JP2016010270A - Rotary electric machine and control device for rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine capable of improving mountability.SOLUTION: A motor 3 includes: a rotor 30 including magnetic poles; and a stator 40 which is disposed in an outer periphery of the rotor 30. The stator 40 includes: a stator core 41 in which a plurality of teeth 44a-44l are formed at angle intervals equal to a mechanical angle of 24°; and phase coils 42u-42w wound around the teeth 44a-44l. The stator core 41 is formed from: a first core part 41a including the six teeth 44a-44f; and a second core part 41b including the six teeth 44g-44l. The first core part 41a and the second core part 41b are disposed oppositely to each other while holding the rotor 30 therebetween. A winding direction of the phase coils 42u-42w in the first core part 41a is reverse to a winding direction of the phase coils 42u-42w in the second core part 41b.

Description

  The present invention relates to a rotating electrical machine such as a motor and a generator, and a control device for the rotating electrical machine.

  In recent years, hybrid vehicles having two power sources of an engine and a motor have become widespread. As one of this type of hybrid vehicle, a motor-assisted four-wheel drive vehicle in which one of the front wheels and the rear wheels of the vehicle is driven to rotate by an engine and the other of the front wheels and rear wheels is driven to rotate by a motor. Is known (see, for example, Patent Document 1). The vehicle includes a generator that generates power using engine power and a secondary battery that stores electric power generated by the generator, and drives the motor with electric power stored in the secondary battery. For example, a three-phase brushless motor is used as the motor. The number of poles and the number of slots of the motor are appropriately set according to vehicle specifications.

JP 2013-9513 A

  By the way, when a motor as described above is mounted on a vehicle, it is necessary to secure a motor mounting space in the vehicle. However, it may be difficult to secure a motor mounting space in the vehicle due to space limitations of the vehicle.

In addition, such a subject is a subject common not only to the motor mounted in a vehicle but to rotary electric machines, such as a motor and a generator mounted in various apparatuses.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a rotating electrical machine capable of improving the mountability and a control device for the rotating electrical machine.

A rotating electrical machine that solves the above problems includes a rotor having magnetic poles and a stator that is disposed on the outer periphery of the rotor, and the stator has a plurality of teeth formed at equal angular intervals in the circumferential direction of the rotor. A stator core and each phase coil wound around the teeth, and when the angular interval between teeth adjacent to each other in the circumferential direction of the rotor is θ as a mechanical angle, n = 360 ° / θ
Is set to an odd number, and m is a natural number, the number T of the teeth is expressed by the following equation: T = n−3 × (2 × m−1)
T> 0
The stator core is composed of a first core portion and a second core portion each having T / 2 teeth, and the first core portion and the second core portion sandwich the rotor. The winding direction of each phase coil of the first core portion and the winding direction of each phase coil of the second core portion are set in opposite directions.

  In a conventional rotating electric machine, the stator core usually has an annular shape. When the stator core is in an annular shape, assuming that teeth are formed at a mechanical angle of θ on the stator core, the total number of teeth is “360 ° / θ”, that is, the value of n described above. Therefore, the rotating electrical machine in which the value of n is set to an odd number corresponds to the rotating electrical machine in which the number of slots is set to an odd number. Focusing on this point, since the number T of teeth is set to “n−3 × (2 × m−1)” in the above configuration, the number of teeth is “compared to the case where the stator core has an annular shape”. It is decreased by “3 × (2 × m−1)”. That is, the stator core has a shape having a notch in a part of the ring. Further, in the above configuration, the stator core is separated into the first core portion and the second core portion, and they are disposed to face each other with the rotor interposed therebetween, so that the stator core is located between the first core portion and the second core portion. It has a shape having a notch. Therefore, according to the said structure, compared with the case where a stator core makes an annular | circular shape, the dimension of the stator core in the direction orthogonal to the opposing direction of a 1st core part and a 2nd core part can be made small. Therefore, since the rotating electrical machine can be reduced in size, the mountability of the rotating electrical machine can be improved.

  Moreover, if the winding direction of each phase coil of a 1st core part and the winding direction of each phase coil of a 2nd core part are set to a reverse direction like the said structure, each phase of a 1st core part is set. A relative shift between the phase of the moving magnetic field formed by the coil and the phase of the moving magnetic field formed by each phase coil of the second core part can be eliminated. As a result, it is possible to ensure an operation according to a rotating electrical machine having n slots, that is, a rotating electrical machine having an odd number of slots.

