JPH07111710A - Hybrid power supply for electric vehicle - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To reduce the temporary load on the battery when starting the engine generator, to increase the distance that the battery can travel, and to improve the running electric motor when starting the engine generator. Suppress temporary effects on output. In a hybrid power supply device for an electric traveling vehicle, which includes a battery 10 for driving an electric motor 14 serving as a travel drive source, and an engine-driven generator 3 that supplies power to the battery, a generator is provided while the engine 2 is operating. To operate as a generator and output this output to the inverter unit 2
1, 15 is rectified and supplied to the battery 10, and at the time of starting the engine 2, a gentle rising voltage is applied from the battery to the generator via the inverter unit to operate as an engine starting electric motor. It is characterized by

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid power supply device for supplying electric power to an electric motor in an electric vehicle which is driven by driving the electric motor.

[0002]

2. Description of the Related Art In recent years, electric running vehicles that are pollution-free and noise-free and easy to operate are attracting attention and are being put into practical use.
The biggest problem of the electric traveling vehicle is that the battery that stores the electric power supplied to the electric motor has a large capacity and a large number of batteries must be mounted in order to extend the travelable distance in one battery charging.

Therefore, as described in, for example, Japanese Patent Application Laid-Open No. 55-157901, an electric power traveling vehicle has been proposed which is provided with a so-called hybrid power supply device equipped with an engine generator that automatically operates according to the state of charge of a battery. .

[0004]

[Problems to be Solved] By the way, in recent years, electric vehicles have come to be used more and more from the viewpoint of environmental protection such as the absence of exhaust gas as in vehicles powered by an engine. It is preferable to reduce the engine operation as much as possible, for example, to operate the engine generator as an emergency when the remaining battery level is low before the vehicle reaches the battery charging station.

However, this type of engine generator is
When the terminal voltage of the battery that becomes the power source of the traveling electric motor or the so-called battery remaining amount such as the specific gravity of the electrolyte is low, the electric motor for starting the engine is driven to start the power generation operation. Since the electric current is very large, when the starting battery is also used as the traveling battery, the temporary burden on the battery having a low remaining battery amount is considerably large.

For this reason, it is necessary to turn on the electric motor for starting the engine while there is a sufficient margin in the remaining battery amount, which causes a problem that the number of times the engine is operated increases by the excessive margin in the remaining battery amount.

Furthermore, when the electric motor for starting the engine is turned on while the vehicle is running with the remaining battery level reduced, the output of the electric motor for traveling may be temporarily affected.

The present invention has been made in view of the above points, and a purpose thereof is to provide a hybrid power supply device in which a generator of an engine generator is connected to a battery common to a traveling electric motor as a generator also serving as an electric motor. By reducing the load on the battery at the time of starting the engine, the engine can be started sufficiently even if the remaining battery capacity is reduced, and it is possible to rely on the electric energy generated by the operation of the engine generator. An object of the present invention is to provide a hybrid power supply device for an electric vehicle that can travel as long as possible with only the charging energy of the battery and can easily suppress the temporary influence on the output of the electric motor for traveling at this time.

[0009]

In order to achieve the above object, the present invention provides a battery for driving an electric motor which is a traveling drive source, and an engine-driven generator that supplies power to the battery. In the hybrid power supply device for an electric vehicle, the engine-driven generator includes an engine, a generator that is driven by the engine and also serves as an electric motor, and an inverter unit that is interposed between the electric motor and generator and the battery. While the engine is in operation, the generator that also serves as the electric motor is operated as a generator to rectify this output by the inverter unit and supply it to the battery, and at the time of starting the engine, the inverter unit from the battery. A voltage with a gentle rise can be applied to the generator that also serves as the motor through And a hybrid power supply device for an electric vehicle traveling configured to operate as an engine starting motor by.

When the engine is started, the generator which also serves as the electric motor is operated as an electric motor for starting the engine by applying a voltage with a gentle rising, so that a temporary large current such as an inrush current at the time of starting is suppressed and the battery is supplied to the battery. It becomes possible to start the engine with at least a sufficient margin of the remaining battery capacity and to easily suppress the temporary influence on the output of the traveling electric motor at the time of starting.

