JPH0614415A - Control device for electric vehicle - Google Patents

Abstract

(57) [Summary] [Purpose] To eliminate the problem that even a motor using a shunt coil does not start immediately when starting from the middle of a slope. [Constitution] In an electric vehicle control device comprising a motor having a shunt coil in a battery field, a motor rotation detector, an accelerator having an electric signal, a brake switch, and a motor control device having a microcomputer capable of running and regenerating, The microcomputer detects when the motor rotation speed is 0 and receives a signal that the brake switch is stepped on for a specified time or longer, and the field current control circuit is operated so that the field coil current becomes a power running operation. It is composed of a control circuit that causes the motor current to increase so that the motor current is increased to 0 when it is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an electric vehicle, and more particularly to a control device having a shunt coil in a motor and suitable for controlling a shunt coil current according to an operating state.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 62-20795 is a conventional method for controlling the field current of a DC motor. According to this method, only the speed is increased, and no fine control is performed.

A method is used in which this drawback is dealt with by controlling the motor using a shunt coil. That is, the shunt coil current (field current) is controlled according to the armature current of the motor, or the shunt coil current (field current) is controlled by the number of revolutions.
By controlling, the maximum speed is increased by efficient driving and field weakening. Then, in order to perform power running / regeneration, control is performed to switch the direction in which the current (field current) of the shunt coil flows.

However, since the inductance of the shunt coil is large, it takes time to switch between power running and regeneration, so that there is a problem that the vehicle does not start immediately when starting from the middle of the slope.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to perform control without using the problem that even a motor using a shunt coil does not start immediately when starting from the middle of a slope.

[0006]

[Means for Solving the Problems] (1) Means for detecting that the brake pedal is stepped on, Means for detecting that the number of rotations of the motor is 0, and Detecting that this state has continued for a certain specified time Means, means for continuing to flow a minute amount of field current in power running mode, means for supplying an armature current so that the motor speed becomes 0 when the brake petal is released, and normal operation when the accelerator petal is depressed It consists of means.

(2) The shunt winding coil is connected to a transistor bridge, and is composed of means for detecting the current of the shunt winding coil and means for feeding back the current to flow a field current.

[0008]

[Operation] (1) When the brake pedal is stepped on, the number of rotations of the motor is 0, and this state continues for a certain specified time.
Detects that the car has stopped.

When the brake pedal is stepped on, the vehicle continues to stop due to the mechanical braking force of the brake. Since the field current that enters the powering mode is made to flow minutely, the delay of the rising of the current does not matter. Next, when the means for supplying the armature current operates so that the rotation speed of the motor becomes 0 when the brake petal is released, the armature current immediately generates a torque for rising power running. The vehicle continues to stop because the means for supplying the armature current operates so that the rotation speed of the motor becomes zero.

Then, when the accelerator pedal is depressed, a means for becoming a normal driving works and the vehicle starts.

(2) After switching the field current including switching between power running and regeneration, the voltage continues to be applied until the current decreases to zero and reaches the command current value. After that, the chopper operation is performed so as to maintain the command current value.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A description will be given below with reference to FIG.

The charging breaker 2 is connected from the battery 1, the fuse 3, the breaker 4 to the (+) power supply line 5, the power running
Switching contactor 6 for regeneration, DC reactor 7 Motor 8
Armature 9, current sensor 10, armature chopper circuit 11
Are connected in series and are connected to the (−) power supply line 12.

The movable piece 13 of the switching contactor 6 is made to power as shown by the dotted line. The free wheel diode 14 is
It becomes a diode for charging during regeneration. The diode D (A) is for energizing the trip coil 15 of the breaker 5 and energizing the battery 1 when an excessive voltage is generated when the contacts are disconnected so that the voltage does not exceed the battery voltage.

From the (+) power line 5 to the current sensor (B) 1
6. The transistor bridge 17 is connected in series to the (-) power supply line 12. (+) Power line 3 and (-) power line 12
A diode bridge 18 is connected to and the field winding shunt coil 19 of the motor 8 is connected to the middle point of each bridge.

