JP2012205382A - Power supply device for vehicle - Google Patents

Abstract

An object of the present invention is to reduce the size of a power supply device for a vehicle while sufficiently ensuring the safety of an operator at the time of inspection work or the like.
In a battery pack for supplying power to a motor generator for traveling, a high voltage battery is a first set on one end side output terminal 22a formed by connecting a plurality of single cells in series. The battery 32 and the second assembled battery 33 on the other end side output terminal 22b side are configured. The battery box 20 houses a relay unit 24 that opens and closes an electrical connection between the first assembled battery 32 and the one end side output terminal 22a. In addition, the first assembled battery 32 and the second assembled battery 32 are positioned between the first assembled battery 32 and the second assembled battery 33 so as to be positioned on the other end side of the intermediate voltage position of the high voltage battery 12. A plug unit 31 that opens and closes an electrical connection with the assembled battery 33 is provided. The maximum voltage v2 of the second assembled battery 33 is set to a safe voltage.
[Selection] Figure 1

Description

  The present invention relates to a vehicle power supply device for supplying power to a traveling electric motor mounted on a hybrid vehicle or an electric vehicle.

  A hybrid vehicle including an engine and an electric motor as a driving source, and an electric vehicle including only an electric motor as a driving source are equipped with a high voltage battery (traveling battery) that supplies electric power to the traveling electric motor. A high voltage battery is configured by connecting a plurality of battery cells made of single cells in series with each other in order to obtain a voltage and a discharge capacity necessary for driving an electric motor for traveling. The high-voltage circuit that electrically connects the high-voltage battery and the electric motor for traveling is insulated from the vehicle body to ensure the safety of the passenger. For example, a high voltage battery is housed in a battery box, and the high voltage circuit in the battery box is mounted on the vehicle as a battery pack (vehicle power supply device) in a state insulated from the vehicle body.

  A relay unit is provided in the battery box so as to be positioned on one end side of the high voltage battery. The opening / closing operation of the relay unit is controlled based on a signal from the vehicle control device. When the relay unit is closed, the high voltage battery and the electric motor are electrically connected, and the vehicle is in an operating state. On the other hand, when the relay unit is opened, the electrical connection between the high voltage battery and the electric motor is cut off, and the vehicle becomes inoperative.

  Such a battery pack has a safety plug device for cutting off a high-voltage circuit in the battery pack, for example, as described in Patent Document 1, for the purpose of ensuring safety during inspection work or maintenance work. Is provided. This safety plug device has a socket provided at the center of the high-voltage battery, and is arranged so that substantially the same voltage is generated on both sides of the socket. In a state where the plug is attached to the socket, the plurality of battery cells respectively provided on both sides of the socket are energized. On the other hand, in a state where the plug is detached from the socket, energization of the plurality of battery cells provided on both sides of the socket is interrupted.

  In the battery box, a circuit interruption relay is provided at the other end of the high voltage battery. The circuit interruption relay is a normally open type, and the circuit interruption relay is closed in conjunction with a vehicle start signal or the like. Accordingly, during inspection work and maintenance work, the vehicle is naturally in an operation stopped state, so that the safety plug is removed and the relays provided on both sides of the high voltage battery are opened. As a result, the high voltage circuit in the battery box is reliably cut off, so that the safety of the operator is ensured.

JP 2004-7920 A

  However, if the relays are provided on both sides of the high voltage battery as described in Patent Document 1, the battery pack becomes large and increases the cost. Therefore, it is conceivable to abolish either one of the relays. However, if the relay is abolished, the leakage of the battery pack may cause a leakage between the high-voltage circuit and the vehicle body on the side where the relay is abolished rather than the safety plug device. When a large potential difference occurs between them, there is no means for blocking this. In that case, there is a possibility that the safety of the worker cannot be sufficiently ensured at the time of inspection work or maintenance work.

  An object of the present invention is to reduce the size of a vehicle power supply device while sufficiently ensuring the safety of an operator during an inspection operation or the like.

  A vehicle power supply device according to the present invention is a vehicle power supply device that includes a traveling battery formed by connecting a plurality of single cells in series and supplies power to a traveling electric motor, and accommodates the traveling battery. One end side output terminal and the other end side output terminal, which are provided in the case body and are electrically connected to one end and the other end of the battery for traveling, respectively, are formed by connecting the plurality of unit cells in series, The first assembled battery on the one end side output terminal side and the second assembled battery on the other end side output terminal side constituting the battery for traveling, and the one end side output terminal and the first A first opening / closing means for opening and closing an electrical connection with the assembled battery; and the first assembled battery and the second assembled battery positioned at the other end side of the intermediate potential position of the traveling battery. And the first assembled battery And a second opening and closing means for opening and closing an electrical connection between the second battery pack and, and sets the maximum voltage of the second battery pack in a safe voltage.

