JPH09135546A - Abduction-type rotary machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size and weight of a rotary machine by allowing a power supply frequency at the maximum number of rotations out of the numbers of rotations which give the maximum torque when a car is running at a low speed, the maximum phase voltage of the rotary machine at a high speed, the number of turns of a single-phase stator winding, and the length and width of a multilayer rotor iron core to satisfy a specified relation. SOLUTION: A stator 2 consists of a stator iron core 4 with a stator winding 5 and a stator supporting plate 6 which supports the stator iron core 4. A rotor 3 consists of a solid-state rotor iron core 7 and a multilayer rotor iron core formed on the inner surface of the iron core 7. When a power supply frequency at the maximum number of rotations out of the numbers of rotations which give the maximum torque when a car is running at a low speed is Fm(Hz), the maximum phase voltage of a rotary machine when the car is running at a high speed is Vb(V), the number of turns of a single-phase stator winding 5 is W, the length and width of the multilayer rotor iron core 7 are We(cm) and Hc(cm) respectively, Fm, Vb, W, We, and Hc should satisfy a specified relation shown by the formula. By this method, the size and weight of an abduction-type rotary machine 1 can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outer rotation type rotary electric machine, and particularly to a small and lightweight outer rotation type rotary electric machine and an electric vehicle equipped with the same.

[0002]

2. Description of the Related Art It is desired that an electric motor used for an electric vehicle such as an electric vehicle is small and lightweight. On the other hand, as a method of driving an electric vehicle, there is a method of disposing rotating machines in each driving wheel. This distributed arrangement method has various advantages such that the wheels can be directly driven, the gears are not required, and the efficiency is high, and the four wheels can be independently controlled to allow turning on the spot. . In this case, an outer rotor type rotary electric machine is optimal as a motor because of its structure. In the case of using this outer rotation type rotary electric machine, since the inertia is large when accelerating, it is required to make the rotary electric machine smaller and lighter.

In the conventional outer rotation type rotary electric machine, a system has been adopted in which the outer peripheral thickness of the laminated rotor core is sufficiently made to minimize magnetic saturation.

[0004]

This is because the conventional outer rotation type rotary electric machine is used for household rotary electric machines and the like.
This is because it is always used at a constant voltage and frequency, and if the magnetic saturation of the outer circumference of the laminated rotor core is extremely taken, the characteristics of the rotating electric machine will be significantly deteriorated.

The rotary electric machine of the present invention is intended for use as a drive motor for electric vehicles or electric locomotives, for example. In these electric motors, the electric motor is operated by a control device at a variable frequency and a variable voltage, and particularly in a region where a constant large torque is generated in a low rotation speed region and a region where a constant output is required at a high speed. When it is operated and in a steady state, it operates in the area inside. Only a few uphill and acceleration periods produce maximum flux and operate in maximum torque range. Therefore, if the magnetic flux density is made sufficiently low for this small period, the physical size of the rotating electric machine cannot be made sufficiently small, and there is a drawback that the size and weight cannot be reduced.

An object of the present invention is to provide a compact and lightweight outer rotation type electric rotating machine and an electric vehicle equipped with the same, excluding the drawbacks of the conventional example described above.

[0007]

The feature of the present invention for achieving the above-mentioned object is that the control operation is performed by changing the voltage with a substantially constant torque in the maximum torque region at low speed,
A rotating electric machine that is controlled and operated at a constant output at a high output at a high speed, and has a stator core with a stator winding wound around the inner circumference, and a gap around the stator. In the outer rotation type rotating electric machine having a rotor having a rotor core made of a solid rotor core,
The power supply frequency at the maximum rotation speed Nb (rpm) that gives the maximum torque at low speed is Fm (Hz), the maximum phase voltage of the rotating electric machine at high speed is Vb (V), and the one-phase stator winding Is W, and the axial length and width of the laminated rotor core are Wc (cm) and Hc (cm), respectively,

An outer rotation type electric rotating machine is characterized by being configured so as to satisfy the following relationship.

[0009]

Embodiments of the present invention will be described below.

FIG. 1 shows the structure of the outer rotation type electric rotating machine of the present invention.
The cross section is shown in FIG. In this embodiment, an induction motor will be described.

