JP2025125064A - Battery pack system, battery module used in the battery pack system, and connector - Google Patents

Abstract

To provide a battery pack system that allows the electrical specifications such as voltage to be freely changed according to the application, and that can be efficiently arranged in various spaces, thereby increasing the degree of standardization of battery packs and also providing excellent maintainability.
[Solution] The battery module 2 has one or more storage units B1 housed inside a housing 20, and has terminal units 24A, 24B that serve as electrodes on the upper end surface 20a and lower end surface 20b of the housing, respectively. The multiple battery modules 2 are electrically connected via the terminal units, and a connecting unit 25 is provided on a side surface 20c of the housing 20, which connects two battery modules 2 with the side surfaces 20c of the housing facing each other.
[Selected Figure] Figure 1

Description

The present invention relates to a battery pack system equipped with a power storage unit.

In recent years, battery packs mounted on electric vehicles have become known (see, for example, Patent Document 1). However, the required voltage and other electrical specifications of electric vehicles vary depending on the model and manufacturer. The required voltage and other electrical specifications of electrically powered devices other than electric vehicles also vary. This makes it difficult to standardize battery packs, which increases costs.

In addition, battery packs for conventional electric devices have typically been roughly rectangular parallelepiped-shaped battery packs arranged vertically and horizontally. The space within the electric device in which these battery packs are installed is also generally rectangular, and the electrical specifications that can be installed are limited by the capacity of that space. Furthermore, battery pack specifications must be optimized for each application and space, making it difficult to standardize battery packs for these reasons.

In addition, the battery packs are arranged vertically and horizontally and securely fastened with belts or other fasteners to prevent interference even when subjected to vibrations, but there was also the issue of a lack of maintenance capabilities, such as inspection and replacement, when some of the battery packs malfunction.

Patent Publication No. 2022-115495

In light of the above situation, the present invention aims to solve the problem of providing a battery pack system that allows electrical specifications such as voltage to be freely changed to suit the application, and that can be efficiently placed in a variety of spaces, thereby increasing the degree of standardization of battery packs and also providing excellent maintainability.

That is, the present invention includes the following inventions.
(1) A battery pack system comprising a plurality of battery modules connected together, wherein the battery module has one or more storage units housed inside a housing, and terminal portions serving as electrodes on the upper and lower end surfaces of the housing, the plurality of battery modules being electrically connected via the terminal portions, and a connecting portion being provided on a side surface of the housing to connect two of the battery modules together with the sides of the housing facing each other.

With this configuration, the power storage units of multiple battery modules are connected, and electrical specifications such as output voltage can be changed by increasing or decreasing the number of battery modules depending on the voltage required for each electrically powered device, such as an electric vehicle. As a result, the battery pack system can be applied to a variety of electrically powered devices, making it easy to increase the degree of standardization. Furthermore, because the connecting parts allow two battery modules to be connected with their housing sides facing each other, they can be maintained in a stable position as designed, compared to conventional methods of fastening them with bands or the like. This allows for efficient and stable placement in a variety of spaces, not just cubic spaces, thereby increasing the degree of standardization of the battery pack. Furthermore, by releasing the connecting parts, some battery modules can be easily separated, making maintenance easier.

(2) The battery pack system described in (1), wherein the housing of each battery module has a polygonal prism shape with its upper and lower end surfaces. This configuration allows the battery modules to be connected to each other using the connecting parts in a more diverse and stable manner, further increasing the degree of commonality of battery packs.

(3) The battery pack system described in (2), wherein the connecting portion has an engaging portion and an engaged portion that are structured to engage with each other, and are provided on a pair of flat side surfaces of the prismatic housing that are symmetrical about the axis. This configuration allows the battery modules to be connected together in a more stable position, facilitating attachment and detachment, and improving maintainability.

(4) The battery module described in (3), wherein the engaging portion and the engaged portion comprise a dovetail-shaped or T-groove-shaped recess extending in the axial direction, and a protrusion shaped to fit into the recess and engage with the groove so as to be movable relative to the groove in the axial direction. This configuration allows the battery modules to be connected together in a more stable position, and also makes attachment and detachment easier, further improving maintainability.

(5) A battery pack system including a coupler that electrically connects the two battery modules connected by the connecting portion, the coupler having a pair of connectors connected to the upper or lower end surfaces of the battery modules and having connecting terminals electrically connected to the terminal portions provided on those surfaces, and a connecting wire provided between the connectors and electrically connecting the connecting terminals. With this configuration, battery modules connected laterally by the connecting portion can be electrically connected to each other through the coupler, allowing for more diverse arrangements of battery modules and more efficient placement in a variety of spaces.

(6) A battery pack system according to any one of (1) to (5), wherein the battery module includes a first positive terminal and a first negative terminal as the electrodes on the upper end surface, a second positive terminal and a second negative terminal as the electrodes on the lower end surface, a positive side path portion for flowing current between the first positive terminal and the second positive terminal, a negative side path portion for flowing current between the second negative terminal and the first negative terminal, and a switching circuit for switching connection states of the current path in at least one of the positive side path portion and the negative side path portion, including an insertion state in which the power storage unit is inserted into the current path and a removal state in which the power storage unit is removed from the current path.

