JPH08214409A - Power supply device for electric vehicle - Google Patents

Abstract

PURPOSE: To provide a power supply device for an electric vehicle capable of sufficiently making the vehicle reach up to a safe place or a maintainable place by continuing the operation of auxiliary machines for a period as long as possible and lengthening a travel distance even when a battery power supply for auxiliary machines cannot be charged. CONSTITUTION: A motor 4 for travelling is driven by the voltage of a battery power supply 1 for travelling, auxiliary machines 7 are operated by the voltage of a battery power supply 6 for auxiliary machines, and the voltage of the battery power supply 1 is lowered by a DC/DC converter 5 and the battery power supply 6 is charged. When abnormality is generated in the DC/DC converter 5, the abnormality is detected by a current sensor 8 and an abnormality detecting section 10, and the battery power supply 6 is directly coupled with a battery as a part of the battery power supply 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for an electric vehicle that runs on the power of a motor.

[0002]

2. Description of the Related Art An electric vehicle equipped with a traveling motor instead of an engine has been developed and put into practical use. This electric vehicle includes a traveling battery power source that outputs drive power to a traveling motor. This battery power source for traveling is, for example, one in which a plurality of batteries are connected in series,
It outputs the high voltage of several hundreds of volts required to drive the motor.

In addition, in electric vehicles, auxiliary equipment such as electric equipment (controller, lamp, air conditioner) and the like are provided as equipment that requires electric power, in addition to a traveling motor. Regarding how to obtain the operating power of the auxiliary machinery, a method of using a battery (for example, one) of a battery power source for traveling as a battery power source for the auxiliary machinery can be considered. However, in that case, the power consumption of only the battery used as the battery power source for the auxiliary device increases, the deterioration is accelerated, and the balance with other batteries is deteriorated.

Therefore, an auxiliary battery power source is provided separately from the traveling battery power source, and the auxiliary battery power source supplies electric power to the auxiliary machinery. The auxiliary battery power source outputs a 12-volt voltage, and has a relatively small capacity.

With the adoption of this auxiliary battery power supply, a DC / DC converter is prepared as a charging voltage output means, and the running battery power supply voltage is transformed (stepped down) by the DC / DC converter while the electric vehicle is in operation. ), The same voltage charges the battery power source for the auxiliary equipment. This prevents the so-called battery depletion of the auxiliary battery power source.

Such an auxiliary battery power source and DC
Examples of electric vehicles equipped with a / DC converter are disclosed in Japanese Patent Laid-Open Nos. 64-85502 and 3-124201.

[0007]

The DC / DC converter is provided with an overcurrent protection circuit and an overvoltage protection circuit as a means for protecting against abnormalities. When this protection function works, DC
The operation of the / DC converter stops, and charging of the auxiliary battery power supply becomes impossible.

Further, the DC / DC converter becomes considerably high in temperature during operation, and there is a possibility that an abnormality such as disconnection may occur inside due to the influence of the temperature. Also in this case, charging of the auxiliary battery power supply becomes impossible.

If the vehicle continues to run without the auxiliary battery power being charged, the battery will eventually run out, and the auxiliary machines will not operate, and the vehicle will be unable to run. The present invention takes the above circumstances into consideration, and the power supply device for an electric vehicle according to the first to fifth inventions operates the auxiliary devices even when the battery power supply for the auxiliary devices cannot be charged. The purpose is to be able to extend the mileage continuously for as long as possible, and thereby to make it possible for the vehicle to sufficiently reach a safe place or a place where maintenance is possible.

The power supply system for an electric vehicle according to the sixth aspect of the present invention can extend the traveling distance by continuing the operation of the auxiliary machinery as long as possible even when the battery power supply for the auxiliary machinery cannot be charged. Therefore, an object of the present invention is to allow the vehicle to sufficiently reach a safe place or a maintainable place, and further inform the driver that charging is not possible, thereby improving safety.

[0011]

According to a first aspect of the present invention, there is provided a power supply device for an electric vehicle, which has a plurality of batteries, and which supplies a driving battery power source for outputting driving power to a driving motor and auxiliary devices. Abnormality of the charging voltage output means for stepping down the voltage of the battery power supply for auxiliary equipment that outputs electric power and the voltage of the battery power supply for traveling, and outputting the same voltage as the charging voltage for the battery power supply for auxiliary equipment. And a connection switching means for directly connecting the auxiliary battery power supply to a part of the traveling battery power supply when the abnormality detection means detects an abnormality.