In FIGS. 1 and 2, an outer rotor type electric rotating machine 1 comprises a stator 2 and a rotor 3 which rotates around the outer periphery of the stator 2. Here, the stator 2 is composed of a stator core 4 having a stator winding 5 and a stator support plate 6 supporting the stator core 4.
The rotor 3 has a solid rotor core 7 and a laminated rotor core 8 on the inner periphery thereof, and the laminated rotor core 8 is provided with a slot 83 in which a bar 9 of the rotor winding is provided. It is equipped. An end ring 1 is attached to the shaft end of the rotor winding bar 9.
0, the rotor winding bars 9 are short-circuited to form a cage winding. The solid rotor iron core 7 is mounted on a shaft 11 as shown in the figure in a divided or integrated structure, and is rotatably supported by a stator support plate 6 via a bearing 12. Further, the stator support plate 6 is fixed and held by the rotary electric machine support plate 13. Here, the stator core 4 is composed of a tooth portion 41 and a core portion 42, and a slot portion 43 of a space formed by the tooth portion 41 and the core portion 42.
The stator winding 5 is inserted into the slot portion 43. Here, the winding configuration of the stator core 4 is the same as the winding configuration of a general three-phase electric motor.

FIG. 3 shows the operating characteristics of the outer rotation type rotary electric machine.

As a drive device for an electric vehicle such as an electric vehicle or an electric locomotive, the operating range of maximum torque is a control device for a rotating electric machine during a period requiring a constant large torque at a low speed and at a high speed. In order to reduce the capacity of the motor, there is a section where constant output control is performed, that is, control with the same torque characteristics as the series-wound motor. In this case, in the maximum torque range in the low speed region, control is performed to linearly change the voltage up to the base rotation speed as shown in the figure. Therefore, in this region, the maximum amount of magnetic flux of the electric motor is controlled to be kept substantially constant. The operation with the maximum torque is used for a short time such as when climbing a slope or when accelerating rapidly. In the case of traveling on a flat ground, it is generally operated in a region where the required torque is small in this region, and the region where the amount of magnetic flux is also small is generally operated. There, the choice of operation that maximizes efficiency is made. That is, the optimum amount of magnetic flux is selected and the control is continued. When the rotation speed of the rotating electric machine becomes higher than the base rotation speed, the torque is controlled so as to decrease with the rotation speed in inverse proportion to the rotation speed as shown in the figure, so that a constant output curve is obtained. The magnetic flux is controlled according to the torque, that is, field weakening control is performed. Even at high speeds, in the case of traveling on level ground, it is generally operated in a region where the required torque is small in this region, and the amount of magnetic flux is also generally operated in a region where it is smaller. Here too, the choice of operation is made to maximize efficiency. That is, the optimum amount of magnetic flux is selected and the control is continued.

In the maximum torque range at low speed, the power supply frequency Fm at the base rotation speed Nb is given by (Equation 1).

[0015]

## EQU00001 ## Fm = Nb.P ./ (1-s) / 120 (Equation 1) where P is the number of poles of the motor, and s is the slip.

From the above power supply frequency, the magnetic flux amount Φm in the maximum torque region at low speed can be calculated by (Equation 2).

[0017]

(Equation 2)

Here, Fm (Hz) is the power supply frequency at that time, Vb (V) is the maximum phase voltage of the rotating electric machine at high speed, and W is the number of turns of the stator winding of one phase.

From the above formula for calculating the magnetic flux, the magnetic flux density of the laminated rotor core of the rotary electric machine can be calculated by (Equation 3).

[0020]

(Equation 3)

Here, Wc (cm) is the axial length of the laminated rotor core, and Hc (cm) is the width of the core portion of the laminated rotor core.

The maximum of the magnetic flux density in the laminated rotor core is generally limited by the maximum value of the magnetic flux density of the silicon steel sheet used for it, and is about 21 kG. In the value calculated by the above formula, the maximum magnetic flux density in the laminated rotor core is set to 25 kG, which is larger than about 21 kG, so that the saturation of the laminated rotor core can be increased and the machine can be made compact and lightweight. . Actually, the magnetic flux density in the laminated rotor core is 25
It does not become kG, and it flows toward the solid rotor core. Eddy currents are generated here when the magnetic flux flows in the solid rotor core, but the operation used here is only a short time for climbing and acceleration, and the magnetic flux in the rotor has only a slight slip frequency. Since the eddy current is extremely small, the characteristics are not greatly impaired. By constructing the solid rotor core, which is a strength member, positively used in the magnetic circuit, the physical size of the rotating electric machine can be significantly reduced. As a result, it is possible to correct the drawback of the outer rotation type rotary electric machine that the rotary inertia is large.

This is a big difference from the commonly used adder-type rotary electric machine. In the case of an adder-type rotary electric machine, the outer circumference of the rotor is almost determined by the capacity of the electric motor,
Therefore, the magnetic flux density of the laminated rotor core does not become large. Even if the magnetic flux density of the laminated rotor is increased, the physical size of the rotating electric machine cannot be reduced due to its structure. On the other hand, in the outer rotating electric machine, the magnetic flux density of the laminated rotor core immediately leads to a reduction in size and weight. Particularly, since the inertia of the rotor is proportional to the fourth power of the outer circumference of the rotor, its influence is very large.

