JPH02269402A - Controller for electric vehicle - Google Patents

Abstract

PURPOSE:To prevent loss of a breaker and occurrence of breaking impossibility by providing a voltage comparator for comparing a motor voltage with a set value, and control means for releasing the breaker by a single from the comparator. CONSTITUTION:When a generated voltage of a vehicle upon reduction of a regenerative current reaches a conduction set value of an overvoltage suppressing thyristor 16, the thyristor 16 conducts to reduce the generated voltage, but a main motor is regeneratively controlled from the load of a series resistor 17 connected in series with the thyristor 16. In this case, breakers 6A, 7, 8 are opened when the generated voltage of the motor is sufficiently reduced by a voltage comparator 132 and a logic circuit 151. Thus, the loss of the breakers 6A, 7, 8 and the breaking impossibility thereof can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electric vehicle control device that controls a DC motor provided in a voltage vehicle, and particularly to an electric vehicle control device that suppresses overvoltage.

[Conventional technology]

As a means for suppressing overvoltage of the motor voltage applied to a DC motor installed in an electric car, Japanese Patent Application Laid-Open No. 55-237
As described in Publication No. 1, a chopper and an overvoltage suppression thyristor are provided in the motor circuit, and when an overvoltage is detected, the thyristor is made conductive and a resistor is inserted in the circuit to reduce the current flow rate of the chopper. Proposals for suppressing this are known.

[Problem to be solved by the invention]

However, according to the above-mentioned conventional technology, if the resistance value of the resistor inserted into the circuit is small enough, it can absorb the energy of the motor, but if the resistance value is made small, the flowing current increases, so the capacitance of the resistor and thyristor is reduced. must increase.

One possible way to prevent this increase in capacity is to reduce the voltage generated by the motor by controlling the current flow rate of the chopper, but in the case of a field chopper, the time constant of the field circuit is large, so the chopper Even if the conduction rate is controlled, the voltage generated by the motor cannot be suddenly reduced. Therefore, the circuit breaker for opening the circuit will break at a high voltage, which may cause damage to the circuit breaker or break the circuit breaker. There was a risk that it would become impossible.

Furthermore, when the resistance value of the resistor is reduced, the current flowing through the circuit becomes large, and a similar problem occurs in a circuit breaker.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electric vehicle control device that can prevent a circuit breaker provided in an electric motor circuit from becoming damaged or unable to shut off. shall be.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a DC motor,
It consists of a chopper that controls the current flowing through the separately excited field winding of this DC motor, a voltage detector that detects the motor voltage, a thyristor that suppresses overvoltage of this motor voltage, and a circuit breaker that opens the motor circuit. The electric vehicle control device is provided with a voltage comparator that compares the motor voltage with a set value, and a control means that opens the circuit breaker based on a signal from the voltage comparator.

[Effect]

According to the above configuration, after the overvoltage suppression thyristor conducts and the voltage comparator confirms that the voltage generated by the motor has decreased, the circuit opening circuit breaker is opened via the control means by the signal emitted from the voltage comparator. Extreme. Therefore, it is possible to prevent the circuit breaker from being damaged or unable to shut off.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an electric vehicle control device according to the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. The figure shows two electric cars, car A is labeled with the symbol A, and car B is labeled with the symbol B. Next, a case where vehicle A is performing regenerative braking control with vehicle B as a load will be described.

In the figure, 1 is an overhead contact line and 2 is a pantograph. The pantograph 2 has armature circuit breakers 6A and 7, an armature 3A of the main motor, and a series field winding 4A connected in series, and the winding 4A is connected to the ground 18A. A separately excited field circuit is connected in parallel to this main motor circuit, and a separately excited field circuit breaker 8. Separately excited field winding 5 and a chopper 9 that controls the current of this winding 5
are installed in series. Further, a flywheel diode 10 is connected in parallel to the separately excited field winding 5 for circulating the separately excited field winding current when the chopper 9 is in an off state. A voltage detector 11 and voltage comparators 131 and 132 for detecting the voltage of the main motor are connected to the main motor circuit.

A relay circuit 141 is further connected to these voltage comparators 131 and 132 for demagnetizing the operating coil 61 of the circuit breaker 6A using the outputs of the comparators. Further, a theoretical circuit 151 is connected to this relay circuit 141,
This theoretical circuit 151 has the function of demagnetizing the operating coil 71 of the circuit breaker 7 using its output and the output of the voltage comparator 132. Furthermore, the main motor circuit has voltage comparators 131 and 132.
An overvoltage suppressing thyristor 16 is provided in parallel, which becomes conductive in the event of an overvoltage due to the output of the thyristor 16, and a series resistor 17 is connected in series with the thyristor 16. Note that code 1
9 is ground.

Next, the operation of this embodiment will be explained. It is known that when the voltage of the main motor circuit is lower than the conduction setting value of the overvoltage suppression thyristor 16, control is performed to narrow down the separately excited field current using the chopper 9. Here, the cause of a high voltage exceeding the conduction setting value of the overvoltage suppressing thyristor 16 is when the regenerative load disappears during one regeneration, and the chopper 9 that controls the separately excited field current acts to narrow down the current. However, due to the inductance of the separately excited field winding 5, the reduction time constant of the field current becomes long, and the field current cannot be narrowed down sufficiently.

Figure 2 shows the generated voltage of car A when the regenerative load of car A is cut off due to car B notching off, etc. In Fig. 2, as the regenerative current I decreases, the generated voltage E of car A decreases.
When Q reaches the conduction set value EQ8 of the overvoltage suppression thyristor 16, the overvoltage suppression thyristor 16 becomes conductive and the generated voltage EQ is lowered, but the main motor is The balance voltage at this time for performing regeneration control is E Q'z. At this time, in reality, as shown by the dashed line in FIG. 2, the generated voltage is suppressed to EQs by the throttling action of the chopper 9, but if the voltage comparator 132 and logic circuit 151 shown in FIG. .

Since the circuit breaker 7 is opened at the voltage of EQ4, the circuit breaker is likely to be damaged or unable to shut off.

However, by providing a voltage comparator 132 and a logic circuit 151 as shown in FIG. It is possible to prevent the occurrence of damage or failure to shut off.

〔Effect of the invention〕

As explained above, according to the present invention, the circuit breaker is opened only after the voltage and current of the DC motor circuit installed in the electric car become sufficiently small. It is possible to prevent the occurrence of damage or failure to shut off.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the electric vehicle control device according to the present invention, and FIG. 2 is a graph showing the regenerative current and generated voltage of the main motor when overvoltage occurs. 5... Separately excited field winding, 6, 7.8... Circuit breaker, 9.
...Chopper, 11...Voltage detector, 16...Thyristor, 131.132...Voltage comparator, 141...
- Relay circuit (control means), 151... logic circuit (control means). 2nd

Claims (1)

[Claims] 1. A DC motor, a chopper that controls the current flowing to the externally excited field winding of this DC motor, a voltage detector that detects the motor voltage, a thyristor that suppresses overvoltage of this motor voltage, and a motor circuit that opens. A voltage vehicle control device comprising a circuit breaker, comprising: a voltage comparator for comparing the motor voltage with a set value; and a control means for opening the circuit breaker in response to a signal from the voltage comparator. Characteristic electric vehicle control device.