KR20130025329A - Battery pack for large energy storage system and method to charge the same - Google Patents

Abstract

PURPOSE: A large sized battery pack is provided to facilitate the production of a battery pack, to minimize the capacity of a unit cell, and to improve productivity. CONSTITUTION: A battery pack comprises a case with guide grooves; many trays which are inserted into the guide groove; and a battery cell assembly supplied to the trays. The tray consists of a first connecting element(17) for connecting both electrodes of the battery cell assembly, and a second connecting element(19) for connecting the negative electrode of the battery cell assembly. The battery cell assembly consists of a plurality of unit cells(25) which are coupled with the first and second connection unit in parallel.

Description

Battery pack and its charging method {Battery pack for large energy storage system and method to charge the same}

The present invention relates to a large-capacity battery pack and a charging method thereof that can be used in a device for supplying a large amount of power, such as an electric vehicle, an uninterrupted power supply (UPS), a power supply for a smart grid (Smart grid). .

In general, a large capacity rechargeable battery may be used as a driving source of an electric vehicle, and may also be used as an uninterruptible power supply device that supplies stable power by overcoming a power failure that may occur in a commercial power source. And such a rechargeable battery can also be used as a smart grid power supply.

The rechargeable battery has a battery pack form in which several battery cells are integrally connected according to their capacity. Since the battery pack charges with one charger and passively manages cell deviations, the battery pack may shorten the lifespan of the battery packs due to the charge variation of the cells and may be difficult to maintain when operated for a long time.

In particular, the transport regulations for dangerous goods in each country may classify battery cells or battery packs in excess of the prescribed capacity as dangerous goods. Therefore, the conventional battery cell or battery pack has a problem in that the transportation cost is increased because the special packaging must be carried during transportation.

Accordingly, the present invention has been proposed to solve the above problems, an object of the present invention is to manufacture a battery module by connecting a plurality of small capacity unit cells (Cell) in parallel, and assembling the battery module to the case at regular intervals The present invention provides a large capacity battery pack and a charging method thereof, which can be easily manufactured as well as easy to maintain a large capacity battery pack.

Still another object of the present invention is to provide a large capacity battery pack and a charging method thereof capable of minimizing the capacity of a unit cell constituting the battery module to reduce transportation costs and improve productivity.

Still another object of the present invention is to provide a large capacity battery pack and a charging method thereof, which facilitate cell balancing of battery modules formed by small capacity unit cells, thereby preventing performance degradation and shortening of life.

It is still another object of the present invention to provide a large capacity battery pack and its charging method for increasing the commerciality through rapid charging.

It is still another object of the present invention to provide a large capacity battery pack and a charging method thereof that can be easily connected to various devices and thus can be widely used without changing the design.

In order to accomplish the above object, according to the present invention, there is provided a portable information terminal, comprising: a case having a pair of guide grooves facing each other at regular intervals and having a storage space; a plurality of trays sandwiched by the guide grooves; A cell charger for charging the battery cell assembly and provided to the tray in a one-to-one correspondence with the battery cell assemblies, and a controller for controlling the cell charger, And a temperature sensor for sensing a temperature of the battery cell assembly, wherein the tray includes a first connection member for connecting the anode of the battery cell assembly to the tray, Keep a constant distance from the first connecting member A second connection member is disposed and connects a negative electrode of the battery cell assembly, and the battery cell assembly provides a battery pack including a plurality of unit cells coupled in parallel to the first connection member and the second connection member. .

The first auxiliary connecting member is connected to the first connecting member at regular intervals, and the second auxiliary connecting member is connected to the second connecting member at a position corresponding to the first auxiliary connecting member, and the plurality of units The cell is preferably coupled to the fastening member between the first auxiliary connection member and the second auxiliary connection member.

A portion of the first connection member and the second connection member may protrude to the outside of the tray and a terminal connection hole may be provided at the protruding portion.

Preferably, the first auxiliary connection member and the second auxiliary connection member are formed to have a surface area that is closer to the first connection member and the second connection member, respectively.

The unit cell may be provided with a cylindrical or flat body portion, a unit cell connection terminal coupled to the side of the body portion, and each of the unit cell connection terminals may be provided with fastening holes.