FIG. 4 shows another embodiment of the present invention.

1 to 3 show examples of induction motors.
In this embodiment, an example in which the present invention is applied to a reluctance type rotary electric machine will be described. In the figure, the configuration of the stator 2 is the same as the configuration of the outer rotation type rotary electric machine of the induction motor shown in FIG. The rotor 3 is a solid rotor core 7 and a laminated rotor core 8
It is composed of The laminated rotor core 8 is configured to have four magnetic poles on a protrusion in the circumferential direction as shown in the figure. The space between the magnetic poles generated in the rotor can be filled with a resin and a non-magnetic insulator as needed. Here, the magnetic flux density of the core portion composed of the laminated rotor core 8 is exactly the same in the reluctance motor under the operating conditions shown in FIG. 3, and thus can be expressed in the same manner as (Equation 3). Therefore, by setting the magnetic flux density of the core portion composed of the laminated rotor core to 25 kG or more, the same effect as in the case of the induction motor can be obtained.

In the outer rotation type rotating electric machine having the above structure, the outer peripheral portion is formed of the solid rotating yoke, so that the mechanical strength is increased and it is not necessary to increase the outer diameter of the rotor. it can. Although an example of using a non-salient stator as the stator has been described above, it is also effective when a salient pole-shaped stator is used. Further, in the operation shown in FIG. 3, an example in which the voltage is controlled so as to increase linearly with respect to the rotation speed has been shown, but it is also effective when increasing with respect to the rotation speed in a polygonal or parabolic shape. In this case, the point where the magnetic flux density exceeds 25 kG at the point where Vb / Fm from the origin is maximum in the region close to the base rotation speed is defined.

[0027]

According to the present invention, it is possible to provide a small and light outer rotation type electric rotating machine and an electric vehicle equipped with the same.

[Brief description of the drawings]

FIG. 1 shows a structural diagram of an outer rotation type rotary electric machine of the present invention.

FIG. 2 shows a cross-sectional view of an outer rotation type rotary electric machine of the present invention.

FIG. 3 shows characteristics of the outer rotation type rotary electric machine of the present invention.

FIG. 4 shows another embodiment of the outer rotation type rotary electric machine of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Outer rotary electric machine, 2 ... Stator, 3 ... Rotor, 4 ... Stator core, 5 ... Stator winding, 6 ... Stator support plate, 7 ... Solid rotor core, 8 ... Laminated rotor Iron core, 9 ... Rotor winding bar, 10 ... End ring, 11 ... Shaft, 12 ... Bearing, 13 ... Rotating electric machine support plate, 41 ... Tooth portion, 42 ...
Core portion, 43 ... Slot portion, 81 ... Teeth portion of laminated rotor core, 82 ... Core portion of laminated rotor core, 83 ... Slot portion of laminated rotor core.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Suetaro Shibukawa 2520 Takaba, Hitachinaka City, Ibaraki Prefecture Hitachi Ltd. Automotive Equipment Division (72) Inventor Seikichi Masuda 3-1-1, Saiwaicho, Hitachi City, Ibaraki Prefecture No. Stock Company Hitachi Ltd.Hitachi factory

Claims (4)

[Claims] 1. A rotating electric machine which is controlled and operated by changing a voltage with a substantially constant torque in a maximum torque region at a low speed, and is controlled and operated at a substantially constant output at a high speed and with a substantially constant voltage, and An outer rotation type having a stator having a stator core having a stator winding wound around the inner periphery thereof, and a rotor having a rotor core made of solid rotor core solid on the outer periphery of the rotor core. In the rotating electric machine, the power source frequency at the maximum rotating speed Nb (rpm) among the rotating speeds that gives the maximum torque at low speed is Fm (Hz), the maximum phase voltage of the rotating electric machine at high speed is Vb (V), When the number of turns of the stator winding is W and the axial length and width of the laminated rotor core are Wc (cm) and Hc (cm), respectively, An outer rotation type electric rotating machine configured to satisfy the following relationship. 2. The outer rotation type electric rotating machine according to claim 1, wherein the rotation type induction motor is an induction motor having a cage type rotor as the rotor. 3. The outer rotating electric machine according to claim 1, wherein the rotor is a reluctance electric motor having a reluctance iron core as the rotor. 4. An electric vehicle comprising the outer rotation type electric rotating machine according to claim 1.