  The vehicle power supply device of the present invention is characterized in that the safety voltage is 60 V or less in direct current.

  According to the present invention, the first opening / closing means is provided by positioning the second opening / closing means on the side where the first opening / closing means is not provided with respect to the position of the intermediate potential of the traveling battery. The maximum voltage of the second assembled battery arranged on the non-side is set to a safe voltage. As a result, even if a leakage occurs in the vehicle power supply device, a potential difference exceeding the upper limit value of the safety voltage is generated between the high voltage circuit and the vehicle body on the side where the first switching means is not provided. Can be prevented. Therefore, even if a circuit interruption relay is not provided between the second assembled battery and the other end side output terminal, it is possible to sufficiently ensure the safety of the operator, and by omitting the circuit interruption relay, the vehicle power supply device Can be reduced in size and cost.

It is the schematic which shows the high voltage circuit provided with the power supply device for vehicles which is one embodiment of this invention. It is the schematic which shows the state which leaked in the power supply device for vehicles in the high voltage circuit as a comparative example. It is the schematic which shows the state which leaked in the power supply device for vehicles in the high voltage circuit shown in FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing a high voltage circuit mounted on an electric vehicle. This electric vehicle is equipped with a traveling motor generator (electric motor) 10 as a drive source. The motor generator 10 is constituted by a three-phase AC motor, and a wheel drive shaft (not shown) is connected to the output shaft via a gear train. A high voltage battery (traveling battery) 12 for supplying electric power to the motor generator 10 is electrically connected to the motor generator 10 via an inverter 11. When braking the electric vehicle, the motor generator 10 is driven to generate electricity, so that kinetic energy can be converted into electric energy and recovered in the high voltage battery 12.

  The inverter 11 includes a plurality of switching elements (not shown) for converting a direct current from the high voltage battery 12 into a three-phase alternating current, a capacitor for stably supplying the direct current to each switching element, and the like. Yes. Each switching element is turned on / off by a control signal input to the inverter 11 from a vehicle control device (not shown). By controlling the current value and frequency of the three-phase alternating current supplied to the motor generator 10 via the inverter 11, the output torque and the rotation speed of the motor generator 10 are controlled.

  The inverter 11 is connected to a low voltage battery 14 via a DC / DC converter 13 (hereinafter referred to as a converter). For example, a lead storage battery having a rated voltage of 12V is used for the low voltage battery 14. The low voltage battery 14 supplies power to the inverter 11, the converter 13, and the vehicle control device, and also supplies power to vehicle auxiliary machines (not shown) such as a headlight, tail lamp, blinker, and blower. Further, by generating a low voltage current from the high voltage current via the converter 13, power is supplied from the high voltage battery 12 to the low voltage battery 14.

  The high-voltage circuit that electrically connects the motor generator 10 and the high-voltage battery 12 is insulated from the vehicle body, ensuring the safety of the passenger. As shown by a broken line in FIG. 1, the inverter 11 and the converter 13 are accommodated in the same container 16, and the vehicle provided as the motor control unit 17 in a state where a circuit provided in the container 16 is insulated from the vehicle body. It is mounted on. The inverter 11 and the converter 13 are electrically connected to each other by an energization line 18 routed in the container 16. The container 16 of the motor control unit 17 is provided with a plurality of output terminals 19 that are electrically connected to the inverter 11 and the converter 13 in the container 16. This prevents the outside of the container 16 from coming into contact with a circuit other than the output terminal 19 so that it is not necessary to touch the inside of the container 16 at normal times. Via these output terminals 19, the motor generator 10 and a battery pack 21 to be described later are electrically connected to the inverter 11, and the low voltage battery 14 is electrically connected to the converter 13.

  Although illustration is omitted, the motor control unit 17 is provided with a control terminal for controlling the inverter 11 and the converter 13. The motor control unit 17 is connected to the vehicle control device via this control terminal. In the present embodiment, the high voltage battery 12 and the converter 13 are separately connected to the inverter 11, but the present invention is not limited to this. For example, the inverter 11 and the converter 13 may be connected to the high voltage battery 12 in parallel.

