JPH08214403A - Driving controller for electric vehicle - Google Patents

Abstract

PURPOSE: To improve safety by making possible movement at a small distance by using the residual power of a battery for emergency shunting even at the time of the stoppage of an electric vehicle by the lowering of battery voltage. CONSTITUTION: The driving of a motor is controlled by controlling battery power fed to the motor 14 by a motor driving control section 15 at the time of normalcy when battery voltage monitored by a battery monitor section 13 is not lowered up to a threshold or less, and an electric vehicle is made to travel. When battery voltage is lowered until it is made to lower than the threshold and a stoppage command is output from the battery monitor section 13 and motor driving is stopped, an emergency driving command is transmitted to the motor driving control section 15 by closing a switch 16 for emergency, and emergency shunting and movement are made possible by small power remaining until a battery 11 is emptied completely. Accordingly, even when the battery is discharged up to stoppage voltage by any reason and the electric rolling stock is stopped at a dangerous place, the electric vehicle can be shunted for emergency and move by itself up to a safe place.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control device for an electric vehicle, and more particularly to a drive control device for an electric vehicle having an emergency escape function when the voltage of a main battery drops.

[0002]

2. Description of the Related Art Generally, in an electric vehicle, as shown in FIG. 8, a main battery 1 having a high voltage output exceeding 300 V is used as a drive source, and the drive motor 2 is driven by the main battery 1 to drive the vehicle. An auxiliary battery 3 having a low voltage output of about 12V is mounted for various electric circuits and lighting. In order to charge the auxiliary battery 3 at all times, the DC / DC converter 4 steps down the power of the main battery 1 to convert it to a desired low-voltage power and supplies the low-voltage power to the auxiliary circuit. I am trying to charge.

By the way, as a characteristic of the secondary battery, the life of the main battery becomes extremely short when it is used from a fully charged state to a completely empty state, that is, an over-discharged state. 80 of fully charged power
When used up to about%, the remaining capacity meter is set to display empty to prompt recharging, and if the vehicle is still driven, a predetermined threshold value V as shown in FIG.
It has a function of stopping the drive motor when the voltage drops before the value of th is cut.

[0004]

However, in such a conventional drive control device for an electric vehicle, the main battery voltage drops to a stop voltage and suddenly stops due to a driver's carelessness or reckless driving. If the place you have left is inside a railroad crossing or in the middle of a road, you must evacuate and move from that place to a safe place for traffic safety, but drive until the threshold voltage Vth is cut. If the vehicle stops after that, no further measures are taken so that the vehicle can be moved by itself, and it has been desired to add some function to make an emergency escape.

The present invention has been made in view of the above-described conventional technical problems, and enables the vehicle to move a small distance by itself for emergency escape even after the battery voltage has dropped to the stop voltage. Therefore, it is an object of the present invention to provide a drive control device for an electric vehicle with improved safety.

[0006]

According to another aspect of the present invention, there is provided a drive control device for an electric vehicle, comprising: a motor drive control section for controlling the drive of the drive motor by controlling battery power supplied to the drive motor. , Monitor the battery voltage,
The battery monitoring unit that outputs an output stop command to the motor drive control unit when the voltage drops by the time the threshold value is crossed and the predetermined threshold value is compared, and the motor And an emergency switch for giving an emergency drive command to the drive control unit.

According to another aspect of the present invention, there is provided a drive control device for an electric vehicle, a drive motor for driving the electric vehicle, a high voltage output main battery for supplying electric power to the drive motor, and an auxiliary for the electric vehicle. Equipped with a low-voltage output auxiliary battery for supplying power to the circuit, and a reversible conversion function that steps down the high-voltage input to convert it to the desired low-voltage output and boosts the low-voltage input to convert it back to the predetermined high-voltage output. Connect the DC / DC converter and the high voltage input side of the DC / DC converter to the main battery during normal operation, connect the low voltage output side to the auxiliary battery, and connect the low voltage input side of the DC / DC converter to the auxiliary battery in an emergency. , An emergency switch for disconnecting the high-voltage output side from the main battery and connecting it to the drive motor.

[0008]

According to another aspect of the present invention, in the drive control device for an electric vehicle, the battery supplied to the drive motor by the motor drive control unit is normal when the battery voltage monitored by the battery monitoring unit does not drop until it falls below a threshold value. The drive of the drive motor is controlled by controlling the electric power to drive the vehicle.

