JP2010176999A - Battery system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily change the number of connected battery cells and efficiently arrange the battery cells in a limited space. <P>SOLUTION: A battery system includes a first battery box 1 containing a plurality of battery cells 11, a second battery box 2 containing a plurality of battery cells 11, and a connecting box 3 for connecting the first battery box 1 and the second battery box 2, the connecting box 3 includes a first connecting circuit 31 for electrically connecting to the first battery box 1, a second connecting circuit 32 for electrically connecting to the second battery box 2, an integrated connecting circuit 33 for electrically connecting the first connecting circuit 31 and the second connecting circuit 32, and an output part 34 outputting electric power of the first battery box 1 and/or the second battery box 2 from the integrated connecting circuit 33 to the outside. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a battery system using a plurality of battery cells, and more particularly to a modular battery system in which the number of battery cells connected can be easily changed.

  A battery system in which a large number of battery cells are stacked can be connected to battery cells in series to increase the output voltage. Therefore, it is used for applications that charge and discharge with a large current, such as power supplies for hybrid cars and electric vehicles. The This battery system is discharged with a very large current when accelerating the vehicle, and is charged with a considerably large current in a state such as regenerative braking. This battery system achieves a required output by connecting a large number of large-capacity battery cells in series and / or in parallel.

  However, the required output varies depending on the vehicle. Since the output of the battery system is adjusted by the number of connected battery cells, the size of the case in which the battery cell is built is determined by the number of outputs. For this reason, conventionally, it has been necessary to design the case of the battery system for each required use, and there has been a problem that it takes development cost and design time.

  Further, since the number of necessary battery cells increases as the battery system becomes higher in output, the case of the battery system also becomes larger accordingly, so securing the space for arranging the case has also been a problem. In particular, in a vehicle-mounted application, it is not easy to place a high-power battery system because the shape and position of the space that can be placed are limited.

JP 2007-234369 A

  The present invention has been made in view of such a background, and one object thereof is to provide a battery system in which the number of battery cells connected can be easily changed. Another object is to provide a battery system capable of efficiently arranging battery cells in a limited space.

Means for Solving the Problems and Effects of the Invention

  In order to achieve the above object, according to the battery system of the present invention, the first battery box 1 incorporating a plurality of battery cells 11, the second battery box 2 incorporating a plurality of battery cells 11, and the first A connection box 3 for connecting the one battery box 1 and the second battery box 2, and the connection box 3 includes a first connection circuit 31 for electrically connecting to the first battery box 1. A second connection circuit 32 for electrically connecting to the second battery box 2, an integrated connection circuit 33 for electrically connecting the first connection circuit 31 and the second connection circuit 32, and the integration. An output unit 34 is provided for outputting the power of the first battery box 1 and / or the second battery box 2 from the connection circuit 33 to the outside. Thereby, by preparing a plurality of battery boxes and collecting the outputs of these battery boxes in one connection box 3 and connecting them in parallel or in series, the battery capacity can be easily improved. That is, it is possible to respond by changing the number of battery boxes connected without preparing battery boxes of different sizes according to the required specifications. In addition, by dividing the battery box into a plurality of parts, it is not necessary to arrange them in the same place, and it is possible to integrate the battery boxes positioned separately in the connection box 3, and into a limited space. Efficient placement is facilitated.

  In the battery system according to the second aspect, the connection terminals of the first connection circuit 31, the second connection circuit 32, and the integrated connection circuit 33 in the battery box are positive terminals 311, 321, 331, respectively. The negative terminals 312, 322, and 332 are on the same plane, and the positive terminals 311, 321, 331, and the negative terminals 312, 322, 332 are arranged at different horizontal planes. The positive terminals 311, 321, 331 and the negative terminals 312, 322, 332 can be connected to each other by a metal flat bus bar 4. Thereby, when wiring inside the connection box 3, the connection of the positive terminals 311, 321 and 331 to be connected and the negative terminals 312, 322 and 332 can be connected on the same plane. Further, by providing a difference in altitude between the positive electrode and the negative electrode, there is no short circuit even if these are crossed, and wiring can be performed safely even if a bare metal flat bus bar 4 is used. In this way, an inexpensive flat bus bar 4 can be used, and erroneous wiring with a different polarity can be physically avoided, so that safety and workability are improved.

  Furthermore, according to the battery system which concerns on a 3rd side surface, the said flat bus bar 4 can be comprised by combining several flat plate by screwing. Thereby, the flat plate bus bar of a desired pattern can be comprised by joining the flat plate of various patterns by screwing.

