JPH06223815A - Battery - Google Patents

Abstract

PURPOSE:To provide a battery which can be charged and discharged without risk of all fuses belonging to one block blowing even in case shortcircuit is formed in two places or more. CONSTITUTION:A battery group is formed by connecting single pieces of unit cells 3 or connecting parallel a plurality of ones 3 in series connection while a connecting means 14 is interposed, and a plurality of such battery groups are connected in series to form a battery, wherein fuses 16, 17 in connection with the unit cells are arranged on both sides while pinching the connecting means 14, and the rating of fuses on one side is made different from the rating of fuses 16, 17 on the other side. This allows performing charging and discharging of the battery even though external shortcircuiting has occurred in a plurality of places.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembled battery formed by assembling a plurality of high temperature secondary batteries such as sodium-sulfur batteries.

[0002]

2. Description of the Related Art An assembled battery is constructed by connecting a plurality of cells in series or in parallel. The internal structure of this assembled battery will be described with reference to FIG. 4 by taking a 50 kw class assembled battery as an example. In this assembled battery, first, three unit cells are connected in series, and a 50A fusing fuse 31 is connected to the plus side of each group of the series unit cells 30 to form a string 32.
Six strings 32 are connected to the parallel bus bar 33 to form a block 34, and 18 blocks 34 are connected in series to form a unit 35. Then, a plurality of units 35 are connected in series or in parallel to form sub-modules to form an assembled battery. 50 here
When the internal short circuit of the unit cell 30 occurs, the A blow fuse 31 is blown for safety.

[0003]

However, an external short circuit such as a ground fault may occur in the assembled battery, which may occur in two places as shown in FIG. In this case, since a current higher than the rated current flows through these fuses 31, all the fuses 31 in this block 34 are blown out. That is, the short-circuit current is first concentrated on the fuse 31a closest to the ground fault, and as a result, the fuse 31a is blown. Then, the short-circuit current will be shunted to the remaining fuses 31 connected to the parallel bus bar 33 together with the fuse 31a, but a current that greatly exceeds the rating of 50 A will flow to these fuses 31 one after another.
The fuses 31 of this block 34 are all blown. Therefore, in this case, the assembled battery is disconnected and charging / discharging becomes impossible.

The present invention has been made by paying attention to the problems existing in such a conventional technique, and the purpose thereof is to detect all the blocks even if a ground fault occurs at two or more places. An object of the present invention is to provide an assembled battery that can be charged and discharged without blowing a fuse.

[0005]

In order to achieve the above-mentioned object, the present invention further comprises a battery group in which a single battery or a plurality of battery cells connected in series are connected in parallel with a connecting means interposed between them. In an assembled battery that is connected, fuses for connecting to each unit cell are arranged on both sides of the connecting means, and the rating of each fuse on one side and the rating of each fuse on the other side are different. battery.

[0006]

With the above-mentioned structure, when a ground fault occurs at two or more locations, the short-circuit current flows intensively to the fuse on one side closest to the ground fault location, and the fuse is blown to cause the ground fault current. Loop is cut off. Then, the normal current is shunted to the remaining fuses to flow, and charging and discharging of the assembled battery are continued.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an assembled battery embodying the present invention will be described in detail below with reference to FIGS.

The outer shape of the assembled battery 1 is constituted by a heat insulating container 2. The heat insulating container 2 is composed of a side plate 5 which can be divided, a lid plate 6 arranged at the top and a bottom plate 7 arranged at the bottom. The heat insulating container 2 is vertically divided into four parts, which are stacked and completed as a container.

Inside the heat insulating container 2, a frame 1 is provided for each stage.
A unit 11 housed in 0 is arranged. Figure 2
As shown in FIG. 4, the unit 11 in the frame 10 is composed of 18 blocks 12 connected in series. In each block 12, six strings 13 are connected in parallel to a parallel bus bar 14 which is a connecting means. The string 13 includes three unit cells 3 connected in series and a low rating of 5
It is composed of a 0A blowout fuse 16 and a high rated 200A blowout fuse 17. 50A blown fuse 16
Is connected between the positive side of the unit cell 3 and the parallel bus bar 14 adjacent thereto, and the 200 A fusing fuse 17 is connected between the negative side of the unit cell 3 and the parallel bus bar 14 adjacent thereto. That is, each string 13 has two fuses 16 and 17 having different ratings on both sides thereof.

