JPH09322412A - Induction charger for electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify and lighten a rectifier for an electric vehicle. SOLUTION: In a device which charges the battery of an electric vehicle, with its induction connector 4 connected to this electric vehicle equipped with an inverter circuit 2 for motor drive, a first switch 17 is installed between the induction charge connector 4 and the inverter circuit 2, and a second switch 18 is installed between the inverter circuit 2 and a motor 1. At charge, the first switch 17 is closed, and the second switch 18 is opened, and the free wheel diodes 11, 12, 14, and 15 of the inverter circuit 2 are used as rectifying circuits. Moreover, at running of the electric motorcar, the first switch 17 is opened, and the second switch 18 is closed, and the motor is supplied with power from the battery 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery charging mechanism for electric vehicles.

[0002]

2. Description of the Related Art As an induction charging mechanism for an electric vehicle, the one shown in FIG. 2 is known. In the figure, the right side of the induction charging connector is the electric vehicle side, and the left side is the charger side. The high frequency power source 19 of the charger is connected to the electric vehicle through the induction charging connector 4. A rectifier circuit 20 composed of a diode is provided on the electric vehicle side and is connected to the battery 3. Further, the battery 3 is connected to the motor 1 via the inverter circuit 2. The high frequency power supplied from the charger is sent to the vehicle side through the connector 4, and the rectifier circuit
After being rectified by 20, the battery 3 is charged. When the electric vehicle is running, current is supplied from the battery 3 to the motor 1 via the inverter circuit 2.

[0003]

However, when the rectification circuit of the above charging mechanism performs rectification, some loss occurs and heat is generated. Particularly, when rapidly charged, the amount of heat generated is large. Therefore, a cooling device (heat sink, heat sink,
A heat pipe, an air cooling device, a water cooling device, etc.) are provided. As a result, the rectification mechanism is large, heavy, and expensive. A main object of the present invention is to provide an induction charging mechanism that can simplify and reduce the weight of a vehicle rectifier.

[0004]

SUMMARY OF THE INVENTION An induction charging device for an electric vehicle according to the present invention is an apparatus for charging an electric vehicle having an inverter circuit for driving a motor with an induction connector to charge a battery of the electric vehicle. A first switch is provided between the charging connector and the inverter circuit, and a second switch is provided between the inverter circuit and the motor. During charging, the first switch is closed and the second switch is opened to use the freewheel diode of the inverter circuit as a rectifier circuit. Further, when the electric vehicle is traveling, the first switch is opened and the second switch is closed to supply electric power from the battery to the motor. Here, it is desirable to use semiconductor power devices for both the first and second switches.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. FIG. 1 is a block diagram of the charging device of the present invention. The right side of the induction charging connector in the figure is the electric vehicle side, and the left side is the charger side. The electric vehicle includes a motor 1 for driving the vehicle, an inverter circuit 2, a battery 3 for driving the motor, and a socket 4A for an induction charging connector 4. The battery 3 is connected to the motor 1 via the inverter circuit 2. Further, the socket 4A is also connected to the battery 3 via the inverter circuit 2.

The inverter circuit 2 includes switching elements 5 to 5.
10 and freewheeling diodes 11 to 16 connected in parallel with the respective switching elements 5 to 10. Although not shown, the circuit 2 is also provided with a cooling device. A first switch 17 is provided between the socket 4A and the inverter circuit 2 of such an electric vehicle, and a second switch 18 is provided between the inverter circuit 2 and the motor 1.

On the other hand, the charger side has a high frequency power supply 19. The power source 19 is connected to the plug 4B of the induction charging connector 4 which engages with the socket 4A. To charge the battery 3, first insert the plug 4B into the socket 4A. Then, the first switch 17 is closed, the second switch 18 is opened, and the switching elements 5 to 10 are opened. As a result, the battery 3 is charged from the charger (high frequency power source 19) via the induction charging connector 4. At that time, the free-wheel diodes 11, 12, 14, 15 of the inverter circuit 2 constitute a full-wave rectifier circuit and function as a rectifier. Since the second switch 18 is opened, the high frequency AC voltage is not applied to the motor 1.

When the electric vehicle is driven, the first switch 17 is opened and the second switch 18 is closed. of course,
Remove the plug 4B of the connector 4 from the socket 4A. In this case, current is supplied from the battery 3 to the motor 1, and the electric vehicle can be driven. At that time, the switching elements 5 to 10 and the freewheel diodes 11 to 16 function as an inverter circuit for driving the motor.

If semiconductor power devices are used for the first and second switches 17 and 18, this switching can be automated, which is convenient. In the above description, a three-phase motor is taken as an example, but the present invention can be applied to an AC motor having two or more phases.

[0010]

As described above, according to the charging device of the present invention, the freewheel diode of the inverter circuit for driving the motor can be used also as the rectifying circuit for charging. That is, the freewheel diode and the cooling device can be used as both the rectifier circuit of the charging device and a part of the motor driving inverter circuit, and the weight and cost of the charging mechanism can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic view of a charging device of the present invention.

FIG. 2 is a schematic view of a conventional charging device.

[Explanation of symbols]

1 motor 2 inverter circuit 3 battery 4
Connector 4A Socket 4B Plug 5-10 Switching element 11-16 Freewheel diode 17 First switch 18 Second switch 19 High frequency power supply

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical indication location H02J 17/00 H02J 17/00 B H02M 7/06 8726-5H H02M 7/06 G 7/5387 9181 -5H 7/5387 Z

Claims (2)

[Claims] 1. An inductive charging apparatus for an electric vehicle, comprising an inverter circuit for driving a motor to charge a battery of an electric vehicle via an inductive charging connector, wherein a first switch is provided between the induction charging connector and the inverter circuit. A second switch is provided between the inverter circuit and the motor.When charging, the first switch is closed and the second switch is opened to use the freewheel diode of the inverter circuit as a rectifier circuit. An induction charging device for an electric vehicle, characterized in that one switch is opened and the second switch is closed to supply electric power from a battery to a motor. 2. The induction charging device for an electric vehicle according to claim 1, wherein semiconductor power devices are used for both the first and second switches.