JP2002209307A - High voltage battery cooling system - Google Patents

Abstract

(57) [Problem] To drive a cooling fan of a high-voltage battery without using a low-voltage battery on the vehicle side even when charging a high-voltage battery of an electric vehicle or a hybrid vehicle from an external charging device. Even when the common potential of the high voltage circuit (minus side of 300 V) and the common potential of the low voltage circuit (minus side of 24 V) are separated from each other, the high voltage power supply and the low voltage power supply are connected to each other using the charging device connected to the common potential. Allow the battery to charge. A cooling fan of a high voltage battery is driven by a low voltage power output of a charging device. When the output plug of the charging device is connected to the receptacle of the vehicle or when the open / close circuit of the low-voltage battery of the vehicle is turned off, the relay is activated to connect the common potential of the high-voltage circuit and the common potential of the low-voltage circuit. I do.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to an electric vehicle or a hybrid vehicle that runs using both an internal combustion engine and a motor generator. INDUSTRIAL APPLICABILITY The present invention is applied to an automobile equipped with both a high-voltage battery for charging and holding electric energy for traveling and a low-voltage battery for supplying operating current to various devices mounted on the vehicle. The present invention relates to a cooling device for a high-voltage battery that stores electric energy generated when a motor generator operates as a generator and supplies electric energy when the motor generator operates as a motor.

[0002]

2. Description of the Related Art An electric vehicle or a hybrid vehicle is equipped with a high-voltage battery as a DC power supply to be supplied to an electric motor (or motor generator) for traveling. The rated terminal voltage of the high-voltage battery is, for example, 300V. On the other hand, an electric vehicle or a hybrid vehicle is equipped with a low-voltage battery, in addition to the high-voltage battery, for supplying various lamps, various control circuits such as a computer, acoustic equipment, a cooling / heating device, and the like. The terminal voltage of the low-voltage battery is, for example, 24 V (standard for large vehicles) or 12 V (standard for small vehicles).

A high-voltage battery has been mounted in a housing attached to a vehicle because of the danger of electric shock when a human body touches the circuit during maintenance work or the like. Further, since this high-voltage battery generates heat during charge and discharge, a cooling device for blowing air from an electric cooling fan has been provided in its housing. The power supply current for the cooling fan and its control circuit is supplied from a low-voltage battery mounted on the vehicle in principle. Or JP-A-4-31
No. 2304 describes a circuit for driving a cooling fan of a high-voltage battery by dividing a voltage from a high-voltage power supply for charging the high-voltage battery by a resistance circuit.

Further, a high-voltage circuit supplied from a high-voltage battery is connected to an inverter and a motor generator. The common potential (often on the negative side) of this high-voltage circuit is common to the low-voltage circuit supplied from the low-voltage battery. A technique for separating the potential from the potential (mostly on the negative side) has been used (see Japanese Patent Application Laid-Open No. H7-177674). This is because there is a danger that a tool or a human body may touch the high-voltage circuit by mistake when inspecting the vehicle, etc. It is something to keep. By setting the high-voltage circuit to a floating potential in this way, even when a tool or a human body touches the high-voltage circuit, the return path to the ground is cut off so that a large current does not flow directly.

[0005] In such electric vehicles or hybrid vehicles, it is often necessary to charge a high-voltage battery holding electric energy for traveling with an external power supply.
That is, whether the vehicle is equipped with a charging generator and driven by the internal combustion engine, or when the vehicle is braked to generate power using electric braking, the charging energy of the high-voltage battery is consumed and insufficient during traveling. become. When the charge amount of the high-voltage battery is reduced, a cable is connected from a charging device mounted on the depot or the like to an electric terminal of the vehicle, and equipment is provided so that the high-voltage battery can be charged through the cable. I have.