  Further, according to the battery system according to the fourth aspect, each battery box is provided with a connecting mechanism for the exhaust gas duct 17 on one side face, and the first battery box 1 and the second battery box 2 are connected to each other. It is possible to place the connection box 3 on the upper surface so as to be close to the surface opposite to the surface on which the duct connection mechanism is provided. . As a result, the exhaust gas duct 17 can be connected on one surface, and the wiring between each battery box and the connection box 3 can be performed on the other surface side. As a result, the battery system can be easily assembled.

  Furthermore, according to the battery system according to the fifth aspect, the connection box 3 is a relay capable of switching on / off the electrical connection of at least some of the battery boxes to be connected. Built-in. This makes it possible to switch the connection state of the battery box by turning the relay ON / OFF, change the output by changing the number of connections, or keep the output constant while using some battery boxes. However, it is possible to change the battery box to be used and disconnect the problematic battery box.

It is a perspective view which shows the external appearance of the battery system which concerns on embodiment of this invention. FIG. 2 is a vertical sectional view of the battery system of FIG. 1. It is a horizontal sectional view of a connection box. It is a perspective view which shows the inside of the connection box of FIG. It is a horizontal sectional view of the battery box of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a battery system for embodying the technical idea of the present invention, and the present invention does not specify the battery system as follows. Moreover, the member shown by the claim is not what specifies the member of embodiment. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing.

An example in which a battery system according to an embodiment of the present invention is applied to an in-vehicle battery system will be described below with reference to FIGS. In these drawings, FIG. 1 is a perspective view showing the appearance of the battery system, FIG. 2 is a vertical sectional view of the battery system of FIG. 1, FIG. 3 is a horizontal sectional view of a connection box, and FIG. FIG. 5 is a perspective view showing the inside of the box, and FIG. 5 is a horizontal sectional view of the battery box shown in FIG. In the battery system 100 shown in these drawings, the first battery box 1, the second battery box 2, and the connection box 3 are sequentially fixed in a stacked state.
(Battery box)

  The first battery box 1 and the second battery box 2 each contain a large number of battery cells 11. In the example of FIG. 2, the first battery box 1 and the second battery box 2 are the same, so the first battery box 1 will be described below as an example. Different configurations may be employed for the first battery box and the second battery box. For example, the second battery box may have fewer battery cells than the first battery box. Thus, the form of the battery box to be used can be changed as appropriate according to the required specifications.

  Each battery box has a plurality of battery cells 11 arranged vertically as shown in the vertical sectional view of FIG. 2, and a battery block electrically connected in series or in parallel to control charging / discharging of each battery cell 11. The battery control unit 12 is provided inside. The battery control part 12 detects the temperature and voltage of each battery cell 11, and controls charging / discharging of each battery cell 11 based on these temperature and voltage detection signals. The battery control unit 12 is disposed on one side of the upper surface of the battery block as shown in the vertical cross-sectional view of FIG.

  In an in-vehicle battery system, a high voltage for driving a motor and a low voltage for driving such as an electrical component driven by a conventional in-vehicle battery (12 V in this example) are required. Therefore, in the example shown in the horizontal sectional view of FIG. 5, the battery control unit 12 includes the high voltage circuit 13 and the low voltage circuit in order to appropriately manage the voltage obtained from the battery block separately for the high voltage and the low voltage. 14 and it is divided.

  The high voltage circuit 13 includes power system components, and is connected to a voltage detection line for detecting the voltage of each battery cell 11, and controls charging / discharging of the battery according to these voltages. On the other hand, the low voltage circuit 14 is connected to a temperature detection line for detecting the temperature of each battery cell 11, and monitors these temperatures. Further, a low voltage output terminal to the 12V signal line on the vehicle side and a control signal terminal are provided outside. The high voltage circuit 13 and the low voltage circuit 14 are insulated. Further, since the power system components mounted on the high voltage circuit 13 generate a large amount of heat, the reliability of control by the low voltage circuit 14 can be enhanced by separating these heat generating members from the low voltage circuit 14. On the other hand, the positive and negative outputs of the high voltage circuit 13 and the positive and negative outputs of the low voltage circuit 14 are connected to the connection box 3 side via output cables. In addition to the configuration in which both the control system signal voltage and the power system output voltage are sent to the connection box, only the power system output voltage is sent to the connection box, and the control system signal voltage is sent directly to the vehicle side. It is good also as a structure.