With this configuration, the number of series connections of the power storage units can be dynamically changed using a switching circuit to change the output waveform, making it possible to adapt the voltage waveform required for each electrically powered device and further increasing the degree of standardization.

(7) A battery module for use in a battery pack system described in any one of (1) to (6), in which one or more power storage units are housed inside a housing, the housing has terminal portions that serve as electrodes on the upper and lower end surfaces, the multiple battery modules can be electrically connected via the terminal portions, and a connecting portion is provided on a side surface of the housing to connect two of the battery modules with the side surfaces of the housing facing each other.

(8) A coupler used in the battery pack system described in any one of (1) to (6) that electrically connects two battery modules connected by the connecting portion, the coupler comprising a pair of connectors connected to the upper end surfaces or lower end surfaces of the battery modules and having connecting terminals electrically connected to the terminal portions provided on those surfaces, and a connecting wire provided between the connectors that electrically connects the connecting terminals.

This invention makes it possible to freely change electrical specifications such as voltage to suit the application, and to efficiently arrange battery packs in a variety of spaces, thereby increasing the degree of standardization of battery packs and providing a battery pack system that is also easy to maintain.

FIG. 2 is an explanatory diagram showing an example in which a plurality of battery modules are connected together according to an embodiment of the present invention. FIG. 2 is a perspective view schematically showing the appearance of a battery module. FIG. FIG. 3 is an explanatory diagram showing a power storage unit inside a housing of a battery module. FIG. 10 is an explanatory diagram showing a state in which a plurality of battery modules are connected in the horizontal direction at connecting portions. FIG. 2 is a vertical cross-sectional view showing the housing structure of the battery module. FIG. 2A is a perspective view showing a coupler, and FIG. 2B is a longitudinal cross-sectional view. FIG. 10 is an explanatory diagram showing a modified example of the terminal portion. FIG. 1 is an explanatory diagram showing an example of the configuration of a battery pack system formed by connecting a plurality of battery modules. FIG. 2 is a perspective view showing the external appearance of the end module as viewed from the top side. FIG. 2 is a perspective view showing the external appearance of the end module as viewed from the bottom side. FIG. 2 is a vertical cross-sectional view showing the housing structure of the end module. FIG. 2 is a perspective view of the appearance of a parallelization module. FIG. 10 is a plan view of the parallelization module. FIG. 2A is an explanatory diagram showing a coupler that couples parallel modules, and FIG. 2B is an explanatory diagram showing a state in which a plurality of parallel modules are coupled by the coupler. 10A and 10B are explanatory diagrams showing modified examples of the series block. FIG. 10 is a block diagram illustrating an example of an electrical configuration of the series block illustrated in FIG. 9 . FIG. 3 is a schematic circuit diagram for explaining the configuration of a unit module. FIG. 10 is a conceptual circuit diagram showing an example of a unit module EM using a full bridge as a switching circuit. FIG. 10 is an explanatory diagram for explaining a parallel connection of series blocks.

Embodiments of the present invention will now be described with reference to the drawings. A battery pack system 1 according to the present invention is a system formed by connecting multiple battery modules 2. Figure 1 shows an example of a configuration (battery string) in which multiple battery modules 2 are connected.

The outer shape of the housing 20 of the battery module 2 is a polygonal prism with the upper end surface 20a and the lower end surface 20b being a regular hexagonal prism. As shown in Figure 4, the battery module 2 houses one or more battery cells as a power storage unit B1 inside the housing 20.

2 and 3, terminal portions 24A and 24B, which serve as electrodes, are provided on the upper end surface 20a and the lower end surface 20b of the housing 20, respectively, and multiple battery modules 2 are electrically connected via these terminal portions 24A and 24B. In this example, the terminal portions 24A and 24B comprise six annular electrodes, in order from the outer periphery: main electrode (positive) d1, main electrode (negative) d2, control power electrode (positive) d3, control power electrode (negative) d4, communication line electrode (positive) d5, and communication line electrode (negative) d6. These six annular electrodes are arranged concentrically around the central axis of the battery module 2 at intervals in the radial direction. The type, number, and arrangement of the electrodes are not limited to this example. For example, by making communication wireless, it is possible to omit communication line electrodes d5 and d6 and reduce the number of electrodes.

By arranging the electrodes in a concentric ring shape as in this example, it is possible to electrically connect the battery modules 2 connected to either side of the polyhedron using the same connector 6, described below, which is efficient. However, arranging the electrodes in a ring shape is not essential. For example, as shown in Figure 8, even if the electrodes d1 to d6 are provided discretely at corresponding positions on each side, the same effect as with the ring-shaped electrodes can be achieved by arranging the electrodes d1 to d6 of the connector 6 in a corresponding position. Furthermore, it is preferable that the electrodes d1 to d6 of the terminal portions 24A and 24B have a touchproof structure.