The reason why the low-rated fuse is set to 50 A is that it is determined based on the condition that the safety of the battery can be ensured even when an internal short circuit occurs and a follow current flows continuously. In addition, the reason why the high-rated fuse is set to 200 A is that the fuse is surely blown when a current flowing through each string 13 concentrates at one place in a ground fault state described later. That is, this fuse must have a low resistance and be blown with a resistance lower than 6 × 50 = 300 A calculated by multiplying the number of strings 13 of each block 12 by 50 A. However, the larger the fusing current, the smaller the fuse resistance, and the lower the internal resistance, the better the battery efficiency.
00A. In addition, both fuses 16 and 17
Is made of aluminum alloy, specifically A3003,
The material is AMSC alloy, A1050 or the like, but of course, other materials and standards may be used. One unit 11 is composed of a total of 324 single cells 3 of 3 × 6 × 18, and the four units 11 of each stage are electrically connected to each other to form a sub-module which is a single cell assembly. ing.

Next, the operation of the assembled battery 1 thus constructed will be described. For example, as shown in FIG. 3, it is assumed that the active material of the two unit cells 3 between two adjacent blocks 12 in the assembled battery 1 leaks and a ground fault occurs. That is, the ground fault current flows between the ground fault parts P and Q. In this case, as shown in FIG. 3, the current flowing through each string 13 is the 200A blown fuse 17 closest to the ground fault.
As a result, the fuse 17a is blown out. As a result, the string 13 including the ground fault portion P is cut off. Then, since the normal current is shunted to the remaining five 200A fusing fuses 17 and flows, 50A
The blow fuse 16 is not blown. Here 5
The number of 0A fusing fuses 16 is reduced from 6 to 5, but it is assumed that the rating of 50A is set so that even if the reduced 1 string 13 is shunted, it will not be blown. On the other hand, when an internal short circuit occurs in each cell 3, the 50 A blow fuse 16 of the string 13 including the cell 3 is blown. This is a 200A blown fuse 1
This is because the resistance of the 50 A blow fuse 16 is larger than that of 7.

With such a configuration, in the assembled battery 1 of this embodiment, even if a ground fault occurs at two or more locations, the 200A blow fuse 17 closest to the ground fault portion is simply blown and other fuses are blown. 16 and 17 do not melt. Of course, there is no possibility that the 50 A blow fuses 16 will blow out one after another. In addition, since the high-rated fuse connected to the negative side is the 200 A blowout fuse 17, the resistance is low and the efficiency of the assembled battery 1 is not significantly reduced.

The embodiment of the present invention has been described above.
The present invention can be implemented by being modified into other aspects. For example, in the above-described embodiment, the 50A blown fuse 16 is on the positive side of the unit cell 3, and the 200A blown fuse 17 is also on the positive side.
Was disposed on the negative side of the unit cell 3, but these may be disposed in reverse. Further, in the above embodiment, the low-rated fuse is set to 50 A, but any current value lower than the current destruction limit of the unit cell 3 may be used. The rated value of each fuse can be freely changed according to the scale of the assembled battery 1. Further, in the above embodiment, the unit 11 is composed of a total of 18 blocks 12, and each block 12 is composed of 6 blocks.
Although it was composed of the strings 13 of the book, the design change of these is free. Of course, the string 13
May be configured by connecting any number of unit cells 3 in series, and the unit cells 3 may be independent. Other connection means may not necessarily be parallel bus bars, etc. The present invention can be freely modified and implemented without departing from the scope of the invention.

[0014]

As described above, according to the present invention, the assembled battery in which the battery groups which are connected in parallel with the connecting means interposed are further connected in series is connected to each unit cell on both sides of the connecting means. Since fuses are installed and the rating of each fuse on one side is different from the rating of each fuse on the other side, all fuses will not be blown even if multiple locations are externally short-circuited. Therefore, there is an excellent effect that the assembled battery can be charged and discharged even if there are a plurality of external short circuits.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating an internal connection structure of an assembled battery that is an embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view illustrating the appearance of the assembled battery of the same embodiment.

FIG. 3 is a schematic view enlarging and explaining a main part of an internal connection structure of an assembled battery that is an embodiment of the present invention.

FIG. 4 is a schematic diagram illustrating an internal connection structure of a conventional assembled battery.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Assembly battery, 3 ... Single battery, 14 ... Parallel bus bar which is a connecting means, 16 ... Fuse 50A fusing fuse, 1
7, 17a ... 200A blown fuse which is a fuse.

Claims (1)

[Claims] 1. An assembled battery in which a battery group, in which a single cell or a plurality of single cells connected in series are connected in parallel with a connecting means interposed therebetween, is further connected in series, on both sides sandwiching the connecting means. An assembled battery in which a fuse to be connected to each unit cell is provided, and the rating of each fuse on one side is different from the rating of each fuse on the other side.