  Similarly, the high voltage battery 12 is accommodated in a battery box (case body) 20, and a battery pack (vehicle power supply device) 21 is provided in a state where a high voltage circuit provided in the battery box 20 is insulated from the vehicle body. Installed in the vehicle. The battery box 20 is provided with one end side output terminal 22a and the other end side output terminal 22b that are electrically connected to one end and the other end of the high voltage battery 12 in the battery box 20, respectively. This prevents the outside of the battery box 20 from coming into contact with a high voltage circuit other than the output terminals 22a and 22b, so that it is not necessary to touch the inside of the battery box 20 at normal times. A high voltage circuit in the battery box 20 is electrically connected to the inverter 11 through the pair of output terminals 22a and 22b.

  Inside the battery box 20, a relay unit 24 serving as a first opening / closing means is accommodated between the high voltage battery 12 and the one end side output terminal 22a. The relay unit 24 is connected in parallel to the main relay 26 and a main relay 26 for opening and closing a power supply line 25 a that electrically connects one end (positive electrode) of the high-voltage battery 12 and one end-side output terminal 22 a. A resistor 27 and a sub-relay 28 are included. The opening and closing operations of the relays 26 and 28 are controlled by the vehicle control device. When the relay unit 24 is closed, the high voltage battery 12 and the inverter 11 are electrically connected, and the vehicle is in an operating state. On the other hand, when the relay unit 24 is opened, the electrical connection between the high voltage battery 12 and the inverter 11 is cut off, and the vehicle is in a non-operating state.

  In the relay unit 24, when the main relay 26 is closed while the capacitor provided in the inverter 11 is not sufficiently charged, an excessive current flows in the high voltage circuit due to the rapid charging of the capacitor. Become. Therefore, when the relay unit 24 is closed, an excessive current flows in the high voltage circuit by closing the sub relay 28 connected in series with the resistor 27 and then closing the main relay 26. Is prevented. The timing of the opening / closing operation of the relays 26 and 28 is controlled by the vehicle control device.

  Further, an ammeter 29 is provided in the battery box 20 so as to be positioned between the high voltage battery 12 and the other end side output terminal 22b. In order to measure the current value of the direct current flowing through the high voltage circuit in the battery box 20, the ammeter 29 is a power supply line 25b that electrically connects the other end (negative electrode) of the high voltage battery and the other end side output terminal 22b. Are connected in series. Based on a signal output from the ammeter 29 to the vehicle control device, the relay control unit 24 and the inverter 11 are controlled by the vehicle control device. Although not shown, the battery pack 21 is provided with a control terminal for controlling the relay unit 24, an output terminal for outputting a signal from the ammeter 29, and the like. The battery pack 21 is connected to the vehicle control device via these terminals.

  The high voltage battery 12 is configured by connecting a plurality of battery cells made of single cells in series with each other in order to obtain a voltage and a discharge capacity necessary for driving the motor generator 10. For example, in a recent electric vehicle, a rated voltage of the high-voltage battery 12 is obtained by connecting a plurality of battery cells, such as a nickel-hydrogen battery of about 1.2 V or a lithium-ion battery of about 3.6 V, as a single battery. Is about 330V. Here, 92 lithium ion batteries with a rated voltage per unit cell of about 3.6V are connected in series. That is, the maximum voltage v0 of the high-voltage battery 12 is set to be larger than twice the upper limit value (for example, 60V) of the safe voltage described later.

  The high voltage battery 12 is provided with a plug unit (safety plug device) 31 as second opening / closing means for the purpose of ensuring safety during inspection work and maintenance work. The plug unit 31 is positioned on the other end side (negative electrode side) from the intermediate potential position of the high voltage battery 12, that is, shifted to the side where the relay unit 24 is not provided from the central position of the high voltage battery 12. Has been placed. With the plug unit 31, the plurality of battery cells constituting the high-voltage battery 12 are disposed on the other end side with respect to the first assembled battery 32 disposed on one end side with respect to the plug unit 31. It is divided into the second assembled battery 33.

