JPH0775213A - Electric car and drive unit therefor - Google Patents

Abstract

PURPOSE:To provide a compact, light-weight, efficient, and safe electric car drive unit that can be charged through a household power supply by providing an electric motor stator with a special charging transformer and reactor. CONSTITUTION:An iron core 5 of an electric motor stator 2 comprises a core 5A, teeth 5B, and second core 5C used for a transformer and reactor. Electric winding 12A is laid in electric winding slots 13A in the iron core 5. In the external surface of the core 5A and internal surface of the second core 5C are provided transformer winding slots 13B and reactor winding slots 13C, which accommodate transformer winding 12B and reactor winding 12c, respectively. To avoid magnetic flux saturation, a gap 30 is provided in the iron core inside the reactor winding 12C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive unit for an electric vehicle incorporating a charging transformer and a reactor, and more particularly to an electric vehicle equipped with a small and lightweight drive unit for an electric vehicle.

[0002]

2. Description of the Related Art An electric vehicle typified by an electric vehicle is driven by battery power. The battery charging of this electric vehicle is inconvenient because it needs to be charged at a place where facilities such as a gas station are available. As a method for solving this problem, Japanese Patent Application Laid-Open No. 4-101602 discloses a method in which an electric vehicle is diverted so that it can be charged in a general household. According to this method, a plurality of windings are arranged on the inner circumference of a stator of a motor of an electric vehicle, electromagnetic induction between the windings acts as a transformer, and a battery is charged from an external power supply. In this system, the windings of the electric motor are used both for rotation and for the transformer.

[0003]

In the prior art, since the plurality of windings of the electric motor are used for both the rotation and the transformer, (1) there is a point that the abch is not removed. growing. (2) When acting as a transformer,
The air gap between the rotor and the stator on the magnetic circuit, and (3) in the case of a basket type induction motor, the eddy current generated in the rotor reduces the transformer efficiency. (4) The electric motor may be carelessly rotated. There is a problem in such points.

The present invention solves the above-mentioned drawbacks, and provides a safe drive unit for an electric vehicle and an electric vehicle which can be charged in a general household, and which is small, lightweight, efficient and safe.

[0005]

SUMMARY OF THE INVENTION The present invention comprises a battery,
A main circuit is composed of a traveling drive electric motor and a control device that supplies the electric power of the battery to the electric motor through electric power conversion means, and the main circuit also serves as battery charging means having a voltage conversion function. The present invention relates to improvement of a drive device for an electric vehicle.

According to one aspect of the present invention, the battery charging means is provided with a transformer means having only a magnetic portion of the stator of the electric motor as a magnetic circuit.

According to another aspect of the present invention, the battery charging means may be provided with a transformer means in which a winding for voltage conversion is arranged on the outer periphery of the stator of the electric motor.

According to another aspect of the present invention, in the battery charging means, a winding for voltage conversion is fixed to a transformer winding groove for accommodating the winding at a position on the outer periphery of the stator of the electric motor. A transformer means wound in a toroidal shape is provided between the motor winding grooves, which are located at the inner circumference of the child and accommodate the windings for driving the rotation of the electric motor, in the shape of a crotch of the stator. Further, according to another aspect of the present invention, the battery charging means is provided with a transformer means for forming a magnetic circuit only by the magnetic body portion of the stator of the electric motor, and the transformer means has a leakage magnetic circuit. It is a thing.

Further, according to another aspect of the present invention, there is provided an electric vehicle including a voltage converting means having only a magnetic body portion of a stator of an electric motor for traveling drive as a magnetic circuit.

[0010]

According to the present invention, the magnetic body portion of the stator of the electric motor forming the magnetic circuit when used as the electric motor and when acting as the transformer or the reactor is shared. At this time, the windings of the transformer and the reactor are arranged so that the magnetic flux density of the magnetic circuit is not increased more than necessary. As a result, it is possible to obtain the drive device for an electric vehicle in which the outer size of the electric motor is suppressed and the charging transformer and the reactor are built in the electric motor.

