JPS5829301A - Controlling circuit for regenerative brake equipment for electric rolling stock - Google Patents

Abstract

PURPOSE:To obtain an excellent braking characteristics by changing a motor braking torque to be linear in accordance with the revolving speed of a motor. CONSTITUTION:When an acceleration switch is turned ON, a power mode instruction is delivered by a mode switching circuit 14, thereby a main contactor 5 and field relays 7 and 9 are closed onto the side (b) and the sides a1 and b2 respectively, and according to the output of an accelerating device 16, a conduction ratio instruction is delivered to an armature chopper 3 and a field chopper 12 by a power controlling circuit 15. When a brake switch is turned ON, a regeneration mode instruction is delivered by the mode switching circuit 14, and thereby the main contactor 5 and the field relays 7 and 9 are closed onto the side (a) and the sides b1 and a2 respectively. A field current instruction is delivered through a regeneration controlling circuit 13 according to the output of a motor revolving-speed detector 11, and a conduction ratio instruction is given to a field chopper 12. Meanwhile, a conduction ratio instruction is given to an armature chopper 3 so that an armature current becomes constant.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a regenerative braking control circuit for an electric vehicle, and more particularly to a regenerative braking control circuit that controls the braking torque of a vehicle to be constant.

Conventionally, in regenerative braking for electric vehicles, it has been common to control the field current to be constant and the armature current to be constant as well. However, in the case of a 1-minute winding motor, the motor voltage increases in proportion to the field current at high speeds.

In the chopper boost type circuit, there was a problem that the rise of the armature current was large, the armature current became large, and the motor current failed or the braking force increased.To solve this problem, the motor voltage was detected, Improvement measures have been taken, such as weakening the field current when the motor voltage exceeds a certain value. recently,
Driving sensation due to braking force has become an issue, and it has been thought that a constant deceleration regardless of vehicle speed is optimal. In that case, it is necessary to consider the braking force due to running resistance, and it is necessary to control the braking torque of the electric motor according to the vehicle speed.

For example, at a vehicle speed of 7 Q km/h, the running load torque is approximately twice that of a low speed, and cannot be ignored as a braking torque.

An object of the present invention is to provide a regenerative braking control circuit for electric vehicles that has good braking force characteristics.

The present invention achieves good control by linearly changing the motor braking torque according to the motor rotation speed, and using an operational amplifier to linearly reduce the field current command when the field current command exceeds a certain value compared to a predetermined level. Even though I tried to give it some power characteristics,
So there is 1.

Examples of the present invention will be described below.

FIG. 1 shows an embodiment of the invention.

In the figure, 1 is the main battery, 2 is the fuse breaker,
3 is the armature chopper, 4 is the freewheel diode,
5 is the main contactor, 6 is the motor armature, 7 is the field relay, 8 is the field coil, 9 is the field relay, and 10 is the freewheel diode.

11 is a rotation detector, 12 is a field chopper, 3 is a regeneration control circuit, 14 is a mode switching circuit, 15 is a row control circuit,
16 is an accelerator device, 17 and 18 are current detectors, and 19 is a comparator.

Now, when the accelerator switch is turned on, the mode switching circuit 14 issues a row mode command.

The main contactor 5 closes to the contact side, and the field relay (1) 7
moves to the a side, the field relay (2) 9 closes to the a side, and according to the output of the accelerator device 16, the flow control circuit 15 issues a conduction rate command to the armature chopper 3 and the field chopper 12. ing.

Current detectors 17 and 18 are for controlling current.

When the brake switch is turned on, a regeneration mode command is issued by the mode switching circuit, the contact of the main contactor 5 closes to the a side, field relay (1) 7 closes to the b1 side, and the field relay (2) closes to the b1 side. 9 closes to the side a. With such a main circuit configuration, the field current command is output through the 1st regeneration control circuit 13 according to the output of the motor rotation speed detector 11, and the 0 armature chopper outputs the duty ratio command to the field chopper 12. 3
A conduction rate command is given to keep the armature current constant.

Freewheel diodes 4 and 10 are for circulation.

In addition, when the engine is over-rotated, comparators 1 and 9 output a lock signal so that the regeneration mode is selected from the power mode.

FIG. 2 shows a specific circuit of the regeneration control circuit 13 of the embodiment shown in FIG. Rotation detector 11 shown in Figure 1
The signal is input to point A in FIG. 2, smoothed by Tycho R1 and capacitor C1, and input to the inverting input of operational amplifier OP. In the operational amplifier OP, compared to the level of the non-inverting input.

The output of the operational amplifier OP is output in proportion to the number of rotations.The third □□□ also includes an armature current command 1 for the number of rotations of the motor. The relationship between the field current command I and the field current command I is shown.

In Fig. 3, the reason why I is small below N□ is to reduce the torque command at low speeds and soften the shock when regeneration stops. This is because regenerative braking is regenerated with direct current. Furthermore, the reason I was strengthened in NII was to prevent over-speeding, and even in this case, power is regenerated to the power supply using DC. Figure 4 shows the motor rotation speed when regenerative braking is stopped at low speeds. Field current command F and armature current command I for
The relationship between

Therefore, according to this embodiment, the braking torque can be controlled to be substantially constant, and the driving sensation can be greatly improved.

Further, according to this embodiment, the current control at high speed is stable because the field current command is small, and the control device can be made small and inexpensive.

According to this embodiment, over-rotation prevention control of the motor can also be realized without adding a detector.

Furthermore, according to this embodiment, in a device that performs regenerative braking equivalent to engine braking, it is possible to stop using regenerative braking at low speed.
It can reduce the shock when stopping.

As explained above, according to the present invention, good braking characteristics can be obtained.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, FIG. 2 is a regeneration control circuit diagram shown in FIG. 1, and FIG. 3 is a control characteristic diagram of this embodiment.
FIG. 4 is a regenerative braking characteristic diagram at low speeds.

Claims (1)

[Claims] 1. In a regenerative braking control circuit for an electric vehicle that regenerates power from a shunt motor to the main power source, a first means for controlling armature current using an armature current command, and a first means for controlling field current using a field current command. a fourth means for providing a field current command to the second means according to a function of the rotation speed signal from the third means;
A regenerative braking control circuit for an electric vehicle, characterized in that it comprises means for providing a constant value as an armature current command to the first means.