Then, the battery voltage drops until it falls below the threshold value, and a stop command is output from the battery monitoring unit.
When the motor drive is stopped, the emergency drive command is given to the motor drive controller by turning on the emergency switch.
It enables emergency evacuation and movement with a little electric power remaining until the battery is completely empty.

Thus, even if the battery is discharged to the stop voltage for some reason and stopped at a dangerous place, it is possible to evacuate and move to a safe place by itself. Therefore, the safety can be improved.

In the drive control device for an electric vehicle according to the second aspect of the present invention, during normal operation, the electric power of the main battery is used to drive and control the drive motor to drive the vehicle.

In the case where the main battery has dropped to the stop voltage and stopped at a dangerous place, and it becomes necessary to evacuate or move to a safe place,
By operating the emergency switch, the power of the low-voltage output auxiliary battery, which is almost fully charged, is inversely converted by the DC / DC converter having the inverse conversion function to be boosted and supplied to the drive motor. Allows emergency evacuation and movement.

Thus, even if the battery is discharged to the stop voltage for some reason and stopped at a dangerous place, the auxiliary battery can be used for emergency evacuation and movement to a safe place. To be able to
The safety can be improved.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a functional block diagram of an embodiment of the invention of claim 1, in which the voltage of the main battery 11 of high voltage output,
A voltage / current detection unit 12 that detects a current, a battery monitoring unit 13 that monitors whether or not the battery voltage has dropped by a threshold value, and power of the main battery 11 are supplied to the drive motor 14. And a motor drive control unit 15 for driving the vehicle.

In the drive control device of this embodiment, the emergency switch 16 which gives a drive command in an emergency and the battery monitor 13 outputs a stop command.
And an AND circuit 17 for giving a drive command to the motor drive control unit 15 when is turned on. The emergency switch 16 is realized by, for example, turning on the starter switch in the direction opposite to the normal start operation direction, or by separately installing a dedicated push button switch or knob switch in the driver's seat. To be done.

Next, the operation of the drive control device for the electric vehicle having the above structure will be described with reference to the flowchart of FIG. The voltage / current detector 12 detects the voltage and current of the battery 11 and inputs them to the battery monitor 13 (step S1).

The battery monitoring unit 13 monitors the input battery voltage and current, integrates the battery current to obtain the discharge amount, and subtracts the discharge amount from the full charge capacity to determine the remaining capacity with respect to the fully charged capacity. The battery remaining capacity indicator (not shown) is used to display the level on the full F-empty E scale as in the case of a normal fuel meter, and the processing shown to the driver is performed. At the same time, the battery monitoring unit 13 monitors whether or not the battery voltage V has dropped by the time the voltage threshold Vth is exceeded, as shown in FIG. 3A (step S2).

Therefore, the battery voltage V becomes the voltage threshold value Vt.
While not decreasing to h, the normal operation mode is set, the motor drive command is output to the motor drive control unit 15, and the motor drive control unit 15 uses the battery power as a drive source and outputs the drive motor 14 according to the torque command from the accelerator pedal. Is driven (step S3).

When the operation in the normal operation mode is continued and eventually the battery voltage V drops below the voltage threshold Vth, the battery monitoring unit 13 causes the emergency switch 16 to operate.
Unless is input, the output of the drive command to the motor drive control unit 15 is stopped, and the motor drive control unit 15 stops the drive control of the drive motor 14 (steps S2, S4, S
5).

When the battery voltage V drops below the threshold value Vth and the driving motor 14 is stopped, the vehicle stops inside the railroad crossing and it is necessary to evacuate the railroad crossing urgently. When there is a need to move to the roadside urgently by stopping in the middle of the road, the driver turns on the emergency switch 16 (step S4).

By turning on the emergency switch 16,
While the switch is turned on, the ON signal is input to the AND circuit 17, while the drive command from the battery monitoring unit 13 is OFF, the ON signal is input as its inverted signal,
The drive command is input to the motor drive control unit 15 as the output of the AND circuit 17, and the motor drive control unit 15
Drives the drive motor 14 by the last electric power of the battery 11 which has run low, and causes the vehicle to move urgently (step S6).

That is, the battery is used as shown in FIG. 3 (a) when it is new, during intermediate use, and at the end of its life.
Shows voltage-current characteristics C1, C2, C3 as shown in
The operation is stopped when the threshold value Vth is reached,
In order to avoid over-discharging, at any time, as shown in the figure (b), the capacity W1, W2, W
Only 3 are left. Therefore, this remaining capacity W1, W2
The drive motor 14 is driven by using W3 so that the vehicle can be moved urgently for a short distance.