As shown in Figure 6, holes 27 are provided at the center of the upper end surface 20a and lower end surface 20b of the housing 20, connecting the interior and exterior spaces of the housing 20. These upper and lower holes 27 allow a cooling refrigerant such as air to circulate through the gaps within the housing 20, as indicated by the arrows in the figure, thereby enabling heat inside each housing 20 to be dissipated to the outside.

In addition, a connecting portion 25 is provided on the side surface 20c of the housing 20, connecting the two battery modules 2 with the side surfaces of the housing facing each other. As shown in Figures 2 and 3, the connecting portion 25 has an engaging portion 70 and an engaged portion 71 that are structured to engage with each other and are provided on a pair of side surfaces 20c that are symmetrical about the axis among the multiple flat side surfaces 20c of the prismatic housing 20.

The structure of the engaging portion 70 and the engaged portion 71 is not particularly limited, but a preferred example, as in this example, is one in which the engaging portion 70 has a dovetail-shaped or T-groove-shaped recess extending in the axial direction (vertical direction), and the engaged portion 71 has a convex portion shaped to fit into the engaging portion 70 and engages with the recess so that it can move relative to the axial direction. This allows for easy connection/disconnection by sliding up and down, and also allows for connection by flipping the parts upside down.

When the housing 20 is hexagonal prism-shaped as in this example, it is preferable to provide such connecting portions 25 alternately so that the engaging portions 70 and the engaged portions 71 are aligned on two adjacent side surfaces. This allows the opposing side surfaces to be firmly connected together through the engaging portions 70 and the engaged portions 71 when multiple battery modules 2 are arranged densely horizontally as shown in Figure 5. While connecting portions 25 are provided on each side surface 20c, they do not need to be provided on all side surfaces.

In addition, vertical connecting portions 26 that connect the two battery modules 2 vertically are provided on the upper end surface 20a and lower end surface 20b of the housing 20. The structure of the vertical connecting portions 26 is not particularly limited, and various configurations are possible, such as one in which an engaging portion and an engaged portion are provided on the housing 20, or one in which the terminal portions 24A, 24B are connected to each other as male and female terminals.

When battery modules 2 are connected vertically via the vertical connectors 26, the opposing terminals 24A, 24B are also electrically connected to each other. This vertical connection also enables battery module 2 arrangements (battery strings 3) such as those shown in Figures 16(a) and 16(b). Furthermore, the aforementioned through-holes 27 on the opposing upper and lower end faces 20a, 20b of vertically connected battery modules 2 also face each other at the same position (center), allowing refrigerant to be transferred between battery modules 2 and circulating through multiple battery modules 2, as indicated by the dashed arrows in the figure.

In this example, when the battery modules 2 are connected horizontally, as shown in FIG. 1, a connector 6 is provided between two adjacent battery modules 2 connected horizontally by the connecting portion 25 described above, to electrically connect these two battery modules 2 to each other. Specifically, the connector 6 is connected to each upper end surface 20a (or lower end surface 20b) of each battery module 2 and has a pair of connectors 61 on the opposing surface (connecting surface 61a) with connecting terminals 60A electrically connected to the terminal portions 24A (24B) provided on the upper end surface 20a (or lower end surface 20b) of the battery module 2, and a connecting portion 62 provided between the connectors 61 and incorporating connecting wires 60C that electrically connect the connecting terminals 60A to each other.

Specifically, the connecting terminal 60A corresponds to the terminal portion 24A and has, in order from the outer periphery, a total of six annular electrodes: a main electrode (positive) d1, a main electrode (negative) d2, a control power electrode (positive) d3, a control power electrode (negative) d4, a communication line electrode (positive) d5, and a communication line electrode (negative) d6. Each of the electrodes of each connector 61 is connected by a connecting wire.

The planar shape of each connector 61 of the coupler 6 is the same as the top end surface 20a of each battery module 2 to which it is connected (hexagonal in this example), and is provided with a connecting structure that engages with the vertical connecting portion 26 provided on the top end surface 20a. Various configurations are possible, such as those with engaging or engaged portions, or those in which the terminal portions 24A, 60A are connected to each other as male and female terminals.

By connecting the battery modules 2 using such connectors 6, it is possible to connect them in any direction by selecting from multiple side faces (in this example, six side faces at 60-degree intervals). This allows for free horizontal placement, making it possible to efficiently arrange multiple battery modules 2 even in a cylindrical space such as a car's spare tire storage space.

As shown in Figures 7(a) and 7(b), a through-hole 63 is provided in the center of the connection surface 61a of each connector 61, facing the position (center) of each of the above-mentioned through-holes 27 in the opposing upper end face 20a or lower end face 20b of the battery module 2. This through-hole 63 allows refrigerant to be transferred between the battery module 2 and the connector 6, and a refrigerant flow path 64 is provided inside the connector 6, which is made up of the connector 61 and the connecting portion 62, for refrigerant to flow in from one through-hole 63 and discharge from the other through-hole 63. This allows the connector 6 to receive refrigerant from one connected battery module 2, circulate it through the flow path 64, and then transfer it to the other battery module 2, while simultaneously dissipating heat trapped inside to the refrigerant.

We will now explain a more specific configuration example of a battery pack system 1 formed by connecting multiple battery modules 2 as described above.