Further, since the magnetic circuit of the transformer or the reactor is formed only by the magnetic material portion of the stator of the electric motor, there is no air gap between the rotor and the stator on the magnetic circuit. Therefore, there is no reduction in transformer efficiency,
In the case of a basket-type induction motor, eddy current does not occur in the rotor, which is even better. Further, since there is no magnetic flux passing through the rotor, there is no fear that the rotor will rotate.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration and operation of an embodiment according to the present invention will be described below with reference to the drawings.

First, a schematic structure of a motor structure of a drive device for an electric vehicle will be described with reference to FIG. The electric motor 1 includes a frame 4, a stator core 5 fixed to the inner circumference of the frame 4, a stator winding 12A wound around the stator core 5, a motor winding 12A, a transformer winding 12B, and a reactor winding 12C. 2, shaft 6, rotor core 7 and rotor 8
The rotor 3 includes an end ring 11, a bracket 9 that holds the rotor 3 rotatably, and a bearing 10.

FIG. 1 shows a stator structure of an electric motor of a drive device for an electric vehicle. Stator core 5 of stator 2
Is composed of a core portion 5A, an iron core tooth portion 5B, a transformer and a second core portion 5C used for the reactor. Further, as shown in FIG. 1, the stator core 5 has a U of a three-phase power source.
Phase, V phase, W phase motor winding 12A, motor winding groove 1
It is wrapped in 3A. Where U-phase motor winding 1
2A constitutes one motor winding 12A with a set of U + and U-. The same applies to the V and W phase windings. This is no different from the winding of a general AC motor.

A transformer winding groove 13B and a reactor winding groove 13 are provided on the outer peripheral portion of the core portion 5A and the inner peripheral portion of the second core portion 5C.
C is provided. The transformer winding 12B and the reactor winding 12C are housed in this groove. FIG. 1 shows an example in which two transformer windings 12B and one reactor winding 12C are housed.

For example, the transformer winding groove 13B or the reactor winding groove 13C is not located back to back with the electric motor winding groove 13A, but is located at the radial outer periphery of the iron core tooth portion 5B. With such a positional relationship, the transformer winding groove 13B and the motor winding groove 13A
The thickness h1 in the radial direction of the core portion 5A sandwiched by and can be secured to a predetermined dimension. This leads to the advantage that the transformer winding 12B and the reactor winding 12C can be housed without increasing the magnetic flux density of the h1 portion of the core portion 5A. Therefore, the transformer and the reactor can be built in the electric motor without increasing the outer dimensions of the electric motor. In particular, it is even better if the shape of the motor winding groove 13A is semicircular. However, when the magnetic flux density has a margin, it is not necessary to be concerned with the above positional relationship.

On the other hand, considering the magnetic circuit on the transformer side, in order to improve the magnetic coupling between the primary winding A and the secondary winding B of the transformer winding 12B, the core portion 5A and the second core portion 5C are formed. It is better not to create a gap between and. On the other hand, considering the reactor side, it is better to provide the air gap 30 in the iron core portion inside the reactor winding 12C in order to avoid saturation of the magnetic flux even when a large current flows in the reactor winding 12C.

The radial thickness h3 of the second core portion 5C sandwiched between the transformer winding groove 13B dug in the second core portion 5C and the outer peripheral surface of the second core portion 5C, and the thickness h1 The sum should be equal to or larger than the radial thickness h2 of the core portion 5A, which is the original thickness of the stator core 5. This is because it does not affect the magnetic circuit as the electric motor. However, if it is taken too large, the external dimensions of the electric motor are increased. Therefore, 1.0 × h2 ≦
It is desirable in terms of external dimensions that the relationship of (h1 + h3) ≦ 2.0 × h2 is satisfied. The same can be said for the thicknesses h1, h2, h3 described above with respect to the reactor winding groove 13C.