A power supply device for an electric vehicle according to a second aspect of the present invention is the power supply device for an electric vehicle according to the first aspect of the present invention, in which the batteries of the traveling battery power source are connected in series. A power supply device for an electric vehicle according to a third aspect of the present invention is, as the charging voltage output means of the first aspect of the present invention, a DC / DC that temporarily converts a direct current voltage into an alternating current and transforms it, and rectifies and outputs the transformed voltage. A converter is used.

In the power supply device for an electric vehicle of the fourth invention, the abnormality detection means of the first invention detects at least one of the voltage and the current output from the charging voltage output means, and which one of the detection results is obtained. When either one is zero, it is determined to be abnormal.

According to a fifth aspect of the present invention, there is provided a power supply device for an electric vehicle, wherein when the connection switching means of the first aspect detects an abnormality in the abnormality detecting means, each battery of the traveling battery power source is set to 2
It is separated into one set and one set is connected to an auxiliary battery power source, and the other set is left for driving the traveling motor. Sixth
In addition to the configuration of the first invention, the power supply device for an electric vehicle according to the invention of claim 1 is provided with a notification means for notifying that when the abnormality detection means detects an abnormality.

[0015]

In the power supply system for the electric vehicle of the first invention,
The traveling motor is driven by the voltage of the traveling battery power source, and the auxiliary machinery is operated by the voltage of the auxiliary battery power source. Further, the voltage of the traveling battery power source is stepped down by the charging voltage output means, and the auxiliary battery power source is charged. When an abnormality occurs in the charging voltage output means, it is detected by the abnormality detection means. At this time, the auxiliary battery power supply is directly connected to a part of the traveling battery power supply.

In the power supply device for the electric vehicle of the second invention, the high voltage required for driving the motor is output from the battery power source for traveling. In the power supply device for the electric vehicle of the third invention, the charging voltage for the traveling battery power source is DC / D.
It is output from the C converter.

In the power supply device for an electric vehicle according to the fourth aspect of the present invention, the charging voltage output means is determined to be abnormal when at least one of the voltage and the current output from the charging voltage output means is zero.

In the electric power supply system for an electric vehicle according to the fifth aspect of the present invention, when an abnormality is detected by the abnormality detecting means, each battery of the traveling battery power source is separated into two sets, and one set has the auxiliary battery. The power supply is connected and the other set remains for driving the drive motor. In the power supply device for an electric vehicle according to the sixth aspect of the invention, when an abnormality is detected by the abnormality detecting means, the fact is notified.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a traveling battery power source, which connects a plurality of batteries 2a, 2b, ..., 2n in series and outputs a voltage required for driving a traveling motor 4 described later. Specifically, it prepares 20 12-volt batteries, connects them in series, and outputs a high voltage of several hundred volts.

Among the respective batteries constituting the traveling battery power source 1, between the first battery 2a and the second battery 2b, the second battery 2b and the third battery 2c are connected. Normally connected relay connection 2 between the third battery 2c and the fourth battery 2d.
1, 22, 23 are respectively inserted and connected.

A motor controller 3 is connected to the traveling battery power source 1, and a traveling motor 4 is connected to the output end of the motor controller 3. The motor controller 3 is
The voltage (DC voltage) of the traveling battery power supply 1 is converted into a voltage of a predetermined frequency (and level) by switching and is output. This output serves as drive power for the traveling motor 4.

The traveling motor 4 is an AC motor, operates at a speed according to the output of the motor controller 3, and drives the wheels of the electric vehicle. A DC / DC converter 5 is connected to the traveling battery power source 1 as a charging voltage output means. The DC / DC converter 5 temporarily converts the voltage (DC voltage) of the traveling battery power source 1 into AC, transforms (steps down) the voltage, rectifies the transformed voltage, and outputs the rectified voltage.

An auxiliary battery power source 6 is connected to the output terminal of the DC / DC converter 5, and auxiliary machinery 7 such as electrical equipment (controller, lamp, air conditioner) is connected to the auxiliary battery power source 6. The auxiliary battery power source 6 outputs a voltage of 12 V and has a relatively small capacity.