  Instead of the method of setting the winding direction of each phase coil of the first core part and the winding direction of each phase coil of the second core part in opposite directions, each of the first core parts You may employ | adopt the method of providing a 180 degree phase difference between the electricity supply phase of a phase coil, and the electricity supply phase of each phase coil of the said 2nd core part. Even in this configuration, the relative deviation between the phase of the moving magnetic field formed by each phase coil of the first core part and the phase of the moving magnetic field formed by each phase coil of the second core part is eliminated. Can do.

  In the rotating electrical machine, the first core portion and the second core portion each have a first back yoke and a second back yoke that extend linearly in a direction orthogonal to the axial direction of the rotor, and the first core Each tooth of the portion is formed to protrude in parallel from the first back yoke toward the rotor, and each tooth of the second core portion protrudes in parallel from the second back yoke toward the rotor. It is preferable to form so as to.

  According to this configuration, the total length of the teeth can be increased while the dimension of the stator core in the direction orthogonal to the facing direction of the first core portion and the second core portion is shortened. Thereby, since the number of turns of each phase coil can be increased while reducing the size of the motor, the output of the rotating electrical machine can be improved.

  As a control device for a rotating electrical machine, the rotating electrical machine as described above, a first drive circuit for energizing each phase coil of the first core unit, and the first drive circuit are provided separately from the second core unit. And a second drive circuit for energizing each phase coil, and controlling the drive of the rotating electrical machine via the first drive circuit and the second drive circuit.

  According to this configuration, even when an abnormality occurs in one of the first drive circuit and the second drive circuit, the rotating electrical machine can be driven through the other drive circuit. That is, since the drive circuit can be made redundant, the reliability can be improved. In addition, since the energization phase of each phase coil of the first core part and the energization phase of each phase coil of the second core part can be set separately via the first drive circuit and the second drive circuit, A phase difference of 180 ° can be easily provided in the energization phase.

  According to the present invention, mountability can be improved.

The block diagram which shows schematic structure of a four-wheel drive vehicle of a rear-wheel motor assist type. Sectional drawing which shows the cross-sectional structure about one Embodiment of a motor. The block diagram which shows the structure of the control apparatus of the motor of embodiment. Sectional drawing which shows the cross-section of the conventional motor. The block diagram which shows the structure about the modification of the control apparatus of a motor. Sectional drawing which shows the cross-sectional structure about the modification of a motor. Regarding the modification of the motor, the angular interval θ of the teeth, the value n (= 360 ° / θ), the number of teeth in the first core portion, the number of teeth in the second core portion, the total number T of teeth, and the value “n−” The table | surface which shows the relationship of "T".

  Hereinafter, as an embodiment of a rotating electrical machine, a motor mounted on a rear-wheel motor-assisted four-wheel drive vehicle will be described as an example. First, an outline of a rear-wheel motor-assisted four-wheel drive vehicle will be described.

  As shown in FIG. 1, the vehicle 1 according to the present embodiment includes an engine 2 as a power source for driving front wheels and a motor 3 as a power source for driving rear wheels. The engine 2 is connected to left and right front wheels 5 via a drive shaft 4. Left and right rear wheels 9 are connected to the motor 3 via a speed reducer 6, a differential gear 7, and a drive shaft 8. That is, the front wheels 5 are rotationally driven by the power of the engine 2 and the rear wheels 9 are rotationally driven by the power of the motor 3. In addition, the vehicle 1 includes a generator 10 that generates power using the power of the engine 2, a secondary battery 11 that stores electric power generated by the generator 10, and a control device 12 that controls driving of the motor 3. ing. The control device 12 detects a vehicle state quantity such as an accelerator opening degree and a vehicle speed by a sensor 13 mounted on the vehicle 1, and supplies power from the secondary battery 11 to the motor 3 based on the detected vehicle state quantity. The motor 3 is driven. As a result, the rear wheels 9 are driven to rotate according to the traveling state of the vehicle, and a four-wheel drive traveling performance can be obtained.