For example, in the configuration example shown in FIG. 9 , an end module 4 is connected to one end of a battery string 3, in which multiple battery modules 2 are connected horizontally, and a paralleling module 5 is connected to the other end of the battery string 3. In this example, multiple battery modules 2 are connected two-dimensionally horizontally, but various other configurations are possible, such as two-dimensional connections vertically and horizontally as shown in FIGS. 16( a) and 16(b), or three-dimensional connections that combine these. A battery pack system is formed by connecting multiple series blocks 11, each consisting of a paralleling module 5, a battery string 3, and an end module 4, via the paralleling module 5. The end module 4 and paralleling module 5 basically have the same connection structure (connecting portion 25, specifically, engaging portion 70 and engaged portion 71) as the battery module 2, and are each detachable from the battery module 2 at the end of the battery string 3.

As shown in Figures 10 and 11, the external shape and size of the housing 40 of the end module 4 are substantially the same as those of the housing 20 of the battery module 2, with the upper end face 40a and lower end face 40b also having a polygonal prism shape, more specifically, the upper end face and lower end face are regular hexagonal prisms. However, unlike the battery module 2, no power storage unit is housed inside the housing 40.

As shown in Figure 10, the upper end surface 40a of the end module 4 is provided with a terminal portion 43A, similar to the upper end surface 20a of each battery module 2, and is electrically connected to the adjacent battery module 2 via the connector 6. Specifically, a total of six annular electrodes are provided, in order from the outer periphery: main electrode (positive) d1, main electrode (negative) d2, control power electrode (positive) d3, control power electrode (negative) d4, communication line electrode (positive) d5, and communication line electrode (negative) d6. The other lower end surface 40b does not have a terminal portion.

The upper end surface 40a is also provided with a similar vertical connecting portion 46 that connects to the vertical connecting portion 26 on the lower end surface 20b of the battery module 2. Various configurations are possible, such as those with an engaging portion or an engaged portion, or those in which the terminal portion 43A and the terminal portion 24B on the battery module 2 that connects to it are structured as male and female terminals that can be connected to each other. In this example, the connection is made by the connecting structure of the coupler 6.

In addition, a through-hole 47 is provided in the center of the upper end surface 40a, corresponding to the position (center) of the aforementioned through-hole 27 on the lower end surface 20b of the connectable battery module 2 and the position of the through-hole 63 of the connector 61 of the coupler 6, and allowing for the transfer of refrigerant between the battery module 2. As shown in Figure 12, a through-hole 48 is also provided in the lower end surface 40b, connecting the interior and exterior spaces of the housing 40.

This through hole 48 serves as an inlet for taking in refrigerant into the series block 11, or as an outlet for refrigerant from the series block 11, and is equipped with a filter 49. The end module 4 circulates cooling refrigerant, such as air, through the gaps within the housing 40 through these upper and lower through holes 47, 48. It is preferable to install a pump, such as a fan 490, inside the housing 40 of the end module 4 to force the refrigerant to circulate, as shown in Figure 12.

As shown in Figures 13 and 14, the external shape and size of the housing 50 of the parallelization module 5 are the same as the housing 20 of the battery module 2, and the upper end face 50a and lower end face 50b are also polygonal prism shapes, more specifically, the upper end faces and lower end faces are hexagonal prisms with regular hexagons. However, unlike the battery module 2, no power storage unit is housed inside the housing 50.

Terminal portions 53A, 53B are provided on the upper end surface 50a and lower end surface 50b of the paralleling module 5 for electrical connection between the battery modules 2 and the couplers 6, and are electrically connected to adjacent battery modules 2 through the couplers 6. Specifically, a total of six annular electrodes are provided corresponding to the terminal portions 24A, 24B, in order from the outer periphery: main electrode (positive) d1, main electrode (negative) d2, control power electrode (positive) d3, control power electrode (negative) d4, communication line electrode (positive) d5, and communication line electrode (negative) d6.

Furthermore, the upper end surface 50a and the lower end surface 50b are provided with similar vertical connecting portions 56 that connect to the vertical connecting portions 26 of the battery module 2. Various configurations are possible, such as those with engaging or engaged portions, or those in which the terminal portions 53A, 53B and the terminal portions 24B, 24A on the battery module 2 that connect to them are structured as male and female terminals that can be connected to each other. In this example, the connection is made by the connecting structure of the coupler 6.

In addition, a through-hole 57 is provided in the center of the upper end surface 50a and the lower end surface 50b, corresponding to the position (center) of the aforementioned through-hole 27 of the connectable battery module 2 and the position of the through-hole 63 of the connector 61 of the coupler 6, and allowing the transfer of refrigerant between the battery module 2 and the connector 61.

As shown in Figures 15(a) and 15(b), a coupler 8 is attached to a paralleling module 5 for connecting it to other paralleling modules 5 that constitute serial blocks. To enable multiple paralleling modules 5 to be connected to a single paralleling module 5, the coupler 8 is designed to be attached to a triangular region (six regions in this example) formed by dividing the polygonal shape of the upper or lower end face of the paralleling module in plan view by a diagonal line passing through the center. The coupler 8 includes a pair of triangular connectors 81 (as viewed from above) on opposing surfaces (connection surfaces 81a) with arc-shaped connecting terminals 80A that are electrically connected to the arc-shaped terminal portions 53A (53B) of the paralleling modules 5 within the triangular region, and a connecting portion 82 between the connectors 81, incorporating connecting wires 80C that electrically connect the connecting terminals 80A together.