The batteries 2a, 2 of the traveling battery power source 1
b, 2c positive side terminals are normally open relay contacts 3
1, 32, 33 are connected to each other, and the interconnection point is connected via a normally open relay contact 34 to the auxiliary battery power source 6
Connected to the positive terminal of. In addition, the batteries 2a, 2b,
The negative terminals of 2c are normally open relay contacts 41, 4
2, 43, and the interconnection point is connected to the negative side terminal of the auxiliary machine battery power source 6 through a normally open relay contact 44.

Each battery of the traveling battery power source 1 is divided into a group consisting of the batteries 2a, 2b and 2c and a group consisting of the remaining batteries 2d, ... 2n. The input end of the motor controller 3 is connected to the set of batteries 2d, ... 2n via a normally open relay contact 51.

On the other hand, a current sensor 8 is attached to a connection line between the output end of the DC / DC converter 5 and the auxiliary battery power source 6. The current sensor 8 detects the output current of the DC / DC converter 5. This detection result is sent to the abnormality detection unit 10. A relay circuit 11 is connected to the abnormality detection unit 10 as connection switching means, and the alarm device 1 is also provided.
2 are connected.

The abnormality detecting section 10 constitutes an abnormality detecting means together with the current sensor 8. When the detection result of the current sensor 8 is zero, the DC / DC converter 5 has an abnormality (abnormality which is a target of overload protection, Alternatively, it is determined that a disconnection abnormality) has occurred. In addition, when the abnormality detection unit 10 determines an abnormality,
In addition to giving an operation command to the relay circuit 11, the alarm 1
Turn on 2.

The relay circuit 11 is a group of several relays having the above-mentioned relay contacts as constituent elements. The alarm 12 is, for example, a lamp, and is provided in a place where the driver can see, such as the cab of an electric vehicle.

Next, the operation of the above configuration will be described. The voltage of the traveling battery power source 1 is converted into a voltage of a predetermined frequency (and level) by the motor controller 3 and supplied to the traveling motor 4. As a result, the traveling motor 4 is driven and the electric vehicle runs.

The voltage of the traveling battery power source 1 is DC / DC.
It is also supplied to the converter 5, and the output voltage of the DC / DC converter 5 is charged in the auxiliary battery power supply 6. Then, the auxiliary machinery 7 is operated by the voltage of the auxiliary battery power source 6.

If any abnormality occurs in the DC / DC converter 5, the auxiliary battery power source 6 cannot be charged. If the vehicle continues to travel as it is, the battery power source 6 for the auxiliary machine will eventually run out of battery, the auxiliary machines 7 will not operate, and the vehicle will be unable to travel.

However, at the time of this abnormality, the output current of the DC / DC converter 5 becomes zero, which is detected by the current sensor 8. With this detection, the abnormality detection unit 10 determines an abnormality, and according to the determination, the relay circuit 11 and the alarm device 1
2 works.

When the relay circuit 11 is activated, the relay contacts 21, 22, 23 are opened and the relay contacts 31, 3 are also opened.
2, 33, 34, 41, 42, 43, 44, 51 are closed. The operation of the alarm 12 informs the driver that charging of the auxiliary battery power source 6 has become impossible.

When the relay contacts 21, 22, 23 are opened, the batteries 2a, 2b, 2c in the traveling battery power source 1 are opened.
Are disconnected one by one. Relay contact 31,3
When 2, 33, 34 are closed, the positive terminals of the separated batteries 2a, 2b, 2c are directly connected to the positive terminals of the auxiliary battery power source 6.

When the relay contacts 41, 42, 43, 44 are closed, the negative terminals of the batteries 2a, 2b, 2c are directly connected to the negative terminals of the auxiliary battery power source 6. That is, the batteries 2a, 2b, 2c are connected in parallel with each other, and the voltage of the parallel circuit is applied to the auxiliary machine battery power source 6.

As described above, by applying a partial battery voltage of the traveling battery power source 1 to the auxiliary battery power source 6, even if charging by the DC / DC converter 5 becomes impossible, It is possible to continuously operate the auxiliary machinery 7 for as long as possible while preventing the battery power of the battery power source 6 from being exhausted as much as possible.

When the relay contact 51 is closed, the remaining batteries 2d, ...
The motor controller 3 is connected to n. This allows
The operation of the traveling motor 4 is continued.