As shown in the perspective view of FIG. 1, the external appearance of the battery box is a box shape having a rectangular upper surface. Further, a vertically projecting flange 15 is provided on the side surface in the longitudinal direction so that it can be easily fixed when mounted on a vehicle. A screw hole is opened in the flange 15 to facilitate screwing using the screw hole. Further, cooling gas slits 16 for inflow and outflow of a gas duct for cooling gas for cooling the battery cell 11 are opened on the end face in the short direction. In this example, the cooling gas is allowed to flow to the side of the battery block, and the temperature of the battery cell 11 is absorbed by the cooling gas so that the cooling gas can pass through the cooling gap provided between the adjacent battery cells 11.
(Exhaust gas duct 17)

  Further, the battery box includes a fuse 18 and a service relay 19 that prevent overcurrent for safety. Further, on the side of the battery box, an exhaust gas duct 17 for discharging the gas discharged from the gas discharge valve of the battery cell 11 to the outside is drawn out. The battery cell 11 is provided with a gas discharge valve in order to prevent destruction in an abnormal state in which the internal pressure increases due to overcharge or overdischarge and to ensure safety. The gas discharge valve opens and exhausts gas when the internal pressure of the battery rises abnormally. For this reason, the exhaust gas duct 17 is arranged along the position of the gas exhaust valve of each battery cell 11 inside the battery box.

  The exhaust gas duct 17 is preferably provided on the end face opposite to the end face provided with the cooling gas slit 16. This is for isolating the cooling gas and the exhaust gas and for improving the efficiency of piping work for each gas. The first battery box 1 and the second battery box 2 are stacked in the same posture so that the surface provided with the exhaust gas duct 17 and the surface provided with the cooling gas slit 16 are aligned as shown in FIG. . This is preferable because the exhaust gas ducts 17 and the cooling gas slits 16 can be connected together on the same surface.

  In this example, the battery cell 11 is a lithium ion secondary battery. However, the battery cell is not specified as a lithium ion secondary battery, and any battery that can be charged, such as a nickel metal hydride battery, can also be used. In the battery cell 11, an electrode body in which positive and negative electrode plates are stacked is housed in an outer can, filled with an electrolyte solution, and hermetically sealed. The outer can is formed into a square cylinder that closes the bottom, and the upper opening is airtightly closed with a sealing plate. The outer can is a deep drawn metal plate such as aluminum or aluminum alloy, and the surface has conductivity. The battery cells 11 to be stacked are formed into thin squares. The sealing plate is also made of a metal plate such as aluminum or aluminum alloy. In this sealing plate, positive and negative electrode terminals are fixed to both ends via a terminal holder.

In this example, a rectangular battery cell is used. However, the present invention is not limited to this, and it is needless to say that a cylindrical battery, a polymer battery, or the like can be used as a battery cell.
(Connection box 3)

  The connection box 3 is a member that is connected to each of the first battery box 1 and the second battery box 2 to integrate and output the outputs from these battery boxes. As shown in the perspective view of FIG. 1, the outer shape of the connection box 3 is a box shape whose upper surface is a square shape. In the example of FIGS. 1 and 2, the connection box 3 is fixed on the upper surface of the second battery box 2. Bolts or fastening bands can be used for fixing.

As shown in FIGS. 3 and 4, the connection box 3 is connected to the first battery box 1 and receives the output of the first battery box 1. The connection box 3 is connected to the second battery box 2 and connected to the second battery box 2. The second connection circuit 32 that receives the output of the two-battery box 2 and the integrated connection circuit 33 that integrates the outputs of the first connection circuit 31 and the second connection circuit 32 are incorporated.
(First connection circuit 31)

  Since the first connection circuit 31 and the second connection circuit 32 have basically the same configuration except for the target battery box, the first connection circuit 31 will be described as an example here. The first connection circuit 31 is connected to the high voltage circuit 13 and the low voltage circuit 14 of the first battery box 1 and receives necessary power and signals. Specifically, the battery block output, battery voltage, battery temperature, service relay switching information, charge / discharge current amount detected by a current sensor, contact welding information, and the like. The first connection circuit 31 includes a positive terminal 311 and a negative terminal 312 for supplying the voltage of the first battery box 1 to the connection box 3 side. The positive electrode terminal 311 and the negative electrode terminal 312 are different in height.

