configuration of the present embodiment is configured such that in-phase coils of the number of slots per phase per pole + 1 are arranged in the layer of the slot group in which the coils of the same phase are inserted. Therefore, coils of the same phase can be arranged in wider slots in the circumferential direction than in the conventional configuration, and the magnetomotive force generated by the current flowing through the conductor can be distributed. As a result, torque pulsation of the rotating electrical machine can be reduced.

  FIGS. 13A to 13E show the arrangement of slot conductor groups when the present invention is applied to a rotating electrical machine having 3 slots and 4 layers per pole per phase. The arrangement of slot conductors in which current flows in the same phase and in the same direction is shown, and corresponds to the arrangement of slot conductor groups marked with “●” when attention is paid to a certain phase in FIG. FIGS. 13A to 13C are examples in which the number of slots per phase per pole + 1, that is, four in-phase coils are arranged in each layer. FIGS. This is an example in which the number of slots per phase per pole + 2, that is, five in-phase coils are arranged. FIG. 13 (a) shows a slot conductor arrangement for two poles as an example, and the slot conductors are arranged as shown in FIG.

  Regarding the arrangement of the slot conductors, the arrangement of the layers 1 and 2 or the layers 3 and 4 may be interchanged with respect to the arrangement of the slot conductors. Further, the arrangement of the slot conductor groups of layers 1 and 2 and the slot conductor groups of layers 3 and 4 may be interchanged.

  The relative arrangement of the inter-layer and slot conductor groups is not limited to that shown in the figure, and the basic configuration of M × N slot conductor groups is different from the configuration in which the number of slots per phase is N and the number of layers is 2M. It may be configured as described.

  The configuration of the present embodiment is configured such that in-phase coils of the number of slots per phase per pole + 1 are arranged in the layer of the slot group in which the coils of the same phase are inserted. Therefore, coils of the same phase can be arranged in wider slots in the circumferential direction than in the conventional configuration, and the magnetomotive force generated by the current flowing through the conductor can be distributed. As a result, torque pulsation of the rotating electrical machine can be reduced.

200: Rotating electric machine 212: Housing 214: End bracket 216: Bearing 218: Shaft 222: Gap 224: Resolver 226: Address plate 230: Stator 232: Stator core 233a: Slot conductor 233b: Transition conductor 233c: Deformed transition conductor 234 : Slot conductor group 236: Teeth 237: Slot 238: Stator winding 241: Coil end 242: Lead wire 250: Rotor 252: Rotor core 253: Hole 254: Permanent magnet 257: Hole space

U11-U16, U21-U26, V11-V16, V21-V26, W11-W16, W21-W26: Circumferential winding

Claims (7)

A stator of a rotating electrical machine comprising a stator core having a plurality of slots, and a coil inserted through the slot,
In a predetermined layer of a slot group through which coils of the same phase are inserted, when N is an integer of 1 or more, the stator of the rotating electrical machine in which the number of slots per phase per pole + N in-phase coils are arranged A stator of a rotating electrical machine comprising a stator core having a plurality of slots, and a coil inserted through the slot,
A stator of a rotating electrical machine in which, in a predetermined layer of a slot group through which coils of in-phase are inserted, N is an integer equal to or greater than 1, and the number of slots per phase per pole-N in-phase coils are arranged. In the stator of the rotating electrical machine according to claim 1 or 2,
The N is a stator of a rotating electric machine that is an integer smaller than the number of slots per phase per pole. In the stator of the rotating electrical machine according to any one of claims 1 to 3,
The slot group has 2 × M layers when M is an integer greater than or equal to 1 and is arranged over M × (number of slots per phase + N) or less. The stator of the rotating electrical machine. In the stator of the rotating electrical machine according to any one of claims 1 to 4,
A stator for a rotating electrical machine, wherein the coil is composed of a rectangular wire.
Rotating electric machine. In the stator of the rotating electrical machine according to any one of claims 1 to 5,
A stator of a rotating electrical machine in which the coil is composed of segment windings constituting one turn. A stator for a rotating electrical machine according to any one of claims 1 to 6,
A rotating electrical machine including a rotor instructed to be rotatable with respect to the stator core via a gap.

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