As described above, in the drive control device for the electric vehicle of this embodiment, the battery voltage drops until it falls below the threshold value, and the vehicle stops. If you were in the middle of, emergency evacuation,
The last remaining capacity of the battery is used by operating the emergency switch because it needs to be moved (in this case, it is for emergency measures, so do not consider shortening the battery life due to over discharge) , While driving the emergency switch, the drive motor can be driven to safely exit the railroad crossing or move to the roadside, improving safety.

Next, an embodiment of the invention of claim 2 will be described with reference to FIGS. As shown in FIG. 4, the drive control device for an electric vehicle of this embodiment, together with a high-voltage output main battery 21 that drives the drive motor 20, is constantly charged by the main battery 21 so that an electric circuit, a lighting circuit, etc. It is equipped with a low-voltage auxiliary battery 22 as an auxiliary power source for supplying power to the auxiliary circuit,
Further, a DC / DC converter 23 for charging the auxiliary battery 22 while reducing the high-voltage power of the main battery 21 to convert it to low-voltage power to supply power to the auxiliary circuit is provided.

The DC / DC converter 23 is capable of switching between conversion of high-voltage input and low-voltage output and conversion of low-voltage input-high-voltage output, which is the reverse conversion thereof.
A transformer section B and a rectifying / smoothing section C. The transformer section B is provided with a direction changeover switch SW1 for switching between the input switching section A and the rectifying / smoothing section C in a step-up direction or a step-down direction. There is.

At the input end a of the input switching section A of the DC / DC converter 23, a battery switch SW for switching the connection between the main battery 21 and the auxiliary battery 22.
2 is provided, and the auxiliary battery 22 and the drive motor 20 are provided at the output end c of the rectifying / smoothing unit C of the DC / DC converter 23.
An output destination changeover switch SW3 for switching connection between and is provided.

These changeover switches SW1 to SW3 perform a changeover operation in conjunction with each other, and in the normal operation mode, the connection state shown in FIG. 5, that is, the main battery 21-the input switching section A-the transformer section B of the DC / DC converter 23. Winding T1: Step-down: Winding T of transformer B2-Rectifying and smoothing C-
The auxiliary battery 22 is connected. And the changeover switch S
By switching W1 to SW3 all at once, the connection state shown in FIG. 6, that is, the winding T2 of the auxiliary battery 22-the input switching unit A of the DC / DC converter 23-the transformer unit B: boosting: winding T1-rectification smoothing Section C-The drive motor 20 is connected.

Next, the operation of the drive control device for the electric vehicle having the above configuration will be described with reference to the flowchart of FIG. The voltage of the main battery 21 is constantly monitored, and the normal operation mode is maintained when the voltage does not drop until the preset stop voltage is cut off (steps S11 and S12).

At this time, the changeover switches SW1 to SW3 are in the connected state shown in FIG. 5, and the high voltage power of the main battery 21 is supplied to the drive motor 20 to drive the vehicle. At the same time, the high-voltage power of the main battery 21 is supplied to the DC / DC converter 23, which is stepped down and converted into a predetermined low-voltage power to charge the auxiliary battery 22, and an auxiliary power supply circuit such as an electric circuit or an illumination lamp (see FIG. (Not shown).

When the voltage of the main battery 21 falls below a predetermined stop voltage during operation in the normal operation mode, the main battery 21 is forcibly disconnected from the drive motor 20 and the drive of the vehicle is stopped. As a result, wherever the vehicle is, it will stop there. Therefore, if the stopped place is a safe place, it is stopped and the main battery 21 is charged by some method (steps S11, S13, S14).

However, if the stopped place is a dangerous place such as a railroad crossing or the middle of a road, it is necessary to move urgently. In such a case, the main battery 21
Can no longer be used as the power source of the drive motor 20, so the changeover switches SW1 to SW3 are changed all at once.