Next, the structure of the motor 3 will be described. The motor 3 of this embodiment is a three-phase brushless motor.
As shown in FIG. 2, the motor 3 includes an output shaft 20 that is connected to the speed reducer 6 and rotates about the axis m, a rotor 30 that is integrally attached to the outer periphery of the output shaft 20, and an outer periphery of the rotor 30. And a stator 40 to be arranged. The outer periphery of the stator is surrounded by the housing 50. In the drawing, the direction indicated by the arrow CW and the direction indicated by the arrow CCW indicate the rotation directions of the output shaft 20 and the rotor 30.

  The rotor 30 includes a cylindrical rotor core 31 and a permanent magnet 32 embedded in the rotor core 31. That is, the motor 3 of this embodiment is an IPM motor (Interior Permanent Magnet Motor). The rotor core 31 is configured by laminating a plurality of electromagnetic steel plates in the axial direction. The output shaft 20 is fitted in the central hole 31 a of the rotor core 31. Ten rectangular magnet insertion holes 31b penetrating in the axial direction are formed on the outer edge of the rotor core 31 at equal angular intervals (specifically, 36 ° mechanical angles) in the circumferential direction. A permanent magnet 32 is inserted and fixed in each magnet insertion hole 31b. Each permanent magnet 32 has different magnetic poles on the inner and outer portions of the rotor core in the radial direction. In the rotor core 31, permanent magnets 32 having an N pole in the radially outer portion and permanent magnets 32 having an S pole in the radially outer portion are alternately arranged. Thereby, the rotor 30 has a 10-pole structure in which N poles and S poles are alternately arranged on the outer peripheral portion thereof.

  The stator 40 has a stator core 41 composed of a first core portion 41a and a second core portion 41b separated from each other, and phase coils 42u to 42w as moving magnetic field generating means.

  The first core portion 41a has an arc-shaped first back yoke 43a and six teeth 44a to 44f. The first back yoke 43a is divided for each of the teeth 44a to 44f. The teeth 44a to 44f are arranged at a mechanical angle of 24 ° in the rotor circumferential direction. Hereinafter, for the sake of convenience, among the six teeth 44a to 44f, the tooth 44a disposed at the end in the CW direction is referred to as a “first tooth” and the teeth sequentially disposed from the first tooth 44a to the CCW direction. 44b to 44f are sequentially referred to as “second to sixth teeth”. A U-phase coil 42u, a V-phase coil 42v, and a W-phase coil 42w are wound around the first to sixth teeth 44a to 44f in this order.

  Similarly to the first core portion 41a, the second core portion 41b also has an arc-shaped second back yoke 43b and six teeth 44g to 44l. Here, for convenience, among the six teeth 44g to 44l, the tooth 44g arranged at the end in the CW direction is referred to as “seventh tooth”, and the teeth arranged sequentially from the seventh tooth 44g in the CCW direction. 44h to 44l are sequentially referred to as “eighth to twelfth teeth”. A U-phase coil 42u, a V-phase coil 42v, and a W-phase coil 42w are wound around the seventh to twelfth teeth 44g to 44l in order. The winding directions of the phase coils 42u to 42w wound around the seventh to twelfth teeth 44g to 44l are the winding directions of the phase coils 42u to 42w wound around the first to sixth teeth 44a to 44f. And in the opposite direction.

  The first core portion 41 a and the second core portion 41 b are disposed to face each other with the rotor 30 interposed therebetween. Thereby, the mechanical angle between the first tooth 44a of the first core portion 41a and the twelfth tooth 44l of the second core portion 41b is shifted by 60 °. Further, the sixth tooth 44f of the first core portion 41a and the seventh tooth 44g of the second core portion 41b are also shifted by 60 ° in mechanical angle. The stator core 41 includes the first core portion 41a and the second core portion 41b, and has a shape having a notch between the first core portion 41a and the second core portion 41b.

  The housing 50 has an elliptical shape with a cross-section orthogonal to the rotor axial direction, and has two arc portions 51a and 51b and two linear portions 52a and 52b that connect the both end portions, respectively. ing. The first core portion 41a and the second core portion 41b are fixed to the inner peripheral surfaces of the arc portions 51a and 51b, respectively.