In this way, by continuing the operation of the auxiliary machinery 7 and the operation of the traveling motor 4, it is possible to sufficiently reach the safe place or the maintainable place of the vehicle.

Moreover, since the driver 12 is notified by the operation of the alarm device 12, the driver can take prompt and appropriate measures such as immediately going to the safe place or the place where maintenance is possible. The safety can be improved.

In the above embodiment, the output current of the DC / DC converter 5 is detected by the current sensor 8. However, a voltage sensor is provided instead of the current sensor, and an abnormality is detected based on the output voltage of the DC / DC converter 5. It may be configured to detect.
The point is that at least one of the voltage and the current output from the DC / DC converter 5 is detected, and when the detection result is zero, it may be determined as abnormal.

In the above embodiment, the case where the motor controller 3 is separate from the auxiliary machinery 7 has been described as an example, but the same applies to the case where the motor controller 3 is included in the auxiliary machinery 7. it can. Besides, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.

[0042]

As described above, the electric power supply system for an electric vehicle according to the first to fifth aspects of the invention drives the traveling motor with the voltage of the traveling battery power source, and also uses the voltage of the auxiliary battery power source. The auxiliary equipment is operated, and the voltage of the traveling battery power supply is reduced by the charging voltage output means to charge the auxiliary equipment battery power supply.When an abnormality occurs in the charging voltage output means, it is detected by the abnormality detection means. Since it is configured to detect and directly connect the battery power for auxiliary equipment to a part of the battery power for traveling, even if charging of the battery power for auxiliary equipment becomes impossible, the operation of auxiliary equipment will be as long as possible. The mileage can be extended continuously for a period of time, which allows the vehicle to sufficiently reach a safe place or a place where maintenance is possible. Sixth
Since the power supply device for an electric vehicle according to the invention of the invention is configured to notify the abnormality by the notification means, the safety can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an electric circuit according to an embodiment.

[Explanation of symbols]

1 ... Running battery power source, 2a, 2b, ... 2c ... Battery, 3 ... Motor controller, 4 ... Running motor, 5
... DC / DC converter (charging voltage output means), 6 ... Battery power source for auxiliary machinery, 7 ... Auxiliary machinery, 8 ... Current sensor, 10
... Abnormality detection section, 11 ... Relay circuit (connection switching means), 1
2 ... Alarm device 21, 22, 23 ... Normally closed relay contact,
31, 32, 33, 34, 41, 42, 43, 44, 5
1 ... Normally open relay contact.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Naotake Kumagai 5-3-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (72) Hisamitsu Koga 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Automotive Industry Co., Ltd.

Claims (6)

[Claims] 1. A traveling battery power source that has a plurality of batteries and outputs drive power to a traveling motor, an auxiliary battery power source that outputs electric power to auxiliary machinery, and the traveling battery power source. The charging voltage output means for transforming the voltage and outputting the same voltage as the charging voltage for the battery power supply for the auxiliary machine, the abnormality detecting means for detecting an abnormality of the charging voltage output means, and the abnormality detecting means have detected an abnormality. A power supply device for an electric vehicle, comprising: a connection switching unit that connects the auxiliary battery power supply to a battery of a part of the traveling battery power supply in parallel. 2. The electric power supply apparatus for an electric vehicle according to claim 1, wherein the traveling battery power source has a plurality of batteries connected in series. 3. The power supply device for an electric vehicle according to claim 1, wherein the charging voltage output means is a DC / DC converter that converts (steps down) a DC voltage and outputs the DC voltage. Power supply equipment. 4. The electric vehicle power supply device according to claim 1, wherein the abnormality detection means detects at least one of the voltage and the current output from the charging voltage output means, and when the detection result is zero. A power supply device for an electric vehicle, characterized in that it is determined to be abnormal. 5. The power supply device for an electric vehicle according to claim 1, wherein the connection switching means detects an abnormality by the abnormality detecting means,
An electric vehicle characterized in that each battery of a traveling battery power source is separated into two groups, one of the groups is connected with an auxiliary battery power source in parallel, and the other group is left for driving a traveling motor. Power supply equipment. 6. The power supply apparatus for an electric vehicle according to claim 1, further comprising a notifying means for notifying the abnormality detection means when an abnormality is detected by the abnormality detection means. .