The height difference is a distance that can ensure sufficient insulation even when metal bus bars intersect. In particular, when the flat bus bar 4 is connected by screwing as will be described later, the height is set so that the positive and negative bus bars 41 and 42 do not come into contact with each other by considering the increase in thickness due to screwing. This is set according to the thickness of the screw to be used, but is preferably 8 mm to 70 mm, more preferably 10 mm to 50 mm. (Confirmation required)
(Bus bar 4)

The terminals are connected by a flat bus bar 4. The flat bus bar 4 is composed of a metal plate. Moreover, the flat bus bar 4 can also be configured by combining a plurality of plates. In the example of FIGS. 3 and 4, a straight plate, a U-shaped plate, an L-shaped plate, or the like is joined by screwing to form a flat-plate bus bar having a desired pattern. According to this configuration, it is possible to construct various patterns of flat bus bars without preparing a dedicated pattern bus bar, which is advantageous in terms of cost.
(Integrated connection circuit 33)

  The integrated connection circuit 33 is a circuit for connecting the voltages from the first connection circuit 31 and the second connection circuit 32 in parallel, integrating them, and outputting power and signals to the outside. The integrated connection circuit 33 is connected to an output unit 34 having a terminal for taking out an output to the outside. If necessary, a safety circuit such as a fuse is provided.

In the circuit example of FIG. 3, the integrated connection circuit 33 is arranged in the lower stage, and the first connection circuit 31 and the second connection circuit 32 are arranged in the upper stage. Thus, if the connection circuit is arranged in parallel on one side and the integrated connection circuit 33 is arranged on the other side, the distance to be connected between each connection circuit and the integrated connection circuit 33 can be shortened, that is, the bus bar. 4 can be shortened. This is preferable from the viewpoint of reducing material costs and avoiding short circuits. In the example of FIG. 3, when the first connection circuit 31 and the second connection circuit 32 are arranged side by side, they are arranged so as to be asymmetrical, in other words, without matching the height. In this manner, the connection circuit is intentionally arranged asymmetrically, so that the first connection circuit 31 and the second connection circuit 32 can be distinguished, which contributes to avoiding unintentional miswiring.
(Output unit 34)

  In the example of FIG. 1, as the output portion 34, a notch-shaped step is provided at the edge from the upper surface to the front surface, and the output terminal is exposed at this portion. In the example of FIG. 1, in order to avoid unintentional conduction between the positive and negative electrodes, the positive electrode side 341 and the negative electrode side 342 are separated, and the positive electrode side 341 has three terminals of total plus, high voltage component 1 plus, and high voltage component 2 plus. Is provided. Further, the negative electrode side 342 is provided with three terminals of total minus, high voltage component 1 minus, and high voltage component 2 minus. Here, the high voltage component 1 is a DC / DC converter, and the high voltage component 2 is an emergency charger.

  As shown in the vertical sectional view of FIG. 2, the connection box 3 is positioned on the upper surface of the second battery box 2 so as to be close to the side where the battery control unit 12 is disposed inside the battery box. Thereby, harnesses, such as a cable withdraw | derived from the battery box to the connection box 3, can be wired at a short distance, and workability | operativity also improves.

  As described above, the first connection circuit 31 and the second connection circuit 32 have the same heights of the positive terminals 311 and 321 and the negative terminals 312 and 322, respectively. Further, the integrated connection circuit 33 also matches the height of the input side terminal to which the positive terminal 331 and the negative terminal 332 are connected to that of the first connection circuit 31. For this reason, when connecting the positive terminals, the terminals 311, 321, and 331 to be connected are arranged at the same height, and therefore can be easily connected by connecting the flat bus bar 4. Similarly, since the height of the negative electrode terminal is also uniform at each terminal 312, 322, 332, connection on the negative electrode side is easy. Further, since the positive terminals 311, 321, 331 and the negative terminals 312, 322, 332 have different heights, the positive terminal connecting bus bar 41 and the negative terminal connecting bus bar 42 do not contact each other even if they intersect. This greatly contributes to labor saving of wiring work. In particular, since the bus bar is made of metal and the conductive portion is exposed, unintended conduction is likely to occur. For this reason, it is not easy to cross the positive and negative bus bars, and there is a risk of short circuit. On the other hand, in the configuration of the present embodiment, the height is positive and negative, the same plane, and the positive and negative heights are different, so that crossing arrangement is possible, and the safety and workability can be improved. Benefits.

  In this way, the necessary battery cells 11 are divided and stored in a plurality of battery boxes, and these battery boxes are integrated by the connection box 3, whereby the battery capacity can be easily adjusted. As a result, it is possible to flexibly meet the required specifications such as connecting many battery boxes for high voltage and using few battery boxes for low voltage. In other words, the battery system design work can be greatly saved because it can be handled by changing the number of battery boxes connected without preparing battery boxes of different sizes according to the required specifications.