  The second assembled battery 33 provided on the other end side output terminal 22b side is set so that the maximum voltage v2 becomes a safe voltage by connecting a plurality of battery cells in series. Here, the safe voltage is a voltage that does not become a dangerous voltage (Hazardous Voltage) defined by an industrial standard such as UL standard or IEC standard. For example, in the UL standard, a voltage exceeding 60V in direct current is defined as a dangerous voltage. In this case, the safety voltage is a voltage of 60V or less in direct current. The first assembled battery 32 provided on the one end side output terminal 22a side is formed by connecting a plurality of battery cells other than the battery cells constituting the second assembled battery 33 in series with each other. For example, in the high voltage battery 12 that generates a rated voltage of about 330 V, the maximum voltage per unit cell is 4.2 V in order to set the maximum voltage v2 of the second assembled battery 33 to 60 V or less, which is a safe voltage. If the rated voltage is set to be 50.4V by connecting 14 battery cells in series so that the maximum voltage is 58.8V, the first assembled battery 32 has 78 pieces. The battery cells are connected in series, the rated voltage is set to 280.8V, and the maximum voltage v1 is 327.6V.

  The plug unit 31 includes a plug receptacle (socket) (not shown) provided between the first assembled battery 32 and the second assembled battery 33, and a service plug 34 that is detachably attached to the plug receptacle. Yes. In a state where the service plug 34 is attached to the plug receptacle, the first assembled battery 32 and the second assembled battery 33 are energized to generate a voltage across the high voltage battery 12. On the other hand, in the state where the service plug 34 is detached from the plug receptacle, the energization of the first assembled battery 32 and the second assembled battery 33 is cut off, and no voltage is generated between both ends of the high voltage battery 12.

  Therefore, at the time of inspection work or maintenance work, the service plug 34 is detached from the plug receptacle by the operator, whereby the high voltage circuit in the battery box 20 is shut off. Thereby, the safety of the worker is ensured. In addition, although the high voltage circuit in the battery box 20 is cut off by the relay unit 24 when the vehicle is not in operation, in addition to this, the service plug 34 is detached so that the inside of the battery box 20 can be used even in an emergency such as a vehicle accident. It is possible to reliably cut off the high voltage circuit.

  The high voltage battery 12 is provided with a fuse 35 positioned between the plug unit 31 and the second assembled battery 33 for the purpose of protecting the high voltage circuit. The fuse 35 prevents an excessive current from flowing through the high voltage circuit in the battery box 20.

  FIG. 2 is a schematic diagram showing a state in which a leakage occurs in the battery pack in the high voltage circuit as a comparative example. 2, the same members as those shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted. FIG. 3 is a schematic diagram showing a state in which leakage occurs in the battery pack in the high voltage circuit shown in FIG.

  In the battery pack 41 shown in FIG. 2, the plug unit 31 is provided at the center of the high voltage battery 12. Therefore, the first assembled battery 42 and the second assembled battery 43 provided on both sides of the plug unit 31 are formed so as to generate substantially the same rated voltage. For example, when the rated voltage of the high voltage battery 12 is set to about 330 V using the same battery cell as in the example shown in FIG. 1, the maximum voltage u1, of the first assembled battery 42 and the second assembled battery 43 is set. Each of u2 is about 193V, and is set to maximum voltages u1 and u2 exceeding the upper limit value of the safety voltage.

  As described above, when the maximum voltage u2 of the second assembled battery 43 is set to be larger than the upper limit value of the safety voltage, the side where the relay unit 24 is not provided when the battery pack 41 is leaked. In this case, a large potential difference may occur between the high voltage circuit and the vehicle body. That is, as shown in FIG. 2, when the other end side (second assembled battery 43 side) of the plug unit 31 in the battery pack 41 leaks from the vehicle body, the voltage of the second assembled battery 43 increases the voltage. A potential difference exceeding the upper limit value of the safety voltage is generated between the voltage circuit and the vehicle body. In that case, even if the relay unit 24 and the plug unit 31 are opened during inspection work or maintenance work, the potential difference generated between the high voltage circuit and the vehicle body cannot be blocked. For this reason, the safety of the worker cannot be sufficiently ensured.

  On the other hand, in the high voltage circuit shown in FIG. 1, the maximum voltage v2 of the second assembled battery 33 is set to a safe voltage. For this reason, as shown in FIG. 3, even if the other end side (second assembled battery 33 side) of the plug unit 31 in the battery pack 21 leaks from the vehicle body, the relay unit 24 is provided. A potential difference exceeding the upper limit value of the safe voltage does not occur between the high voltage circuit and the vehicle body on the non-connected side. Therefore, it is possible to sufficiently ensure the safety of the operator without providing an opening / closing means such as a circuit interruption relay for opening / closing the power supply line 25b between the second assembled battery 33 and the output terminal 22b on the other end side. it can.