[0011]

EXAMPLES An example of the present invention shown in FIGS. 1 to 4 will be described below. The engine generator 1 of this embodiment includes an engine 2 and a generator 3 that also serves as an electric motor and includes an outer rotor type magnet rotor (not shown) directly connected to a crankshaft of the engine 2. The dual-purpose generator 3 operates as a generator by the driving force of the engine 2 and supplies power to the main battery 10, while it also operates as an electric motor by the power supply from the main battery 10 to start the engine 2. Engine 2 and generator 3
Since it is directly connected, there is no gear noise when starting.

FIG. 1 shows a block diagram of a hybrid power supply system constructed by incorporating the engine generator 1 as described above. The main battery 10, which is the power source, is a vehicle-mounted charger 11
Is configured so that a normal charging operation can be performed from an external power source such as a charging station via the external power source connection terminal 12, and the output of the main battery 10 is controlled by the inverter 13 to be supplied to the traveling motor 14. As a result, the drive motor 14 is drive-controlled.

An engine generator 1 is incorporated as a self-charging mechanism. The generator 3 generates power by driving the engine 2, and the three-phase power is rectified by flywheel diodes in the inverter unit 50. The circuits 15 are configured to be full-wave rectified and summed, and supplied to the main battery 10.

An overvoltage detector 20 is provided for detecting the output voltage of the generator 3 when it exceeds a predetermined voltage. When the overvoltage detector 20 detects the overvoltage, the ignition signal of the engine 2 is turned off. Is configured to stop the engine 2.

Further, as described above, the generator 3 is configured as a generator that also serves as an electric motor. Conversely, the electric power of the main battery 10 is supplied to the generator 3 via the inverter 21 in the inverter unit 50 to serve as an electric motor. By driving, the engine 2 can be made to act as a starter motor for starting the engine 2.

Therefore, the starting switch 16 of the inverter 21,
17 is provided, one start switch 16 is a switch that is manually turned on and off based on a monitor display such as a charging state display lamp (not shown), and the other start switch 17 is a voltage that detects the voltage of the main battery 10. Detector
When the voltage of the main battery 10 drops below a predetermined value based on the detected voltage of 18, the inverter automatically turns on and the inverter 21
Is a switch that is controlled to start.

FIG. 2 shows a connection configuration example of the generator (generator that also serves as an electric motor) 3, the inverter unit 50 and the main battery 10. A three-phase inverter 21 that supplies the power of the main battery 10 to the generator 3 by means of six transistors 22.
And the six flywheel diodes 23 connected in parallel with the respective transistors 22 rectify and sum the output of the generator 3 and supply it to the main battery 10.
A phase bridge current circuit 15 is configured. Each transistor 22 is controlled to be turned on / off by the ECU 30.

A magnetic pole sensor 31 is provided in the generator 3 to detect the rotation timing (magnetic pole position) of the outer rotor and send a signal to the ECU 30, which in turn outputs the signal from the inverter 21 to the inverter 21. Each transistor 22
Chopper control.

The output terminal of the rectifier circuit 15 is connected to the +-terminal of the main battery 10 with the capacitor 32 interposed.

While the generator 3 is generating power, the outputs of the respective generator coils 4 are full-wave rectified and summed by the rectifier circuit 15 and supplied to the main battery 10.

When the engine is started, the ECU 30 outputs a drive signal matched with the magnetic pole of the generator 3 (the magnetic pole position of the rotor) to the inverter 21 by turning on the switch 16 or 17.
Power is supplied from the main battery 10 to the generator 3 to drive the generator (= electric motor) 3 in a synchronous oscillation mode. Since the generator has a large output and a small winding resistance and high efficiency, it also has a good performance as an electric motor and can start the engine with less electric power.

Since the generator winding has a low resistance, the power supply is controlled particularly immediately after starting. That is, when the remaining battery level of the main battery 10 decreases, the voltage decreases accordingly, and the voltage detector 18 detects this and detects that the voltage has dropped below the predetermined voltage value, and the start switch
17 is automatically added.

When the start switch 17 is turned on, the ECU 30 starts supplying the drive signal to the inverter 21 and
The chopper control 21 is performed, the duty ratio is reduced immediately after the start of the supply of the drive signal, and then the duty ratio is gradually increased to gradually suppress the rise of the power supplied from the main battery 10.