[0006] A charging device for charging such a high-voltage battery that has been sold so far is provided with a charging power source for the high-voltage battery (for example, rated voltage of 300 V) and a charging power source for the low-voltage battery (for example, rated voltage of 24 V). The low voltage battery can be charged at the same time if necessary. In such a device, a plug is provided at the end of a charging cable, and this plug is connected to a receptacle provided as an electric terminal on the vehicle side.
The plug has a standard three-terminal structure, and a common potential (for example, a minus side) of a high-voltage power supply and a common potential (for example, a minus side) of a low-voltage power supply are commonly connected.

[0007]

As described above, the high-voltage battery also generates heat when the high-voltage battery of the stopped vehicle is charged from the external charging device. When the high-voltage battery is mounted on the housing, the high-voltage battery has a high temperature, so it is necessary to drive a cooling fan to blow air into the housing. However, when charging the high-voltage battery, the vehicle is stopped and its electric circuit, particularly the low-voltage circuit, is often in a state where the battery power is off, and the cooling fan cannot be driven using the low-voltage battery of the vehicle as a power supply. If the cooling fan is driven by using the low-voltage battery of the vehicle while the high-voltage battery is being charged, the charging energy of the low-voltage battery will be consumed. For example, charging high-voltage batteries from the end of the evening
Generally, the procedure is performed until the start of operation the next morning, and it is not desirable to use the current of the low-voltage battery during this time to drive the cooling fan.

Further, in a vehicle having a structure in which the common potential (minus side) of the high voltage circuit and the common potential (minus side) of the low voltage circuit are separated as described above, an external charging device is connected to the high voltage circuit of the vehicle via a cable. When connected to the terminal of the battery, the low potential circuit of the vehicle is not connected to the common potential (negative side), and the vehicle cannot use the low voltage power source of the charging device. In a vehicle having a structure in which the common potential of the two power supplies is separated as described above, when simultaneously using the high-voltage power supply and the low-voltage power supply supplied from the external charging device, an operation switch that connects the two common potentials by operation is provided. It is conceivable to provide this switch on the vehicle, but if you forget to operate such an operation switch at the start of charging, charging will be performed without the cooling fan operating, and if you forget to operate at the end of charging, the two power supplies will be shared. It loses meaning such as avoiding certain dangers by separating potentials.

The present invention has been made in such a background, and even when a high-voltage battery is charged from an external charging device, a cooling fan that blows air into a housing in which the battery is disposed is continuously used for a long time. It is an object to provide a device that can be driven. The present invention is also applicable to a vehicle in which the common potential of the high-voltage circuit and the common potential of the low-voltage circuit are separated from each other automatically when the external charging device is connected, without performing any special switch operation or the like. It is an object of the present invention to provide a device to which a common potential of each of a high-voltage circuit and a low-voltage circuit is connected so that a high-voltage power supply and a low-voltage power supply supplied from a charging device can be simultaneously used on a vehicle side. The present invention automatically disconnects the common potential of the high-voltage circuit of the vehicle from the common potential of the low-voltage circuit without performing a special switch operation even when the charging of the high-voltage battery is completed and the connection with the charging device is disconnected. It is intended to provide a device to be used.

[0010]

SUMMARY OF THE INVENTION According to the present invention, when a charging device having both a high voltage power source and a low voltage power source is connected to a vehicle power source, a low voltage supplied from the charging device is charged while the high voltage battery of the vehicle is being charged. A circuit for driving a cooling fan of a high-voltage battery by using a current of a power supply is provided. Further, in a vehicle in which the common potential of the high-voltage circuit and the low-voltage circuit is separated, when the external charging device is connected, the two common potentials are connected in conjunction with each other, and the current of the low-voltage power supply supplied from the external charging device is simultaneously transmitted. It is characterized in that it can be used.

That is, the present invention comprises a high-voltage battery (1) mounted in a housing (3) mounted on a vehicle, and a low-voltage battery (2) mounted on the vehicle. A cooling device (5) having both a high-voltage power supply and a low-voltage power supply is used in a cooling device for a high-voltage battery including a cooling fan (4) connected to the circuit of (3) and blowing air into the housing (3). A circuit (6) for supplying the cooling fan (4) from the low voltage power supply of the charging device (5) in conjunction with the connection of the high voltage battery (1) to the high voltage power source of the charging device (5); It is characterized by.