The control circuit 20 includes an input circuit 21 and a microcomputer 2.
2 and output circuit 23, etc.
Signals from 4 (current sensor, accelerator signal, brake signal) are processed by the control circuit 20 and the armature chopper circuit 1
1. Apply a signal to the transistor bridge 17 to rotate the motor 8.

FIG. 1 shows the field control circuit of the present invention.

The (+) power supply line 5 is connected to the low voltage generation circuit 27 through the high voltage generation circuit 25 and the filter 26.
The filter 26 includes an inductance, a resistance and a capacitor. The low voltage generating circuit 27 is composed of a switching element 28, an inductance, a resistor, a capacitor, a switching transistor, etc., and supplies a constant voltage of about 6 V to the drive circuit (A) 29 and the drive circuit (B) 30.

The field control in the power running state is to make the transistors T1 and T4 of the transistor bridge 17 conductive. The transistor T1 is turned on by turning on the transistor T5. The transistor T4 performs a chopper operation, and feedback control is performed by the signal of the current sensor (B) 16 so that a specified current value is obtained. When the transistor T4 performs the chopper operation and turns off, the collector voltage becomes larger than that of the (+) power supply line 5. This voltage is applied to the high voltage generation circuit 25 via the diode D1.

The capacitor T1 is charged by the transistor T7. The diodes D3 and D4 and the resistor R1 prevent excessive current from flowing. Operational amplifier OPAM
When the voltage of the capacitor C1 increases due to P, resistance, and zener diode, the transistor T8 is turned on and the transistor T7 is turned off so that an excessive voltage is not generated.

Thus, the voltage of the (+) power supply line 5 is about 6
By controlling the voltage of the capacitor C1 so as to increase by about V, when the transistor T1 or T2 of the transistor bridge 17 is turned on, the base voltage becomes higher than the collector voltage and can be saturated.

This effect is shown in FIG. 3 (see FIG. 2).

During the times T1 and T2, the transistor T1 is in the ON state and the transistor T4 is in the chopper operation state. In the chopper operating state, the collector voltage becomes larger than the (+) power supply line 5 for a short time (several milliseconds) due to the inductance of the (+) power supply line 5 and the (-) power supply line 12 when it is turned off. . This voltage is taken into the diode D1 and the voltage of the capacitor C1 is increased. Similarly, during the times T3 and T4, the transistor T2 is in the ON state and the transistor T3 is in the chopper operation state. Then, when the transistor T3 is turned off, the collector voltage becomes larger than that of the (+) power supply line 5. This voltage is taken into the diode D2 and the voltage of the capacitor C1 is increased.

The characteristics indicated by the dotted lines (d) and (e) are conventional.

FIG. 4 shows the control operation of the motor according to the present invention.

Time T1 indicates the time when an electric input signal indicating that the brake pedal is released, an electric input signal indicating that the accelerator pedal is released, and an electric input signal indicating that the rotation of the motor 8 is 0 occur at the same time. When t1 is exceeded (T2), the power running mode is set and the field coil current is supplied for about 1/10 of the maximum current. When the brake pedal is released (T3), the armature current and the field current are adjusted so that the rotation speed becomes 0, and when there is an electric input signal that the accelerator pedal is depressed (T4), normal control is performed.

FIG. 5 shows a flowchart of the software of the microcomputer 22 that performs this control.

FIG. 6 is a diagram for explaining the operation when the tilt sensor is used for the sensors 24.

When there is an electric signal indicating that the brake pedal is depressed and the accelerator pedal is released to incline the inclination sensor (when the rotation is 0, that is, there is no acceleration, gravity
(The principle of a level or the like is used.) At T2 after a certain time t2 from T1, the mode is switched to the power running mode. If the brake pedal is continuously depressed, the field coil current is supplied and the armature current is supplied when the brake pedal is released. Do not let you go downhill.

FIG. 7 shows a field control circuit according to another proposal.

The switching of the current of the field coil 19 is performed by the contactor (A) 31 and the contactor (B) 33, and the energization of the coil 32 of the contactor (A) and the coil 34 of the contactor (B) is selected. The selection of energization is performed by the field effect transistors FET1 and FET2. The coil 32 of the contactor (A), the field effect transistor FET1, and the Zener diode ZD are connected in series from the (+) power supply line 5 to the (-) power supply line 12.