Next, the electrical configuration of the motor 3 and the control device 12 will be described.
As shown in FIG. 3, the control device 12 includes a drive circuit 60 that drives the motor 3 and an MPU (microprocessing unit) 61 that controls the drive of the motor 3 via the drive circuit 60. The drive circuit 60 has a known inverter circuit that converts a direct current supplied from a power source such as an in-vehicle battery into a three-phase (U-phase, V-phase, W-phase) alternating current. The MPU 61 generates a control signal Sc based on the vehicle state quantity detected by the sensor 13, and outputs this control signal Sc to the drive circuit 60. As a result, three-phase alternating currents Iu, Iv, and Iw corresponding to the control signal Sc are supplied from the drive circuit 60 to the phase coils 42u to 42w of the first core portion 41a and the second core portion 41b of the motor 3. The MPU 61 controls the driving of the motor 3 through such energization control.

  Next, the operation of the motor 3 of this embodiment will be described in comparison with the conventional motor 14 shown in FIG. In FIG. 4, the same elements as those illustrated in FIG. 2 are denoted by the same reference numerals, and redundant description is omitted.

  The motor 14 shown in FIG. 4 includes an annular stator core 70. The stator core 70 is formed with 15 teeth 71a to 71o at a mechanical angle of 24 °. That is, the motor 14 is an example of a motor in which the number of slots is set to an odd number. Hereinafter, for the sake of convenience, the teeth 71a are referred to as “first teeth”, and the teeth 71b to 71o arranged in this order from the first teeth 71a in the CCW direction are referred to as “second to fifteenth teeth”. A U-phase coil 42u, a V-phase coil 42v, and a W-phase coil 42w are wound around the first to fifteenth teeth 71a to 71o in this order.

  Here, the motor 3 of the present embodiment shown in FIG. 2 excludes the thirteenth to fifteenth teeth 71m to 71o from the conventional motor 14 shown in FIG. 4 and then the seventh to twelfth teeth 71g to 71l. Is shifted relative to the positions of the first to sixth teeth 71a to 71f in the CCW direction by a mechanical angle of 36 °.

  Incidentally, in the motor 14 shown in FIG. 4, if the positions of the seventh to twelfth teeth 71g to 71l are shifted by 36 degrees in mechanical angle, the respective phase coils 42u to 42w of the seventh to twelfth teeth 71g to 71l are used. The formed moving magnetic field will shift. Specifically, the moving magnetic field formed by the phase coils 42u to 42w of the seventh to twelfth teeth 71g to 71l is the moving magnetic field formed by the phase coils 42u to 42w of the first to sixth teeth 71a to 71f. On the other hand, the electrical angle is relatively shifted by 180 °.

  Therefore, in the motor 3 of the present embodiment shown in FIG. 2, the winding direction of the phase coils 42 u to 42 w of the second core portion 41 b is set with respect to the winding direction of the phase coils 42 u to 42 w of the first core portion 41 a. Are set in the opposite direction. Thereby, the relative between the phase of the moving magnetic field formed by the phase coils 42u to 42w of the first core part 41a and the phase of the moving magnetic field formed by the phase coils 42u to 42w of the second core part 41b. Can be eliminated. Therefore, in the motor 3 of this embodiment, the operation | movement according to the conventional motor 14 shown in FIG. 4 is realizable.

According to the motor 3 of the present embodiment described above, the following operations and effects can be obtained.
(1) In the motor 3 of the present embodiment, the stator core 41 has a notch between the first core portion 41a and the second core portion 41b. Therefore, as compared with the case where the annular stator core 70 as shown in FIG. 4 is used, the dimension of the stator core 41 in the direction (direction indicated by the arrow B) orthogonal to the facing direction of the first core portion 41a and the second core portion 41b. Can be reduced. Therefore, since the motor 3 of this embodiment becomes small compared with the conventional motor 14 shown in FIG. 4, mounting property can be improved. Thereby, the freedom degree of the mounting layout of the motor 3 to the vehicle 1 becomes high, and the floor of the vehicle can be reduced.

