JPS6227601B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric vehicle control device, and more particularly to an electric vehicle control device having detection means for detecting an abnormality in an electromagnetic contactor and a chopper circuit that control the energization of an electric motor.

A conventional power supply, a contactor, a motor, and a control circuit are connected in series, and the power supplied to the motor is controlled by the control circuit, and in the event that the control circuit becomes uncontrollable, the contactor is opened. In the electric vehicle control device configured to prevent the electric vehicle from running out of control, there is no means for detecting welding of the contactor.

For this reason, in an electric vehicle control device with a conventional configuration, if the contactor that connects the power source and the electric motor is welded and the control circuit that controls the power supplied to the electric motor becomes uncontrollable, the contactor is It is extremely dangerous because it cannot be opened to prevent the electric car from running out of control.

In order to solve the above-mentioned drawbacks, the present invention detects whether or not the contactor that connects the power source and the motor is welded when starting an electric vehicle, and if the contactor is welded,
The object of the present invention is to provide an electric vehicle control device that can safely protect the electric vehicle by prohibiting the operation of the control circuit that controls the power supply to the electric motor, and by opening the contactor in the event of an abnormality in the control circuit. That is.

FIG. 1 shows an electrical wiring diagram of a first embodiment of the present invention.

In Figure 1 electrical circuit diagram, 1 is a DC power supply, 2
3 is a control circuit for controlling the power supplied to the electric motor 2, such as a thyristor chopper circuit (hereinafter referred to as chopper); 4 is an electromagnetic contactor as a contactor; and 5 is an electromagnetic contactor. Its excitation winding, 6
7 is a start switch, which is turned on when the accelerator (not shown) is depressed, and 7 is a flywheel diode. 8 is a diode,
10 is a comparator, 16 and 17 are voltage dividing resistors that provide an inverting input of the comparator 10, and 18 and 19 are voltage dividing resistors that provide a non-inverting input of the comparator 10, and these are used to open and close the contacts of the magnetic contactor 4. A first detection circuit is configured to detect. 9 is a diode, 20 is a resistor, 1
5 is a capacitor, 29 is a resistor, and comparator 10
A charging circuit is configured to be charged according to the output of the
11 is a comparator, 21 and 28 are voltage dividing resistors that provide non-inverting inputs of the comparator 11, and constitute a second detection circuit. 12 is a switching transistor;
23 is its base resistance, 24 is its collector resistance, and 22 is a feedback resistance for feeding back the collector output of the transistor 12 to the inverting input of the comparator 11.
13 is a switching transistor for energizing the excitation winding 5, and 26 is its base resistance. 14 is a switching transistor for controlling the output of the trigger circuit 50, and 25 is its base resistance.

The operation of the above configuration will be explained.

Note that since the operations of the chopper 3 and the trigger circuit 50 are already known, a description of the operations will be omitted.

Press accelerator switch 6 to start the electric car.
When turned on, a voltage is applied to the non-inverting input terminal (hereinafter referred to as the (+) input terminal) of the comparator 10 via the resistor 27. On the other hand, since the contactor 4 is not closed, no voltage is applied to the inverting input terminal (hereinafter referred to as the (-) input terminal) of the comparator 10. As a result, a voltage is generated at the output of the comparator 10 (hereinafter referred to as output 1), and charging of the capacitor 15 via the diode 9 and the resistor 20 begins with this output. Here, a voltage is applied to the (+) input terminal of the other comparator 11 at the same time as the accelerator switch 6 is turned on.
Since no voltage is applied to the (-) input terminal, the output of comparator 11 is 1. As a result, transistors 12 and 14 are turned on, respectively turning off transistor 13 and cutting off signals from trigger circuit 50 and chopper 3. Therefore, during the period when the output of the comparator 11 is 1, the transistor 13 is not turned on, so the contactor 4 is not turned on, and the chopper 3 is not operated because the trigger signal is not supplied. When a predetermined period of time elapses after the accelerator switch 6 is turned on, the charging voltage of the capacitor 15 rises, and the output of the comparator 11 turns on (hereinafter referred to as output 0), turning off the transistors 12 and 14. As a result, the transistor 13 is turned on, the contactor 4 is turned on, and a trigger signal is supplied to the chopper 3, so that the chopper 3 starts controlling the power supply to the motor 2. On the other hand, the transistor 12
Since the capacitor 15 is charged via the resistor 22 due to the OFF state, once the output of the comparator 11 becomes 0, the output continues to be 0.