From Zener diode ZD to drive circuit 2
9 is connected to the base of the transistor (T) 35. A surge absorbing circuit 36 is connected to the collector and emitter of the transistor (T) 35. Since the coil current can be used as the base current of the transistor (T) 35, there is an advantage that no special power supply circuit is required.

A surge absorber 38 that absorbs the coil current using a transistor (Z) 37 in which a zener diode is connected between the collector and the base to absorb the surge when the coil current is cut off accelerates switching of the contactor.

The constant voltage circuit 39 is used in the control circuit 20.

FIG. 8 shows control characteristics for speeding up switching of the field current in addition to speeding up switching of the contactor.

FIG. 8 shows the control of the transistor (T) 35 for switching the field current quickly.

After T1 and T2 at which the contactor coil voltage is switched and the contact is switched, the transistor (T) 35 is fully turned on. The field current suddenly decreases to zero, and then returns to the chopper operation at T4 when the command value reaches the increasing value.

[0038]

EFFECT OF THE INVENTION When the vehicle was stopped on the slope and started, it was possible to start without moving backward. It was possible to speed up the current switching by feeding back the current value. The circuit configuration has become simple.

[Brief description of drawings]

FIG. 1 is a field control circuit diagram according to the present invention.

FIG. 2 is a circuit diagram showing an entire motor drive.

FIG. 3 is an explanatory diagram of a transistor bridge circuit of FIG.

FIG. 4 is an operation explanatory diagram of FIG. 1.

5 is a software flowchart of FIG. 1. FIG.

FIG. 6 is a diagram illustrating a control operation using a tilt sensor.

FIG. 7 is another field control circuit diagram according to the present invention.

8 is an explanatory diagram of a field current switching operation of FIG. 7.

[Explanation of Codes] 1 ... Battery, 2 ... Charge breaker, 3 ... Fuse, 4
… Breaker, 5… (+) power line, 6… Switching contactor, 7
... DC reactor, 8 ... Motor, 9 ... Armature, 10 ... Current sensor, 11 ... Armature chopper circuit, 12 ... (-) Power supply line, 13 ... Movable piece, 14 ... Free wheel diode,
15 ... Tripping coil, 16 ... Current sensor (B), 17
… Transistor bridge, 18… Diode bridge,
19 ... Shunt coil, 20 ... Control circuit, 21 ... Input circuit,
22 ... Microcomputer, 23 ... Output circuit, 24 ... Sensor, 25
... high voltage generating circuit, 26 ... filter, 27 ... low voltage generating circuit, 28 switching element, 29 ... drive circuit
(A), 30 ... Drive circuit (B), 31 ... Contactor (A), 32 ... Contactor (A) coil, 33 ... Contactor (B), 34 ... Contactor (B) coil, 35 ... Transistor (T), 36 ... surge absorption circuit, 37 ... transistor (Z), 38 ... surge absorption, 39 ... constant voltage circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuo Inoue 2520 Takaba, Katsuta City, Ibaraki Prefecture Hitachi Ltd. Automotive Equipment Division

Claims (2)

[Claims] 1. An electric vehicle control device comprising a motor having a shunt coil in a battery field, a motor rotation detector, an accelerator having an electric signal, a brake switch, and a motor control device having a microcomputer capable of running and regenerating power. In, the microcomputer detects when the motor rotation speed is 0 and the brake switch is depressed for more than the specified time, and the field current control circuit is operated so that the field coil current is in the power running mode. A control circuit that increases the motor current when the microcomputer detects it so that the motor rotation speed becomes 0, and when the accelerator is depressed next, controls the accelerator to perform a powering operation according to the depression amount. Control unit for electric vehicles. 2. An electric vehicle control device comprising a motor having a shunt coil in a battery field, a motor rotation detector, an accelerator having an electric signal, a brake switch, and a motor control device having a microcomputer capable of running and regenerating. In the above, in the circuit for controlling the shunt coil current by the transistor bridge, the capacitor is charged from the chopper transistor via the diode transistor, and this voltage is used as the power source for the base current control of the transistor for switching the transistor bridge. Control unit for electric vehicles.