Transformer winding 12B and reactor winding 12
Each of the transformer winding groove 13B and the reactor winding groove 13C in which C is stored may be a groove dug in either the outer peripheral portion of the core portion 5A or the inner peripheral portion of the second core portion 5C. However, in the former case, the thickness h1 may become too thin and affect the motor performance. In the latter case, the thickness of the second core portion 5C is increased, that is, the outer shape of the electric motor is increased. Therefore, as shown in FIG. 1, it is preferable to provide grooves in the core portion 5A and the second core portion 5C, respectively.
It is optimal and can be linked to the downsizing and weight reduction of electric motors.

For the sake of convenience, in FIG. 1, a transformer and a reactor are arranged at one location on the outer circumference of the core portion 5A. However, in order to obtain the same transformer capacity, it is better to disperse the second core portion 5C.
Since it can be made thinner, the overall outer shape becomes smaller, which is good for small size and light weight. If the external power supply is three-phase,
It suffices to provide the object having the above configuration at at least three places.

FIG. 3 shows a drive system for an electric vehicle according to an embodiment of the present invention. When traveling as an electric vehicle, the switching mechanism 17 is put in the A side. In this state, the electric power of the battery 14A is supplied to the electric motor 1 via the first control device 15A controlled by the first control circuit 16A, and by the operation of the electric motor winding 12A and the rotor 3,
The wheels 20 are rotated. On the other hand, when charging using a household power supply at night or the like, the switching mechanism 17 is turned on to the B side. As a result, the electric power of the household external power supply 14B is supplied to the transformer winding 12B and the reactor winding 1 inside the electric motor 1.
It is supplied to the first control device 15A in an electrically insulated state via 2C, rectified by the action of the first control device 15A, and charged in the battery 14A. At this time, the first
The control circuit 16A performs control so as to be compatible with the rectification control of the first control device 15A.

According to the above construction, no current is passed through the transformer winding 12B or the reactor winding 12C when the motor is rotating, and the motor winding 12 of the motor is charged when the battery is charged.
Since no current flows through A, the stator core 5 is shared,
The magnetic circuit of the electric motor 1 and the magnetic circuits of the transformer and the reactor can be compatible with each other. Therefore, incorporating a charging transformer does not lead to an increase in the size of the electric motor. In an electric vehicle, it is important to extend the mileage per charge of the battery. Therefore, it is necessary to avoid increasing the size of the component parts, and this method is also suitable for that purpose.

When a plurality of charging transformers and reactors are provided on the outer periphery of the electric motor, the structure can be further simplified by connecting them in the electric motor. That is, FIG.
The number of leads from the electric motor 1 can be minimized by adopting the configuration shown in.

In the above, the example of the induction motor is shown.
The present invention is applicable not only to induction motors but also to synchronous motors and reluctance motors. Generally, an external power source for household use is AC 100V, 50 to 60 Hz, so that the present invention can be applied to any electric motor having a laminated stator core. It is suitable for small and lightweight electric motors for electric vehicles with a built-in charging transformer.

FIG. 4 shows a stator structure of an electric motor of another embodiment. The shape and configuration of the motor winding groove 13A provided in the stator core 5 of the stator 2 are the same as those in FIG. A transformer winding groove 13B is provided on the outer peripheral portion of the stator core 5. The primary winding of the transformer is wound in a toroidal shape with the core portion 5A between the motor winding groove 13A and the transformer winding groove 13B being crotch-shaped. The secondary winding is similarly wound next to the primary winding. Here, six sets of primary windings and secondary windings are shown. The transformer winding 12B housed in one motor winding groove 13A of the stator core 5 is the primary winding, and the transformer winding 12B housed in the adjacent motor winding groove 13A is the secondary winding. When connected, it can function as a transformer for a single-phase power supply. In the case of a three-phase power source, the second core 5C is added to the outer circumference of the stator core 5. Although only one is shown in the figure, it is assumed that each transformer winding is also provided. With this configuration, the pair of adjacent primary and secondary windings for the transformer are, for example, three-phase U-phase primary and secondary windings and are independent of the magnetic circuits of the other windings. Configure. Then, by preparing three sets of these, it is possible to deal with a three-phase power supply. In the case of supporting both single-phase and three-phase, a separate mechanism for switching the connection of the winding 12B of the transformer is required.