Specifically, the connecting terminal 80A corresponds to the terminal portion 53A and has six concentric arc-shaped electrodes: main electrode (positive) d1, main electrode (negative) d2, control power electrode (positive) d3, control power electrode (negative) d4, communication line electrode (positive) d5, and communication line electrode (negative) d6, in order from the side closest to the connecting portion 82. The electrodes of each connecting body 81 are connected by connecting wires. Each connecting body 81 of the coupler 8 has a connecting structure that engages with a vertical connecting portion provided on the upper end surface 50a. Various configurations are possible, such as those with engaging or engaged portions, or those in which the terminal portions 53A and 80A are connected to each other as male and female terminals.

By connecting parallelization modules 5 using such connectors 8, it is possible to connect parallelization modules 5 in an appropriate direction on multiple sides (six sides at 60-degree intervals in this example). Furthermore, as shown in Figure 15(b), multiple parallelization modules 5 can be connected to one parallelization module 5. In a preferred embodiment, one of the multiple parallelization modules 5 connected using connectors 8 in this way is configured as the master with output terminals (+/-) (output terminal (+) Tpo and output terminal (-) Tmo in Figure 20), and the other parallelization modules 5 are configured as slaves. Such output terminals can be provided in appropriate locations on the housing 50 of the master parallelization module 5. Two or more, or all, of the parallelization modules 5 may also be masters. Furthermore, because the terminals 53A/53B are partially exposed on the top and bottom end faces of the parallelization module 5 except in the areas where the connectors 6/8 are provided, it is preferable to provide protective caps to cover the exposed areas or the entire end faces.

When multiple battery modules 2 are connected via couplers 6, the main electrode (positive) d1, main electrode (negative) d2, control power electrode (positive) d3, control power electrode (negative) d4, communication line electrode (positive) d5, and communication line electrode (negative) d6 of one of the adjacent battery modules 2 are connected via the couplers 6 to the main electrode (positive) d1, main electrode (negative) d2, control power electrode (positive) d3, control power electrode (negative) d4, communication line electrode (positive) d5, and communication line electrode (negative) d6 of the other battery module.

Furthermore, when the battery module 2 and the end module 4 are connected via the coupler 6, the main electrode (positive) d1, main electrode (negative) d2, control power electrode (positive) d3, control power electrode (negative) d4, communication line electrode (positive) d5, and communication line electrode (negative) d6 on one side are similarly connected via the coupler 6 to the main electrode (positive) d1, main electrode (negative) d2, control power electrode (positive) d3, control power electrode (negative) d4, communication line electrode (positive) d5, and communication line electrode (negative) d6 on the other side.

Furthermore, when the battery module 2 and the paralleling module 5 are connected via the coupler 6, the main electrode (positive) d1, main electrode (negative) d2, control power electrode (positive) d3, control power electrode (negative) d4, communication line electrode (positive) d5, and communication line electrode (negative) d6 on one side are similarly connected via the coupler 6 to the main electrode (positive) d1, main electrode (negative) d2, control power electrode (positive) d3, control power electrode (negative) d4, communication line electrode (positive) d5, and communication line electrode (negative) d6 on the other side. When multiple series blocks 11, in which the battery modules 2, end modules 4, and paralleling modules 5 are connected via the couplers 6 in this way, the main electrodes (positive) d1 and main electrode (negative) d2 on one side are connected to the main electrodes (positive) d1 and main electrode (negative) d2 on the other side between adjacent paralleling modules 5, respectively.

Figure 17 is a block diagram showing an example of the electrical configuration of a series block 11. The coupler 6 is omitted, and only two battery modules 2 are shown. The housing of each battery module 2 contains a positive path 21 for passing current between the main electrode (positive) d1 on the upper end surface and the main electrode (positive) d1 on the lower end surface, a negative path 22 for passing current between the main electrode (negative) d2 on the upper end surface and the main electrode (negative) d2 on the lower end surface, and an intra-module control unit 23. The positive path 21 and the negative path 22 each contain multiple unit modules EM (power storage units (battery cells) B1). Each unit module EM has a terminal T1 (first terminal) and a terminal T2 (second terminal). For reference, "(top)" in the diagram indicates the electrode on the upper end surface, and "(bottom)" indicates the electrode on the lower end surface.

The multiple unit modules EM in the positive side path section 21 are connected in series, and between adjacent unit modules EM, the terminal T2 of the unit module EM on the higher potential side is connected to the terminal T1 of the unit module EM on the lower potential side. The terminal T1 of the unit module EM on the highest potential side is connected to one main electrode (positive) d1, and the terminal T2 of the unit module EM on the lowest potential side is connected to the other main electrode (positive) d1. As a result, the positive side path section 21 forms a current path from one main electrode (positive) d1 to the other main electrode (positive) d1.