Further, since the generator 3 which also serves as an electric motor is constructed so as to be driven to rotate at a high speed in order to enhance the efficiency of the generator driven by the engine 2, this generator 3 is used.
When the output voltage of the main battery 10 is directly applied to the motor, the rotation speed becomes too high for the engine starting motor.Therefore, by setting the duty ratio of the drive signal for controlling the inverter 21 to a predetermined value or less, Is kept low and the speed is lowered to a value suitable for starting the engine as an electric motor. FIG. 3 shows the characteristics of the inverter output voltage at the time of starting controlled in this way as a model.

By the chopper control of the inverter 21, the current supplied from the main battery 10 to the electric motor (generator 3) is suppressed as shown in a model in FIG. It is possible to suppress a large current.

In particular, since the engine is started when the remaining amount of the main battery 10 is low, that is, when the main battery 10 is weak, the burden on the battery in this weak state is greatly reduced. It becomes easier to start the engine without having too much power, and it becomes possible to extend the distance that can be traveled only by the charging energy of the battery.

Even when the engine is started during running, the temporary large current due to the engine start is suppressed, so that the power supply to the running motor 14 of the main battery 10 and the output of the running motor 14 are affected. Can be easily suppressed.

When the generator 3 is rotating as an electric motor, the number of rotations is smaller than when rotating as a generator. Therefore, by detecting this number of rotations by the magnetic pole sensor 31, the generator 3 is generated. It can be easily determined which of the two is operating as an electric motor.

Further, in this embodiment, when the remaining battery level was low, it was detected when the terminal voltage was lower than the predetermined value, but when the specific gravity of the electrolyte of the main battery 10 was lower than the predetermined value. Other means such as detection of can be used as appropriate.

[0030]

As described above, according to the present invention, when the engine is started, the generator which also serves as the electric motor is supplied with a gently rising applied voltage to operate as the electric motor for starting the engine. Therefore, a temporary large current such as a rush current at the time of starting is generated. You can significantly reduce the temporary burden on the weak battery by suppressing it,
As a result, there is no need to excessively allow the remaining battery capacity to start the engine generator,
It is possible to increase the distance that can be traveled using only the charging energy of the battery. Further, it is possible to easily suppress a temporary influence on the output of the traveling electric motor that tends to occur when the engine is started.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a power supply system according to an embodiment of the present invention.

FIG. 2 is a connection configuration diagram of a generator, an inverter unit, and a main battery.

FIG. 3 is a diagram showing an output voltage characteristic of the inverter when the engine power generation is started.

FIG. 4 is a diagram showing a battery discharge current at the time of starting the engine generator.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine generator, 2 ... Engine, 3 ... Generator that also serves as an electric motor, 4 ... Generator coil, 10 ... Main battery, 11 ... In-vehicle charger, 12 ... External power supply connection terminal, 13 ... Inverter, 14
… Traveling motor, 15… rectifier circuit, 16,17… starting switch, 18… voltage detector, 20… overvoltage detector, 21… inverter, 22… transistor, 23… diode, 30… ECU,
31 ... Magnetic pole sensor, 32 ... Capacitor, 50 ... Inverter unit.

Claims (2)

[Claims] 1. A hybrid power supply device for an electric traveling vehicle, comprising: a battery for driving an electric motor that is a travel drive source; and an engine-driven generator that supplies power to the battery, wherein the engine-driven generator is an engine. And a generator that also serves as an electric motor driven by this engine, and an inverter unit that is interposed between the generator that also serves as the electric motor and the battery. While the engine is operating, the generator that serves as the electric motor also serves as a generator. And rectifying this output by the inverter unit and supplying the same to the battery, and at the time of starting the engine, applying a gentle rising voltage from the battery to the electric motor / generator via the inverter unit. Is configured to operate as an electric motor for starting the engine. And a hybrid power supply device for an electric vehicle. 2. The engine is automatically operated by applying a gentle rising voltage from the battery to the generator that also serves as the electric motor through the inverter unit when the remaining battery level of the battery drops below a predetermined value. A hybrid power supply device for an electrically driven vehicle, which is configured to start driving automatically.