  Further, by arranging the battery box to be divided into a plurality of wirings, it is possible to eliminate the need to arrange them in the same place. That is, in the example of FIG. 1, the battery box and the connection box 3 are laminated and integrated. However, the present invention is not limited to this configuration, and battery boxes arranged at different locations can be integrated by the connection box by cable connection. Efficient placement in a limited space is facilitated. This is particularly advantageous for in-vehicle applications subject to restrictions on the mounting space.

  Furthermore, in the above example, a configuration in which two battery boxes are connected in parallel is adopted, but it is needless to say that a form in which the battery boxes are connected in series is also possible. In addition, it is possible to combine three or more battery boxes to one connection box to collect outputs. In addition, a form in which a plurality of connection boxes are connected can also be used.

  In addition, the connection box 3 can incorporate a relay capable of switching ON / OFF of the electrical connection of the battery box to be connected. By switching the connection state of the battery box by ON / OFF of the relay, the number of connections can be changed to change the output voltage, and the same battery system can cope with different voltages. In addition, when only a part of battery boxes are used at a constant output, the battery box can be used for backup. That is, when an abnormality occurs, the problematic battery box can be disconnected and driven with a spare battery box, and reliability can be improved.

  As shown in FIGS. 1 and 2, the connection box 3 is desirably placed so as to be close to the surface opposite to the surface on which the coupling mechanism of the exhaust gas duct 17 is provided. The exhaust gas duct 17 can be connected on one side, and the wiring between each battery box and the connection box 3 can be done on the other side. This is because it is easy to assemble.

  The battery system according to the present invention can be suitably used as an in-vehicle battery system.

DESCRIPTION OF SYMBOLS 100 ... Battery system 1 ... 1st battery box 2 ... 2nd battery box 3 ... Connection box 4 ... Bus bar 11 ... Battery cell 12 ... Battery control part 13 ... High voltage circuit 14 ... Low voltage circuit 15 ... Flange 16 ... For cooling gas Slit 17 ... Exhaust gas duct 18 ... Fuse 19 ... Service relay 31 ... First connection circuit 32 ... Second connection circuit 33 ... Integral connection circuits 311, 321, 331 ... Positive terminal 312,322,332 ... Negative terminal 34 ... Output 341: Positive electrode side 342 ... Negative electrode side 41 ... Bus bar for connecting positive electrode terminal 42 ... Bus bar for connecting negative electrode terminal

Claims (5)

A first battery box (1) containing a plurality of battery cells (11);
A second battery box (2) containing a plurality of battery cells (11);
A connection box (3) for connecting the first battery box (1) and the second battery box (2);
A battery system comprising:
The connection box (3)
A first connection circuit (31) for electrically connecting to the first battery box (1);
A second connection circuit (32) for electrically connecting to the second battery box (2);
An integrated connection circuit (33) for electrically connecting the first connection circuit (31) and the second connection circuit (32);
An output unit (34) for outputting the electric power of the first battery box (1) and / or the second battery box (2) from the integrated connection circuit (33) to the outside;
A battery system comprising: The battery system according to claim 1,
In the battery box, the connection terminals of the first connection circuit (31), the second connection circuit (32), and the integrated connection circuit (33) are respectively positive electrode terminals (311,321,331) and negative electrode terminals (312,322,332). Each on the same side,
And the positive electrode terminal (311,321,331) surface and the negative electrode terminal (312,322,332) surface are arranged at different horizontal plane heights,
A battery system characterized in that the positive terminals (311,321,331) and the negative terminals (312,322,332) are connected to each other by a metal flat bus bar (4). The battery system according to claim 1 or 2,
The battery system, wherein the flat bus bar (4) is configured by combining a plurality of flat plates by screwing. The battery system according to any one of claims 1 to 3,
Each battery box has an exhaust gas duct (17) coupling mechanism on one side,
The first battery box (1) and the second battery box (2) are stacked so that the surfaces provided with the duct coupling mechanism are the same surface, and the connection box (3) is further provided on the upper surface. The battery system is placed so as to be close to a surface opposite to the surface on which the duct coupling mechanism is provided. The battery system according to any one of claims 1 to 4,
The connection box (3) has a built-in relay capable of switching ON / OFF of the electrical connection of at least some of the battery boxes to be connected. .

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