In addition, the said embodiment can also be implemented with the following forms.
-Instead of the method of setting the winding direction of each phase coil 42u-42w of the 1st core part 41a and the winding direction of each phase coil 42u-42w of the 2nd core part 41b to a reverse direction, it replaces with a 1st core. A method of providing a 180 ° phase difference between the energization phases of the phase coils 42u to 42w of the portion 41a and the energization phases of the phase coils 42u to 42w of the second core portion 41b may be employed. Specifically, as shown in FIG. 5, the control device 12 includes a first drive circuit 62 that energizes each phase coil 42 u to 42 w of the first core portion 41 a and each phase coil 42 u to 42 w of the second core portion 41 b. And a second drive circuit 63 for energizing each of them. In this modification, the winding direction of the phase coils 42u to 42w of the first core portion 41a and the winding direction of the phase coils 42u to 42w of the second core portion 41b are the same direction. The MPU 61 of the control device 12 is provided with a phase difference of 180 ° between the energization phase of the phase coils 42u to 42w of the first core portion 41a and the energization phase of the phase coils 42u to 42w of the second core portion 41b. Thus, the drive circuits 62 and 63 are driven. That is, assuming that the three-phase alternating currents supplied to the phase coils 42u to 42w of the first core portion 41a are "Iu", "Iv", and "Iw", respectively, the MPU 61 has a three-phase direction opposite to those. Currents “−Iu”, “−Iv”, and “−Iw” are supplied to the phase coils 42u to 42w of the second core portion 41b. Even in such a configuration, the phase of the moving magnetic field formed by each phase coil 42u to 42w of the first core portion 41a and the phase of the moving magnetic field formed by each phase coil 42u to 42w of the second core portion 41b. Since the relative shift between them can be eliminated, the effect according to the above embodiment can be obtained. Further, if the drive circuit is made redundant as shown in FIG. 5, even if any one of the first drive circuit 62 and the second drive circuit 63 is abnormal, the motor 3 is driven through the other drive circuit. Can do. Therefore, reliability can be improved. In the control device 12 shown in FIG. 3 as well, reliability can be improved by making the drive circuit redundant in the same manner.

  The shape of the first back yoke 43a and the second back yoke 43b is not limited to an arc shape. For example, as shown in FIG. 6, the first back yoke 43a and the second back yoke 43b may be formed linearly in a direction orthogonal to the rotor axial direction. In this case, the 1st-6th teeth 44a-44f of the 1st core part 41a are formed so that it may extend in parallel toward the rotor 30 from the 1st back yoke 43a. Similarly, the seventh to twelfth teeth 44g to 44l of the second core portion 41b are also formed to extend in parallel toward the rotor 30 from the second back yoke 43b. The housing 50 is formed in a rectangular shape. According to such a configuration, the total length of each of the teeth 44a to 44l can be increased while the dimension of the stator core 41 in the B direction is shortened. Thereby, since the number of turns of each phase coil 42u-42w can be increased, miniaturizing the motor 3 in the B direction, the output of the motor 3 can be improved.

  In the above embodiment, the first back yoke 43a and the second back yoke 43b are divided for each of the teeth 44a to 44l. However, the first back yoke 43a and the second back yoke 43b are divided for each of the teeth 44a to 44l. It may be a monolithic structure.

  The number of permanent magnets provided in the rotor 30 (number of poles) and the number of teeth provided in each of the first core portion 41a and the second core portion 41b (number of slots) can be appropriately changed as shown in FIG. 7, for example. It is. The tooth angle interval θ is a mechanical angle. The value n (= 360 ° / θ) represents the number of teeth when the stator core is a complete annular shape, that is, the number of teeth in the conventional motor. Furthermore, “n-T” can be reduced when the stator core separated into the first core portion and the second core portion as in the above embodiment is used as compared with the case where the conventional annular stator core is used. Represents the number of teeth. In short, it is sufficient that the stator is configured to satisfy the conditions shown in the following (a) to (e).

(A) When an angular interval between teeth adjacent to each other in the circumferential direction of the rotor is θ as a mechanical angle, a value n obtained by “n = 360 ° / θ” is an odd number.
(B) When m is a natural number, the number of teeth T (> 0) is set to satisfy “T = n−3 × (2 × m−1)”.

(C) The stator core is composed of a first core portion and a second core portion each having T / 2 teeth.
(D) The first core portion and the second core portion are disposed to face each other with the rotor interposed therebetween.