The charging device (5) and the batteries (1, 2) mounted on the vehicle are connected via one plug (7) having both a high-voltage circuit and a low-voltage circuit and a receptacle (8). With this configuration, the connection of the high-voltage circuit and the connection of the low-voltage circuit can be linked.

The numerals in the parentheses are reference numerals for the drawings of the embodiments described later. The reference numerals are provided to facilitate understanding of the configuration of the present invention, and are not intended to limit the configuration of the present invention to the embodiments.
The same applies to the following description.

With this configuration, it is possible to continuously drive the cooling fan for cooling the high-voltage battery over a period in which the high-voltage battery is charged. Even if the cooling fan is driven for a long time, the low-voltage battery of the vehicle is not consumed. With this configuration, the low-voltage power supply output of the charging device is connected to the cooling fan in conjunction with one operation of connecting the high-voltage power supply to the vehicle.

The circuit for connecting the cooling fan to the low-voltage power supply of the charging device includes a backflow prevention diode for preventing the output current of the low-voltage battery from flowing into the charging device. be able to.

The electric wiring on the vehicle side is common to a common potential of a high voltage circuit to which a device using the high voltage battery (1) is connected and a common potential to a low voltage circuit to which a device using the low voltage battery (2) is connected. When the low-voltage battery (2) is separated from the low-voltage circuit by the switching circuit (10) or the like when the configuration is separated from the potential, the common potential of the high-voltage circuit is changed to the common potential of the low-voltage circuit. To be provided with a relay circuit (11) connected to the relay circuit.

Similarly, the electric wiring on the vehicle side is common to a common potential of a high-voltage circuit to which a device using the high-voltage battery (1) is connected and a common potential to a low-voltage circuit to which a device using the low-voltage battery (2) is connected. When the configuration is separated from potential,
During the period in which the plug (7) and the receptacle (8) are connected, a configuration may be provided that includes a relay circuit (12) that connects the common potential of the high-voltage circuit to the common potential of the low-voltage circuit.

With this configuration, the operation of connecting the plug of the charging device for charging the high-voltage battery to the receptacle on the vehicle side automatically connects the two common potentials on the vehicle side, and the low voltage supplied from the charging device. The power supply can be used on the vehicle side. Also, the connection of the two common potentials on the vehicle side is automatically separated by the operation of disconnecting the plug of the charging device from the receptacle, so any special operation is required to connect and disconnect the common potential on the vehicle side. There is no problem that causes problems such as forgetting operation after charging is completed.

[0019]

(First Embodiment) FIG. 1 is an electric circuit diagram of a main part of an apparatus according to a first embodiment of the present invention. The circuit on the right side of the figure is a vehicle-side circuit. This vehicle is equipped with a high-voltage battery 1 having a rated voltage of 300 V for holding electric energy for traveling and a low-voltage battery 2 having a rated voltage of 24 V supplied to various devices of the vehicle. ing. From the high-voltage battery 1 via an inverter (not shown),
Electric energy is transferred between a driving axle of the vehicle and a motor generator connected thereto. That is, when the vehicle is accelerated, electric energy is supplied from the high-voltage battery 1 to the motor generator, and when the vehicle is braked, the electric energy generated from the motor generator is regeneratively charged. Since the high-voltage battery 1 has a large capacity and a high terminal voltage, the high-voltage battery 1 is housed in a metal casing 3 so that it cannot be easily operated from the outside. Since the high-voltage battery 1 generates heat during charging and discharging, the housing 3 is configured to be blown and cooled by a cooling fan 4. The cooling fan 4 is connected to the low-voltage battery 2 (24) via the switching circuit 10 and the diode 13 while the vehicle is running.
V).