FIG. 5 shows an embodiment in which not only the transformer winding 12B is charged, but also the three-phase toroidal winding structure shown in FIG.
First control circuit 16A and first control device 15A shown in FIG.
A second control circuit 16B and a second control device 15B having substantially the same configuration as the above and having a small capacity are provided. Further, by connecting the primary winding and the secondary winding of the transformer to the three-phase configuration as shown in the figure, it can be used as a motor winding. Even if this is not always used, the first control circuit 16A
Alternatively, it may be used only when the first control device 15A fails.
A limp home function capable of urgently moving a vehicle at the time of failure can be secured, and a highly reliable drive device for an electric vehicle can be provided. In this case, it is desirable that the second core 5C of the transformer shown in FIG. 4 has a movable structure.
That is, when used as a three-phase transformer, the second core 5C of the transformer is necessary from the magnetic circuit of the primary winding and the secondary winding, while as the electric motor, the second core 5C of the transformer is the electric motor of the electric motor. This is because it is better not to increase the driving force.

FIG. 6 shows another embodiment of the stator structure of the electric motor. In the figure, the shapes and configurations of the motor winding groove 13A and the motor winding 12A provided in the stator core 5 of the stator 2 are exactly the same as those in FIG. The primary winding and the secondary winding of the transformer are housed together in a transformer winding groove 13B elongated in the circumferential direction. The conductor cross-sectional shape of the winding is such that the length dimension L2 in the circumferential direction is larger than the length dimension L1 in the radial direction.

Generally, when a current is passed through the primary winding and the secondary winding of a transformer, a magnetic flux is generated around the winding. Of this magnetic flux, the magnetic flux that wraps around both the primary winding and the secondary winding contributes to the original transformer action. The magnetic flux that goes around only the primary winding and the secondary winding is a leakage magnetic flux, which lowers the efficiency of the transformer. However, in the case of the transformer action, by intentionally obtaining the leakage magnetic flux, an appropriate amount of the reactor component may be generated in the transformer and the same action as the reactor as shown in FIG. 3 may be caused.

According to the configuration of FIG. 6, since the length dimension in the circumferential direction is long, an appropriate amount of leakage magnetic flux escaping in the radial direction between the primary winding and the secondary winding is generated, and an appropriate amount of reactor component is generated. Can be held in a transformer. This has the advantage that there is no need to provide a separate reactor.

FIG. 7 shows another embodiment different from FIG.
Here, in the contact portion between the core portion 5A and the second core 5C, the central portion 31 inside the primary winding and the secondary winding of the transformer
No gap is provided in the outer end portion 32 to improve the magnetic coupling, and in the portion between the primary winding and the secondary winding,
It is configured such that the void portion 33 is provided. As a result, similarly to the case shown in FIG. 6, an appropriate amount of leakage magnetic flux is generated between the primary winding and the secondary winding, that is, an appropriate amount of reactor is provided in the transformer, and it is not necessary to provide a separate reactor. It is a thing.

Further, in the figure, the cooling pipe 23 is provided on the outer peripheral portion.
To place. The functions of the electric motor, transformer, and reactor are
It is no exaggeration to say that it depends on the cooling effect. Figure 7
As described above, by providing a common cooling mechanism for the electric motor, the transformer, and the reactor, for example, a liquid cooling mechanism, the size and weight can be further reduced.

Particularly, in the case of an electric vehicle, since the electric motor and the transformer are not used at the same time, the cooling is sufficiently performed, and the above-mentioned effect is further expected.

FIG. 8 shows an embodiment of an electric vehicle equipped with the drive device of the present invention. The electric motor 1 is shown in FIGS.
It has a built-in transformer shown in. The reactor winding 12C and the transformer winding 12B are connected in the electric motor 1. In the driving mode, the electric power of the battery 14A placed under the seat 22 is switched by the switching mechanism 17 and supplied to the electric motor 1 through the first control device 15A to generate the torque, and the speed change mechanism 19, Wheel 2 via axle 21
Rotate 0. External power supply 14B in charging mode
Is switched by the switching mechanism 17 to be connected to the transformer winding 12B and the reactor winding 12C in the electric motor 1, and is rectified and controlled by the first controller 15A (including power factor control if necessary), and the battery It is charged to 14A.