  Further, in the high voltage circuit shown in FIG. 1, if one end side (first assembled battery 32 side) of the plug unit 31 in the battery pack 21 leaks from the vehicle body, the first assembled battery 32 Due to the voltage, a potential difference exceeding the upper limit value of the safety voltage is generated between the high voltage circuit and the vehicle body on the side where the relay unit 24 is provided. In that case, the potential difference generated between the high voltage circuit and the vehicle body can be cut off by opening the relay unit 24 and the plug unit 31 at the time of inspection work or maintenance work.

  As described above, in the battery pack 21 shown in FIG. 1, the relay unit 24 is provided by shifting the plug unit 31 to the side where the relay unit 24 is not provided from the position of the intermediate potential of the high voltage battery 12. The maximum voltage v2 of the second assembled battery 33 arranged on the non-side is set to a safe voltage. As a result, even if a leakage occurs in the battery pack 21, a potential difference exceeding the upper limit value of the safe voltage occurs between the high voltage circuit and the vehicle body on the side where the relay unit 24 is not provided. Can be prevented. Therefore, it is possible to sufficiently ensure the safety of the operator without providing a circuit interruption relay between the second assembled battery 33 and the other end side output terminal 22b, and the battery pack can be obtained by omitting the circuit interruption relay. 21 can be reduced in size and cost.

  Further, for example, by setting a voltage that does not become a dangerous voltage defined in the UL standard, that is, a direct voltage of 60 V or less as a safety voltage, the battery pack 21 can be manufactured in accordance with the UL standard. Thereby, the reliability of the battery pack 21 can be ensured.

  Needless to say, the maximum voltage v0 of the high-voltage battery 12 can be set arbitrarily. However, when the plug unit 31 is provided at the center of the high-voltage battery 12 as shown in FIG. 2, both the first assembled battery 42 and the second assembled battery 43 exceed the upper limit value of the safe voltage. It is preferable that the maximum voltage v0 of the high-voltage battery 12 is set so that the maximum voltages u1 and u2 are set. That is, the present invention is suitable for the battery pack 21 including the high-voltage battery 12 that generates the maximum voltage v0 that is greater than twice the upper limit value of the safe voltage (for example, 120V).

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, in the above embodiment, the battery pack 21 to which the present invention is applied is mounted on an electric vehicle. However, the battery pack to which the present invention is applied to other vehicles such as a hybrid vehicle having an electric motor for traveling. 21 may be mounted.

  In the above embodiment, the relay unit 24 is provided on the positive electrode side of the high voltage battery 12. However, the relay unit 24 may be provided on the negative electrode side of the high voltage battery 12. In this case, the plug unit 31 is provided on the positive electrode side with respect to the position of the intermediate potential of the high voltage battery 12. Furthermore, the configuration of the high voltage circuit including the battery pack 21 can be arbitrarily changed. For example, another relay for interrupting the high voltage circuit may be provided outside the battery pack 21.

10 Motor generator (electric motor)
12 High voltage battery (battery for driving)
20 Battery box (case body)
21 Battery pack (vehicle power supply)
22a One end side output terminal 22b The other end side output terminal 24 Relay unit (first opening / closing means)
31 Plug unit (second opening / closing means)
32 1st assembled battery 33 2nd assembled battery

Claims (2)

A power supply device for a vehicle that includes a traveling battery formed by connecting a plurality of single cells in series, and that supplies power to an electric motor for traveling,
One end side output terminal and the other end side output terminal are provided in a case body that accommodates the battery for traveling, and one end and the other end of the traveling battery are respectively electrically connected;
A plurality of the single cells connected in series, the first assembled battery on the one end side output terminal side and the second assembled battery on the other end side output terminal side constituting the traveling battery;
A first opening / closing means accommodated in the case body for opening / closing an electrical connection between the one end side output terminal and the first assembled battery;
The first battery pack and the second battery pack are provided between the first battery pack and the second battery pack so as to be positioned on the other end side of the intermediate potential position of the battery for traveling. Second opening and closing means for opening and closing an electrical connection with the battery,
A vehicular power supply apparatus, wherein the maximum voltage of the second assembled battery is set to a safe voltage.   2. The vehicle power supply device according to claim 1, wherein the safety voltage is a direct current of 60V or less.

Images