The high-voltage battery 1 is repeatedly discharged and charged by running the vehicle, but may be discharged gradually depending on the operating condition. In this case, it is necessary to perform supplementary charging when the vehicle is not used from outside. is necessary. For example, in an operation mode in which this vehicle is used for a city bus, the charging state is maintained by slowly charging the vehicle depot for a long time at a time when the vehicle is not operating at night. Is done. Prolonged gentle charging prolongs the life of the high-voltage battery. Even during such long-time charging, the temperature of the high-voltage battery 1 rises, so that the cooling fan 4 must be driven and rotated continuously to perform cooling.

In this device, a charging device 5 is provided at a vehicle depot. This charging device 5 includes an AC commercial power supply 100
Alternatively, a charging current for charging a battery with a DC rated voltage of 300 V can be generated using 200 V as a power supply. At the same time, a charging current for charging a battery having a rated DC voltage of 24 V can be generated from the AC commercial power supply 100 or 200 V. This output is connected to one cable 14
To the three terminals of the plug 7. This 3
The first of the terminals is + 300V, the second is + 24V, and the third is 0V which is a common potential. This plug 7 is connected to a receptacle 8 provided on the vehicle.

On the other hand, in this vehicle, as described above, the common potential of the high voltage circuit supplied from the high voltage battery 1 (minus side of 300 V) and the common potential of the low voltage circuit supplied from the low voltage battery 2 (minus 24 V). , And is configured to be used as a disconnected state. For details of this configuration and operation, refer to the above-mentioned prior art publication. Therefore, when the terminal of the common potential (0 V) among the three terminals of the receptacle 8 is connected to the negative side of the high voltage battery 1, the low voltage power supply 24V has no current return path and cannot be used. Therefore, in the present invention, when the switching circuit 10 of the low-voltage power supply (24 V) on the vehicle side is turned off, the energized state of the relay 11 connected to the switching circuit 10 is released, and the negative side of the high-voltage battery 1 It is configured to be connected to the negative common potential of the power supply. Switching circuit 10
Is turned off, for example, when the operation of the vehicle ends and the vehicle is stored in the garage. At this time, there is no problem even if the common potential of the high-voltage circuit and the low-voltage circuit is connected because no vehicle inspection or the like is performed.

When the relay 11 connects the negative side of the high-voltage battery 1 to the negative side of the low-voltage battery 2, the circuit for driving the cooling fan 4 from the receptacle 8 via the circuit 6 is closed. That is, the switching circuit 10 of the low-voltage power supply is turned off, and the operation of connecting the plug 7 of the charging device 5 to the receptacle 8 on the vehicle side allows the charging of the high-voltage battery 1 without any other switch operation. The cooling fan 4 is driven throughout the period to cool the high-voltage battery 1. When the plug 7 is removed from the receptacle 8, the cooling fan 4 automatically stops rotating. When the switching circuit 10 is turned on to start the operation, the relay 11 is energized and the two common potentials are automatically separated.

(Second Embodiment) FIG. 2 is a circuit diagram of a device according to a second embodiment of the present invention. In the device of the first embodiment, a normally-on contact, that is, a contact that is closed when not energized, is used as a relay circuit. In the device of the second embodiment, the relay 12 is normally off, that is, energized. If not, the open contacts are used.

That is, in the circuit shown in FIG.
Is connected to the receptacle 8, the relay 12 is energized by the low-voltage power supply 24V, and connects the negative side of the high-voltage battery 1 to the negative side of the low-voltage battery 2. The cooling fan 4 is supplied with low-voltage power from the charging device 5 via the diode 9, and can drive and rotate the cooling fan 4 throughout the charging period. When the switching circuit 10 is closed before the plug 7 is removed from the receptacle 8, the diode 9 is energized by the low-voltage battery 2, and the diode 12 is activated even after the plug 7 is removed. This is a backflow prevention diode provided so as not to remain in the energized state.

Also in this second embodiment, the two common potentials are connected by simply connecting the plug 7 of the charging device to the receptacle 8 of the vehicle, and the cooling fan 4 is driven and rotated by the external power supply during charging. Can be. In the second embodiment, the low-voltage battery 2 can be charged at the same time by closing the switching circuit 10 while the high-voltage battery 1 is being charged.