In the above, an example in which the transformer core and the winding of the reactor are provided on the stator core of the electric motor of the electric vehicle has been described. However, if the transformer has a small capacity, for example, an electric motor for an air conditioner used in an automobile. The effect of the present invention can be exhibited by winding a transformer or a reactor winding on the stator core.

FIG. 9 shows another embodiment of the drive system for an electric vehicle according to the present invention. The example which used the transformer for charge as a transformer for power supplies other than charge is shown. Figure 3
Although the configuration is almost the same as that of the above, the configuration is such that a changeover switch 25 and an outlet 24 are added. The power supply of the battery 14A is controlled by the inverter control of the first controller 15A.
Through the switching mechanism 17 and the changeover switch 25, both of which are turned on the B side, it can be taken out from the outlet 24 as a power source of AC 100 V, 50 Hz to 60 Hz, which is the same as a household power source, and can be used. In this case, the transformer first
Since the control device 15A and the outlet 24 are electrically insulated, a power source with less noise can be obtained. In addition, although the above has shown the case where it was used as a power transformer, it can also be used as a control transformer.

[0036]

According to the present invention, the stator core of the electric motor is shared with the core part of the magnetic circuit of the charging transformer, and the air gap between the rotor and the stator is avoided to avoid the stator core. By forming the magnetic circuit only inside, the eddy current is not generated, the transformer efficiency is improved, and the charging transformer is small and lightweight. This makes it possible to mount an electric motor that doubles as a charger on the vehicle, and because the electric motor is inadvertently rotated and the vehicle electrical system and the household power supply are insulated, it can be charged in a general household and is compact and lightweight. It is possible to provide a drive device for an electric vehicle having a good and safe charging function and an electric vehicle equipped with the drive device.

[Brief description of drawings]

FIG. 1 shows a stator structure according to an embodiment of the present invention.

FIG. 2 shows an electric motor structure of an embodiment according to the present invention.

FIG. 3 shows a driving device for an electric vehicle according to an embodiment of the present invention.

FIG. 4 shows a stator structure according to another embodiment of the present invention.

FIG. 5 shows a drive device for an electric vehicle according to another embodiment of the present invention.

FIG. 6 shows a stator structure according to another embodiment of the present invention.

FIG. 7 shows a stator structure according to another embodiment of the present invention.

FIG. 8 shows an electric vehicle equipped with the drive device for an electric vehicle of the present invention.

FIG. 9 shows a drive device for an electric vehicle according to another embodiment of the present invention.

[Explanation of symbols]

1: Electric motor 2: Stator 3: Rotor 5: Stator core 5A: Core part 5B: Iron core tooth part
5C: 2nd core part 12A: Motor winding 12B: Transformer winding 12
C: Reactor winding 13A: Motor winding groove 13B: Transformer winding groove 13
C: Reactor winding groove 14A: Battery 14B: External power supply 15A: First control device 15B: Second control device 17: Switching mechanism 24: Outlet 2
5: Changeover switch

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Taizo Miyazaki 7-1-1 Omika-cho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi Research Laboratory (72) Inventor Nobuyoshi Muto 7-chome, Omika-cho, Hitachi-shi, Ibaraki No. 1 Hitachi Ltd., Hitachi Research Laboratory (72) Inventor Riki Omae 7-1, 1-1 Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi Ltd. Hitachi Research Laboratory (72) Inventor Osamu Koizumi Katsuta City, Ibaraki Prefecture 2520, Takaba, Oji Inside the Automotive Equipment Division, Hitachi, Ltd.