When the changeover switches SW1 to SW3 are changed over, the connection state shown in FIG.
Completely disconnected from the C / DC converter 23 and DC /
The output of the DC converter 23 does not flow into the main battery 21 (steps S13 and S15). Then, the auxiliary battery 22 which has been kept fully charged by the main battery 21 is connected to the input switching unit A of the DC / DC converter 23, and the transformer unit B is switched in the boosting direction, so that the auxiliary battery of low voltage output is provided. The output of 22 is step-up converted by the DC / DC converter 23, and the high-voltage output is supplied to the drive motor 20 to be driven, so that the vehicle can be evacuated and moved to a safe place for a short distance. (Step S
16-S19).

As described above, in the drive control device for the electric vehicle of this embodiment, the main battery 2 is operated during the normal operation.
Although the driving motor 20 is driven by the electric power of 1, the DC / DC converter 23 is step-up converted by the switching operation of the changeover switches SW1 to SW3 when the voltage of the main battery 21 falls below the stop voltage and the vehicle cannot run. And the auxiliary battery 22 is used as a power source.
C / DC converter 23 boosts the voltage and converts it to drive motor 2
Even if the place where it stopped due to the voltage drop of the main battery 21 was inside the railroad crossing or in the middle of the road, it was possible to safely escape from it. , It can be moved to the roadside, improving safety.

[0034]

As described above, according to the invention of claim 1,
When the battery voltage drops below the threshold value and the battery monitoring unit outputs a stop command, and when the motor drive is stopped, the emergency drive command is given to the motor drive control unit by turning on the emergency switch, Emergency evacuation on your own with a little electric power remaining until is empty,
Since it is possible to move, even if for some reason the battery is discharged to the stop voltage and it stops at a dangerous place, it will be possible to evacuate and move to a safe place, The safety can be improved.

According to the second aspect of the present invention, in the case where the main battery has dropped to the stop voltage and stopped at a dangerous place, it becomes necessary to evacuate or move to a safe place. By operating the emergency switch, the power of the low-voltage auxiliary battery, which is almost fully charged, is inversely converted by the DC / DC converter having the inverse conversion function to be boosted and supplied to the drive motor. Emergency evacuation,
Since it is possible to move, if for some reason the main battery is discharged to the stop voltage and it stops in a dangerous place, use the auxiliary battery for emergency evacuation and movement to a safe place. It becomes possible to improve the safety.

[Brief description of drawings]

FIG. 1 is a circuit block diagram of an embodiment of the invention of claim 1;

FIG. 2 is a flowchart of the drive control operation of the above embodiment.

FIG. 3 is a graph illustrating the operating characteristics of the above embodiment.

FIG. 4 is a circuit block diagram of an embodiment of the invention of claim 2;

FIG. 5 is a block diagram showing a circuit state during normal operation of the above embodiment.

FIG. 6 is a block diagram showing a circuit state at the time of emergency operation of the above embodiment.

FIG. 7 is a flowchart of the drive control operation of the above embodiment.

FIG. 8 is a circuit block diagram of a conventional example.

[Explanation of symbols]

 11 Battery 12 Voltage / Current Detection Section 13 Battery Monitoring Section 14 Drive Motor 15 Motor Drive Control Section 16 Emergency Switch 17 AND Circuit 20 Drive Motor 21 Main Battery 22 Auxiliary Battery 23 DC / DC Converter SW1 Direction Change Switch SW2 Battery Change Switch SW3 Output destination changeover switch A Input switching block B Transformer block C Rectifying and smoothing block

Claims (2)

[Claims] 1. A motor drive control unit that controls the drive of the drive motor by controlling the battery power supplied to the drive motor, and the battery voltage is monitored and compared with a predetermined threshold value. A battery monitoring unit that outputs an output stop command to the motor drive control unit when the voltage drops before the threshold value is cut, and an emergency drive command to the motor drive control unit when the stop command is output from the battery monitoring unit. And an emergency switch for providing an electric vehicle drive control device. 2. A drive motor for driving an electric vehicle, a high voltage output main battery for supplying electric power to the drive motor, and a low voltage output auxiliary for supplying electric power to an auxiliary circuit of the electric vehicle. A battery, a DC / DC converter having a reversible conversion function for stepping down a high-voltage input to convert it to a desired low-voltage output, and boosting a low-voltage input to inversely convert it to a predetermined high-voltage output; The high voltage input side of the DC converter is connected to the main battery, the low voltage output side is connected to the auxiliary battery, the low voltage input side of the DC / DC converter is connected to the auxiliary battery, and the high voltage output side is connected to the main battery. A drive control device for an electric vehicle, comprising: an emergency switch that is disconnected from a battery and connected to the drive motor.