The negative side path section 22 is configured similarly to the positive side path section 21, except that the terminal T1 of the unit module EM on the highest potential side is connected to one main electrode (negative) d2, and the terminal T2 of the unit module EM on the lowest potential side is connected to the other main electrode (negative) d2. As a result, the negative side path section 22 forms a current path from one main electrode (negative) d2 to the other main electrode (negative) d2. Note that the number of unit modules EM in the positive side path section 21, i.e., the number of power storage units B1, may be one, and the number of unit modules EM in the negative side path section 22, i.e., the number of power storage units B1, may be one.

Figure 18 is a schematic circuit diagram illustrating the configuration of a unit module EM. The unit module EM includes terminals T1 and T2, a power storage unit B1 that stores electric charge, and switching elements SW1 and SW2 (switching circuits) that switch the electrical connection state of the power storage unit B1 to terminals T1 and T2. The switching elements SW1 and SW2 are an example of a switching circuit, and in the example shown in Figure 18, they form a half bridge.

Specifically, the power storage unit B1 and switching element SW1 are connected in series, and switching element SW2 is connected in parallel to the series circuit of power storage unit B1 and switching element SW1. The connection point between switching element SW1 and switching element SW2 is connected to terminal T1, and the connection point between switching element SW2 and power storage unit B1 is connected to terminal T2.

Terminal T1 is connected to terminal T2 of the unit module EM that is at a higher potential than its own module, and terminal T2 is connected to terminal T1 of the unit module EM that is at a lower potential than its own module. This connects multiple unit modules EM in series. Various switching elements can be used as switching elements SW1 and SW2, and semiconductor switching elements such as transistors are suitable. Switching elements SW1 and SW2 are turned on and off in response to control signals from the module control unit 23.

The power storage unit B1 of the unit module EM indicated by the symbol A is in an on-connection state, while the power storage unit B1 of the unit module EM indicated by the symbol B is in a disconnection state. In the on-connection state, switching element SW1 is on and switching element SW2 is off, causing power storage unit B1 to be connected to the current paths of positive path portion 21 and negative path portion 22. In the disconnection state, switching element SW1 is off and switching element SW2 is on, causing power storage unit B1 to be disconnected from the current paths of positive path portion 21 and negative path portion 22.

The unit module EM may use a full bridge as the switching circuit. Figure 19 is a conceptual circuit diagram showing an example of a unit module EM using a full bridge as the switching circuit. The full-bridge unit module EM shown in Figure 19 further includes switching elements SW3 and SW4 in addition to the half-bridge unit module EM shown in Figure 18. Switching elements SW3 and SW4 can be the same as switching elements SW1 and SW2.

Specifically, the series circuit of switching elements SW3 and SW4 is connected in parallel to the series circuit of switching elements SW1 and SW2. The connection point of switching elements SW1 and SW2 is connected to terminal T1, and the connection point of switching elements SW3 and SW4 is connected to terminal T2. The full-bridge unit module EM shown in Figure 19 can be in the connected state indicated by symbol A, the disconnected state indicated by symbol B, and the inverted state indicated by symbol C. In the inverted unit module EM, the power storage unit B1 is connected with the polarity reversed.

In the join state, switching elements SW1 and SW4 are on, and switching elements SW2 and SW3 are off. In the detach state, switching elements SW1 and SW3 are off, and switching elements SW2 and SW4 are on. In the inverted state, switching elements SW1 and SW4 are off, and switching elements SW2 and SW3 are on. Note that in the detach state, switching elements SW1 and SW3 may be on, and switching elements SW2 and SW4 may be off.

The module control unit 23 shown in Figure 17 is configured with, for example, a CPU (Central Processing Unit) that performs predetermined logical operations, RAM (Random Access Memory) that temporarily stores data, a non-volatile storage device, a serial communication circuit, and peripheral circuits for these, and operates by executing a predetermined program.

The intra-module control unit 23 turns the switching elements SW1 and SW2 on and off in accordance with control information obtained from the communication line electrode (positive) d5, switching the connection state of each unit module EM in the battery module 2. Hereinafter, the intra-module control unit 23's control of the switching elements SW1 and SW2 to control the connection state, including the connected state and disconnected state, or the control of the switching elements SW1 to SW4 to control the connection state, including the connected state, disconnected state, and reversed state, will simply be referred to as "controlling the connection state."

As shown in FIG. 17, the end module 4 includes inductors L1 and L2, an end control unit 41, and a current sensor 42 within its housing. One end of inductor L1 is connected to the positive main electrode d1, the other end of inductor L1 is connected to one end of inductor L2, and the other end of inductor L2 is connected to the negative main electrode d2. That is, inductors L1 and L2 are interposed between the positive main electrode d1 and the negative main electrode d2. The connection point between inductors L1 and L2, i.e., the midpoint of inductors L1 and L2, is conductively connected to the intermediate connection terminal Ti. Note that a center-tapped reactor may be used instead of inductors L1 and L2, and the center tap may be connected to the intermediate connection terminal Ti. The intermediate connection terminal Ti is provided at an appropriate location on the outer surface of the housing 40, as shown in FIG. 11.