Claims (16)

[Claims] 1. A main circuit comprises a battery, an electric motor for driving the vehicle, and a controller for supplying the electric power of the battery to the electric motor through an electric power conversion means, and the main circuit has a voltage conversion function. In a drive device for an electric vehicle which is also used as a battery charging means, the battery charging means is provided with a transformer means having only a magnetic body portion of a stator of the electric motor as a magnetic circuit. Drive. 2. A drive device for an electric vehicle according to claim 1, wherein the transformer means and a reactor means forming a magnetic circuit only with the magnetic material portion are arranged in parallel. 3. The drive device for an electric vehicle according to claim 1, wherein at least two sets of the transformer means are provided in a dispersed manner. 4. A drive unit for an electric vehicle according to claim 1, wherein the transformer means has a cooling mechanism. 5. The drive device for an electric vehicle according to claim 1, wherein the winding of the transformer means is arranged between the outermost diameter and the innermost diameter of the magnetic body portion. . 6. The iron core in a radial direction of the magnetic body portion defined by claim 1, which is sandwiched between a transformer winding groove for accommodating a winding of the transformer means and an outermost diameter of the magnetic body portion. The sum of the thickness and the radial iron core thickness of the magnetic body portion sandwiched between the transformer winding groove and the motor winding groove that houses the rotation driving winding of the electric motor is the maximum of the magnetic body portion. A drive device for an electric vehicle, which is larger than 1 time and smaller than 2 times the thickness of the iron core in the radial direction of the magnetic body portion sandwiched by the outer diameter and the motor winding groove. 7. The drive system for an electric vehicle according to claim 2, wherein the transformer means and the reactor means are electrically connected to each other inside the electric motor. 8. A drive device for an electric vehicle according to claim 2, wherein the reactor means has a leakage magnetic circuit. 9. The electric vehicle according to claim 8, wherein the leakage magnetic circuit is provided with an air gap in a magnetic body portion through which a magnetic flux inside the winding of the reactor means passes. Drive device. 10. A main circuit comprises a battery, an electric motor for driving the vehicle, and a control device for supplying electric power of the battery to the electric motor through an electric power converting means, and the main circuit has a voltage converting function. In the drive device for an electric vehicle which is also used as the battery charging means, the battery charging means includes a transformer means in which a winding for voltage conversion is arranged on an outer periphery of a stator of the electric motor. Drive device for electric vehicle. 11. A main circuit comprises a battery, an electric motor for driving the vehicle, and a controller for supplying the electric power of the battery to the electric motor through an electric power converting means, and the main circuit has a voltage converting function. In an electric vehicle drive device which is also used as a battery charging means, in the battery charging means, a winding for voltage conversion is located at an outer peripheral position of a stator of the electric motor, and a transformer winding groove for accommodating the winding is provided. And a transformer means that is wound in a toroidal shape in the form of a crotch of the stator between an electric motor winding groove that is located on the inner circumference of the stator and that accommodates a rotation driving winding of the electric motor. A drive device for an electric vehicle, comprising: 12. A main circuit comprises a battery, an electric motor for driving the vehicle, and a controller for supplying the electric power of the battery to the electric motor through an electric power converting means, and the main circuit has a voltage converting function. In the drive device for an electric vehicle which is also used as the battery charging means, the battery charging means includes a transformer means having only a magnetic body portion of a stator of the electric motor as a magnetic circuit, and the transformer means includes:
A drive device for an electric vehicle having a magnetic leakage circuit. 13. The leakage magnetic circuit according to claim 12, wherein the primary winding and the secondary winding of the transformer means are provided in close contact with each other, and the conductor cross-sectional shapes of both windings are provided. In the drive device for an electric vehicle, the length dimension in the circumferential direction is set larger than the length dimension in the radial direction. 14. The leakage magnetic circuit according to claim 12, wherein a gap is provided in a magnetic body portion through which a magnetic flux passes between the primary winding and the secondary winding of the transformer means. A drive device for an electric vehicle characterized by: 15. An electric vehicle according to claim 1, 10 or 11 or 12, wherein the transformer means is also used as a power transformer or a control transformer. Drive. 16. An electric vehicle comprising a voltage converting means having only a magnetic body portion of a stator of a driving electric motor as a magnetic circuit.