Next, a case where the contactor 4 is closed for some reason when the accelerator switch 6 is turned on will be explained. Since the contactor 4 is already closed when the accelerator switch 6 is turned on, the output of the comparator 10 continues to be 0. As a result, the capacitor 15 is not charged, so the output of the comparator 11 is 1. Therefore, transistor 14 continues to be ON, so chipper 3
is not supplied with a trigger signal.

A second embodiment of the device of the present invention will be explained with reference to FIG. Comparator 1 is structurally different from the first embodiment.
0 output is provided with voltage dividing resistors 30, 31 and a transistor 32, and the output of the comparator 10 is provided with a diode 33 at the input end of the chopper circuit 3 to bypass the output.

The operation of the above configuration will be explained. Furthermore, the second
Components in the figure with the same reference numerals as in FIG. 1 operate in the same way, so their explanation will be omitted. transistor 32
is turned on during the period of output 1 of the comparator 10, that is, the period from when the accelerator switch 6 is turned on until the contactor 4 is closed, and the trigger signal is cut off. As a result, the chopper 3 is supplied with a trigger signal and starts operating after the contactor 4 is turned on. On the other hand, the cathode of the diode 33 is connected to the side terminal of the chopper. As a result, if the chopper 3 turns on for some reason or the impedance drops unduly while the capacitor 15 is being charged by the output 1 of the comparator 10, the charging current of the capacitor 15 is bypassed to the chopper 3 via the diode 33. be done. As a result, the output of the comparator 11 cannot be reversed from 1 to 0, so the contactor 4 is not turned on.

In the above description, the comparators 10 and 11 are constructed using operational amplifiers, but they can operate in the same manner even if they are constructed using other circuit means, such as transistors.

In order to inhibit the operation of the chopper 3 during the output 1 period of the comparators 10 and 11, the transistor 3 is
2 and 14 are used to cut off the trigger signal, however, the operation will be the same even if the operation of the chopper 3 is prohibited by prohibiting the operation of the oscillation circuit or the differential circuit constituting the trigger circuit.

Although the accelerator switch 6 is used as the starting switch, a series switch circuit such as a key switch or a brake switch may also be used as the starting switch.

Although we have explained using an electromagnetic contactor as a contactor, it is possible to use two electromagnetic contactors, which are already known for controlling battery forklifts, etc., and reverse the connection of the motor's field or armature to operate the motor. Even if it is configured to have both the function of a reversing device for reverse rotation and the function of connecting the power source and electric motor described in the present invention, it will operate in the same way.

As described above, the device of the present invention is configured to detect the state of the contactor that connects the power source and the motor when starting the electric vehicle, and to prohibit the operation of the control circuit if the contactor is welded. Therefore, it has the excellent effect of preventing the electric vehicle from running out of control in the event of an abnormality in the control circuit.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram showing a first embodiment of a control device according to the present invention, and FIG. 2 is an electric circuit diagram showing a second embodiment of the control device according to the present invention. 2...Electric motor, 3...Chopper circuit, 4...Contactor, 10...Comparator, 11...Comparator, 33...
...Diode, 50...Chopper control circuit.

Claims (1)

[Claims] 1. In a control device for an electric vehicle in which the contacts of a magnetic contactor, a motor and a chopper circuit, and a starting switch and a chopper control circuit are each connected in series with a power source, the electromagnetic contactor is turned on after a predetermined period of time has elapsed after the starting switch is turned on. The power supply is supplied to the chopper control circuit which closes the contacts of the chipper and supplies a control signal to the chopper circuit, and on the other hand, in the case of a failure in which the contacts of the electromagnetic contactor are closed before the start switch is turned on, Control of an electric vehicle, comprising a detection circuit that substantially cuts off the control signal supplied from the tipper control circuit to the tipper circuit, and opens a contact of the electromagnetic contactor when the tipper circuit is abnormal. Device.