By providing the end module 4 with inductors L1 and L2, the battery pack system 1 can operate as an inverter circuit. The end module 4 does not necessarily have to include inductors L1 and L2 and the intermediate connection terminal Ti, and the main electrode (positive) d1 and main electrode (negative) d2 may be short-circuited. The current sensor 42 detects the current flowing through the battery string 3 and outputs the current value to the end control unit 41.

The end control unit 41 is configured, for example, with a CPU that performs predetermined logical operations, RAM that temporarily stores data, a non-volatile storage device, a serial communication circuit, and peripheral circuits for these, and operates by executing a predetermined program. The end control unit 41 transmits the current value detected by the current sensor 42 as a second serial signal SS2 (second signal) to the communication line electrode (negative) d6.

The paralleling module 5 includes a control unit 51 and a filter 52 within its housing. The filter 52 is a so-called LC filter that includes an inductor L interposed between the main electrodes (positive) d1 and a capacitor C interposed between the main electrodes (positive) d1 and (negative) d2.

The control unit 51 is configured with, for example, a CPU that performs predetermined logical operations, RAM that temporarily stores data, a non-volatile storage device, a serial communication circuit, and peripheral circuits for these, and operates by executing a predetermined program. The control unit 51 outputs control information for each battery module 2 and end module 4 as a first serial signal SS1 (first signal) that is connected in the connection order of the multiple battery modules 2 and end modules 4 in the series block 11 to the communication line electrode (positive) d5 of an adjacent battery module 2 via the communication line electrode (positive) d5.

Note that while the first serial signal SS1 is shown as an example of the first signal and the second serial signal SS2 is shown as an example of the second signal, the first signal and the second signal may be parallel signals. Furthermore, the communication line electrode (positive) d5 and the communication line electrode (negative) d6 may be configured as connectors in which the conductors come into contact with each other. Alternatively, they may be configured to be connected one-to-one using non-contact means such as radio waves or light.

When multiple battery modules 2, end modules 4, and paralleling modules 5 configured as described above are connected, the power storage units B1 in the connected state in all battery modules 2 are connected in series via inductors L1 and L2, and the sum of the output voltages of the power storage units B1 is output. Since the battery pack system 1 can increase or decrease the number of connected battery modules 2, the output voltage can be changed by increasing or decreasing the number of battery modules 2 according to the voltage required for each electrically powered device, such as an electric vehicle. Therefore, the battery pack system 1 can be applied to a variety of electrically powered devices, making it easy to increase the degree of commonality.

Furthermore, the number of connected power storage units B1 can be dynamically changed using control information, making it possible to fine-tune the output voltage according to the state of charge and output voltage of the power storage units B1. Furthermore, if the end module 4 is configured to include inductors L1, L2 and an intermediate connection terminal Ti, the battery pack system 1 can be operated as an inverter circuit, and two battery pack systems 1 can be used to output a single-phase AC voltage from the intermediate connection terminal Ti, or three battery pack systems 1 can be used to output a three-phase AC voltage from the intermediate connection terminal Ti.

Next, the parallel connection of the series blocks 11 will be described. Figure 20 is an explanatory diagram for explaining the parallel connection of the series blocks 11. Figure 20 omits the illustration of the coupler 6, filter 52, inductors L1 and L2, and intermediate connection terminal Ti.

When multiple series blocks 11 are connected, as shown in FIG. 20 , the main electrodes (positive) d1 and (negative) d2 on one side are connected to the main electrodes (positive) d1 and (negative) d2 on the other side by couplers 8 between the paralleling modules 5. As a result, multiple series blocks 11 are connected in parallel. This increases the current capacity output between the main electrodes (positive) d1 and (negative) d2. In this way, using the paralleling modules 5 makes it easy to increase or decrease the number of series blocks 11 connected in parallel. As a result, the current capacity of the battery pack system 1 can be easily changed. Therefore, the battery pack system 1 can easily be adjusted to have a current capacity that corresponds to the current required for each electrically powered device, such as an electric vehicle.

Furthermore, when multiple series blocks 11 are connected in parallel and the unit modules EM of each series block 11 are switched using MMC control or the like, differences in the instantaneous values of the output voltage between the series blocks 11 occur. This undesirably results in repeated instantaneous current inputs and outputs between the series blocks 11. Therefore, by providing a filter 52 in the paralleling module 5 and smoothing the output voltage of each series block 11, it is possible to reduce the instantaneous current inputs and outputs between the series blocks 11.

It should be noted that it is not necessary to provide the filter 52 and the control unit 51 in the paralleling module 5. A control unit may be provided outside the paralleling module 5, or multiple series blocks 11 may be controlled by a single control unit. The control unit 51 may also be provided in the end control unit 41. Alternatively, the control unit 51 may not be provided, and may be provided outside the battery pack system 1. It is also possible to not provide the paralleling module 5, and to short-circuit the main electrode (positive) d1 and the main electrode (negative) d2 with a polarity bus bar or a negative electrode bus bar. Various other circuit configurations are possible, and are not limited to the examples given in this embodiment.