In the above-mentioned two embodiments, the wound type relay is used as the relay. However, the present invention can be similarly implemented by using a thyristor or other semiconductor relay. Although the above two embodiments have been described here,
The circuit of the present invention can be realized in various ways.

[0028]

According to the apparatus of the present invention, even when a high-voltage battery is charged for a long time using an external charging device, the cooling fan that blows air into the housing in which the battery is disposed is continuously operated over the charging time. Can be driven. Further, even in a vehicle in which the common potential of the high-voltage circuit and the common potential of the low-voltage circuit are separated, when an external charging device is connected, the high-voltage circuit of the vehicle is automatically operated without performing a special switch operation or the like. And the common potential of the low-voltage circuit are connected to each other, so that the high-voltage power supply and the low-voltage power supply supplied from the charging device can be simultaneously used on the vehicle side. Further, even when the charging of the high-voltage battery is completed and the connection with the charging device is disconnected, the common potential of the high-voltage circuit and the common potential of the low-voltage circuit of the vehicle are automatically disconnected without performing a special switch operation. The state can be restored.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of an apparatus according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram of a device according to a second embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 high-voltage battery 2 low-voltage battery 3 housing 4 cooling fan 5 charging device 6 low-voltage power supply circuit for driving cooling fan 7 plug 8 receptacle 9 backflow prevention diode 10 switching circuit 11 relay (normally on) 12 relay (normally off) ) 13 diode 14 cable

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kunitoshi Shimizu 3-1-1, Hinodai, Hino-shi, Tokyo Hino Motors Co., Ltd. (72) Takuto Matsubara 3-1-1, Hinodai, Hino-shi, Tokyo Hino (72) Inventor Tetsuya Itasaka 3-1-1, Hinodai, Hino-shi, Tokyo F-term (reference) 3D038 AA09 AB01 AC11 5H030 AA06 AS08 BB02 BB09 BB14 BB22 DD09 DD12 DD18 DD27 DD30 5H031 AA09 CC05 CC09 KK00 5H115 PA08 PC06 PG04 PI16 PI29 PI30 PO01 PO07 PO10 PO14 PU21

Claims (5)

[Claims] 1. A high-voltage battery mounted in a housing mounted on a vehicle, and a low-voltage battery mounted on the vehicle, and a cooling fan connected to a circuit of the low-voltage battery and blowing air into the housing. In the cooling device for a high-voltage battery provided, a charging device having both a high-voltage power supply and a low-voltage power source is used, and when the high-voltage battery is connected to the high-voltage power supply of the charging device, the cooling fan operates in conjunction with the low voltage of the charging device. A cooling device for a high-voltage battery, comprising a circuit to be supplied from a power supply. 2. The cooling device for a high-voltage battery according to claim 1, wherein the charging device and the battery mounted on the vehicle are connected via a single plug and a receptacle having both a high-voltage circuit and a low-voltage circuit. 3. The high-voltage battery according to claim 1, wherein the circuit for connecting the cooling fan to a low-voltage power supply of the charging device includes a backflow prevention diode for preventing an output current of the low-voltage battery from flowing into the charging device. Cooling system. 4. The high-voltage battery cooling device according to claim 1, wherein a common potential of a high-voltage circuit connected to the device using the high-voltage battery and a common potential of a low-voltage circuit connected to the device using the low-voltage battery. And a cooling device for a high-voltage battery including a relay circuit that connects a common potential of the high-voltage circuit to a common potential of the low-voltage circuit during a period when the low-voltage battery is disconnected from the low-voltage circuit. . 5. The high-voltage battery cooling device according to claim 2, wherein a common potential of a high-voltage circuit connected to a device using the high-voltage battery and a common potential of a low-voltage circuit connected to a device using the low-voltage battery. And a high voltage battery cooling device including a relay circuit for connecting a common potential of the high voltage circuit to a common potential of the low voltage circuit during a period when the plug and the receptacle are connected.