  (E) The winding direction of each phase coil of the first core part and the winding direction of each phase coil of the second core part are set in opposite directions. Alternatively, a phase difference of 180 ° is provided between the energization phase of each phase coil of the first core part and the energization phase of each phase coil of the second core part.

  In the above embodiment, an IPM motor is employed as the motor 3, but an SPM motor (Surface Permanent Magnet Motor) having a structure in which a permanent magnet is attached to the outer peripheral surface of the rotor may be employed.

The configuration of the above embodiment may be used for a four-wheel drive vehicle in which the rear wheels are engine-driven and the front wheels are motor-assisted.
-The motor 3 of the said embodiment is not restricted to a rear-wheel motor-assisted four-wheel drive vehicle, For example, you may use as a drive source of an electric power steering apparatus. Further, the motor of the above embodiment is not limited to a vehicle, and may be used as a rotating electrical machine for various purposes such as a drive source of various devices or a generator.

In the above embodiment, the magnetic pole is formed by using the permanent magnet 32, but the magnetic pole may be formed by a field winding.
(Appendix)
Next, a technical idea that can be grasped from the above embodiment and its modifications will be additionally described.

  (A) In a vehicle drive device in which either one of a front wheel and a rear wheel of a vehicle is rotationally driven by an engine and the other of the front wheels and the rear wheel is rotationally driven by a rotating electrical machine, A rotating electrical machine described in the item is used. According to this configuration, the rotating electrical machine can be easily mounted on the vehicle.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Engine, 3 ... Motor (rotary electric machine), 12 ... Control apparatus, 30 ... Rotor, 40 ... Stator, 41 ... Stator core, 41a ... 1st core part, 41b ... 2nd core part, 42u-42w ... each phase coil, 43a ... 1st back yoke, 43b ... 2nd back yoke, 44a-44l ... teeth, 62 ... 1st drive circuit, 63 ... 2nd drive circuit.

Claims (4)

A rotor having magnetic poles;
A stator disposed on the outer periphery of the rotor,
The stator is
A stator core having a plurality of teeth formed at equiangular intervals in the circumferential direction of the rotor;
Each phase coil wound around the teeth,
When the angular interval between the teeth adjacent to each other in the circumferential direction of the rotor is θ as a mechanical angle, the following formula n = 360 ° / θ
The value n determined by is set to an odd number,
When m is a natural number, the number T of the teeth is expressed by the following formula: T = n−3 × (2 × m−1)
T> 0
Set to meet
The stator core includes a first core portion and a second core portion each having T / 2 teeth,
The first core part and the second core part are arranged to face each other with the rotor interposed therebetween,
A rotating electrical machine in which a winding direction of each phase coil of the first core part and a winding direction of each phase coil of the second core part are set in opposite directions. A rotor having magnetic poles;
A stator disposed on the outer periphery of the rotor,
The stator is
A stator core having a plurality of teeth formed at equiangular intervals in the circumferential direction of the rotor;
Each phase coil wound around the teeth,
When the angular interval between the teeth adjacent to each other in the circumferential direction of the rotor is θ as a mechanical angle, the following formula n = 360 ° / θ
The value n determined by is set to an odd number,
When m is a natural number, the number T of the teeth is expressed by the following formula: T = n−3 × (2 × m−1)
T> 0
Set to meet
The stator core includes a first core portion and a second core portion each having T / 2 teeth,
The first core part and the second core part are arranged to face each other with the rotor interposed therebetween,
A rotating electrical machine in which a phase difference of 180 ° is provided between an energization phase of each phase coil of the first core portion and an energization phase of each phase coil of the second core portion. The first core portion and the second core portion each have a first back yoke and a second back yoke that extend linearly in a direction orthogonal to the axial direction of the rotor,
Each tooth of the first core portion is formed to protrude in parallel from the first back yoke toward the rotor,
The rotating electrical machine according to claim 1, wherein each tooth of the second core portion is formed so as to protrude in parallel from the second back yoke toward the rotor. The rotating electrical machine according to any one of claims 1 to 3,
A first drive circuit for energizing each phase coil of the first core part;
A second drive circuit provided separately from the first drive circuit and energizing each phase coil of the second core part,
A control device for a rotating electrical machine that controls driving of the rotating electrical machine via the first drive circuit and the second drive circuit.