REFERENCE SIGNS LIST 1 Battery pack system 2 Battery module 3 Battery string 4 End module 5 Paralleling module 6 Coupler 8 Coupler 11 Series block 20 Housing 20a Upper end surface 20b Lower end surface 20c Side surface 21 Positive path section 22 Negative path section 23 In-module control section 24A, 24B Terminal section 25 Connection section 26 Vertical connection section 27 Through hole 40 Housing 40a Upper end surface 40b Lower end surface 41 End control section 42 Current sensor 43A Terminal section 46 Vertical connection section 47, 48 Through hole 49 Filter 490 Fan 50 Housing 50a Upper end surface 50b Lower end surface 51 Control section 52 Filter 53A, 53B Terminal section 56 Vertical connection section 57 Through hole 60A Connecting terminal 60C Connecting wire 61 Connecting body 61a Connecting surface 62 Connecting portion 63 Through hole 64 Flow path 70 Engaging portion 71 Engaged portion 80A Connecting terminal 80C Connecting wire 81 Connecting body 81a Connecting surface 82 Connecting portion B1 Electric storage portion C Capacitor D1 to D4 Control information EM Unit module L Inductor M1 to M4 Module information SS1 First serial signal SS2 Second serial signal SW1 to SW4 Switching elements T1, T2 Terminal Ti Intermediate connecting terminal d1 Main electrode (positive)
d2 Main electrode (negative)
d3 Control power electrode (positive)
d4 Control power supply electrode (negative)
d5 Communication line electrode (positive)
d6 Communication line electrode (negative)

Claims (10)

A battery pack system comprising a plurality of battery modules connected together,
The battery module includes:
a housing accommodates one or more power storage units, and the housing has terminals serving as electrodes on the upper and lower end surfaces thereof, and the plurality of battery modules are electrically connected via the terminals;
A battery pack system characterized in that a connecting portion is provided on a side surface of the housing to connect two of the battery modules with the sides of the housing facing each other. The battery pack system of claim 1, wherein the housing of each battery module has a prism shape with polygonal upper and lower end surfaces. The battery pack system of claim 2, wherein the connecting portion has an engaging portion and an engaged portion, which are structured to engage with each other, on a pair of flat side surfaces of the prismatic housing that are symmetrical about the axis. The battery module of claim 3, wherein the engaging portion and the engaged portion comprise a dovetail-shaped or T-groove-shaped recess extending in the axial direction, and a protrusion shaped to fit into the recess and engage with the groove so as to be movable relative to the groove in the axial direction. a connector that electrically connects the two battery modules connected by the connecting portion;
The coupler comprises:
a pair of connectors connected to each upper end surface or each lower end surface of the battery module and having connecting terminals electrically connected to the terminal portions provided on the surfaces; and a connecting wire provided between the connectors and electrically connecting the connecting terminals to each other,
The battery pack system according to claim 1 . The battery module includes:
a coolant flow port for allowing a coolant to flow into and out of the housing is provided on an upper end surface and a lower end surface of the housing,
the coolant flow ports are provided at positions corresponding to each other so as to communicate with each other when the two battery modules are connected with the upper end surface of one housing and the lower end surface of the other housing facing each other.
Battery pack system. a connector that electrically connects the two battery modules connected by the connecting portion;
The coupler comprises:
a pair of connectors connected to the upper end surfaces or the lower end surfaces of the battery modules and having connecting terminals electrically connected to the terminal portions provided on those surfaces; and a connecting wire provided between the connectors and electrically connecting the connecting terminals to each other; and a refrigerant flow passage communicating with the refrigerant flow ports provided on the upper end surfaces or the lower end surfaces and for transferring a refrigerant from one refrigerant flow port to the other refrigerant flow port.
The battery pack system according to claim 6. The battery module includes:
a first positive terminal and a first negative terminal as the electrodes on the upper end surface;
a second positive terminal and a second negative terminal as the electrodes on the lower end surface;
a positive path portion for allowing a current to flow between the first positive terminal and the second positive terminal;
a negative path portion for allowing a current to flow between the second negative terminal and the first negative terminal;
a switching circuit configured to switch a connection state of a current path in at least one of the positive-side path portion and the negative-side path portion, the connection state including an adding state in which the power storage unit is added to the current path and a removing state in which the power storage unit is removed from the current path;
The battery pack system according to claim 1 . A battery module for use in the battery pack system according to any one of claims 1 to 8,
One or more power storage units are housed inside the housing,
the housing has terminal portions serving as electrodes on the upper and lower end surfaces thereof, and the plurality of battery modules can be electrically connected via the terminal portions;
a connecting portion is provided on a side surface of the housing to connect the two battery modules together with the side surfaces of the housing facing each other;
Battery module. A coupler used in the battery pack system according to any one of claims 1 to 8, electrically connecting two of the battery modules connected by the connecting portion,
a pair of connectors connected to the upper end surfaces or the lower end surfaces of the battery module, the connectors having connecting terminals electrically connected to the terminal portions provided on the surfaces;
and connecting wires provided between the connecting bodies and electrically connecting the connecting terminals to each other.
coupler.