The first connection member and the second connection member are preferably connected by the cell charger and the charging connection member, respectively.

Preferably, the tray is provided with an extension part fitted to the guide groove on both sides.

The tray is preferably coupled to another fastening member.

The cell controller may be provided with a communication connector connected to the main controller to exchange data, and a power connector receiving external power to supply power to the cell charger.

It is preferable that a bidirectional DC / DC converter and a bidirectional DC / AC inverter are connected to the first connection member and the second connection member.

The present invention also provides a method for charging a battery pack, comprising: a first charging step of rapidly charging a battery pack through a bidirectional DC / AC inverter and a bidirectional DC / DC converter, and a cell provided in each tray after the first charging step Provided is a charging method of a battery pack including a secondary charging step of charging the unit cell through a charger.

The primary charging step is preferably charged in the range of 90% to 98% of the total capacity of each unit cell.

In the present invention, a small capacity unit cell is connected in parallel to manufacture a battery module, and the battery modules are assembled at regular intervals in a case to easily manufacture a large capacity battery pack, thereby increasing productivity. It can reduce the maintenance cost.

In addition, the present invention has the effect of reducing the cost of transportation, such as to make the capacity of the unit cell constituting the battery module to less than the handling criteria of dangerous goods to be transported like a general cargo.

In addition, the present invention uses the external charging device to perform the first fast charging, and the second charging through the cell charger provided inside the battery module to increase the charging speed to improve the merchandise as well as cell balancing of the battery module It has the effect of preventing the deterioration of performance and shortening of life.

In addition, the present invention is provided with a terminal connection hole in the front end portion of the first connection member and the second connection member can be easily connected to a variety of devices can be widely used without widening the design range.

1 is a perspective view illustrating an example of a battery pack in which a plurality of battery modules are coupled to a case to explain an embodiment of the present invention.
FIG. 2 illustrates a battery module including a battery cell assembly as an example of an embodiment of the present invention.
3 is a detailed view of the main part of FIG.
4 is a diagram illustrating an example of a unit cell constituting a battery cell assembly to explain an embodiment of the present invention.
5 is a diagram illustrating a battery module to explain an embodiment of the present invention.
6 is a diagram illustrating a battery pack and a charge discharge system to explain an embodiment of the present invention.
7 is a diagram illustrating a battery module including a battery cell assembly as another example of the embodiment of the present invention.
8 is a view showing a battery module including a battery cell assembly as another example of an embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

1 shows a perspective view and a battery pack 1 for explaining an embodiment of the present invention. FIG. 2 is a view illustrating one of battery modules 2 constituting the battery pack 1.

In the description of the embodiment of the present invention, a basic unit capable of supplying power is referred to as a battery module 2 (shown in FIGS. 1 and 2), and such a battery module 2 may include a case 3, FIG. It is referred to as a battery pack (1, the battery pack) that is coupled to form a predetermined interval in a state capable of disassembling and assembling in ().

In the embodiment of the present invention, the battery module 2 is shown as an example in FIGS. 2, 7 and 8, respectively, and the battery module 2 is fitted into the case 3 to form the battery pack 1. Can be.

Meanwhile, the battery module 2 includes a tray 5, a battery cell assembly 7, a cell charger 9, a cell controller 11, a heating mat (not shown), and a temperature sensor 15 as one set. It may include.

And the embodiment of the present invention can be easily fixed to the case 3 by the operator using a fastening member (not shown), such as screws, the battery module 2 and the battery module 2 in the case 3 as necessary It is desirable to have a structure that can easily remove them. This description of the embodiments of the present invention will be described in more detail.

The case 3 is provided with a storage space in which the above-described battery modules 2 can be accommodated. And the case 3 is provided with a plurality of guide grooves (3b) on both sides facing each other.

The trays 5 may be fitted at regular intervals in the guide grooves 3b provided at positions facing each other on both sides of the inner surface of the case 3. The guide grooves 3b are arranged in a constant direction at equal intervals. The trays 5 fitted into the guide grooves 3b are arranged in a plurality of stacked forms along a predetermined direction.

The trays 5 are provided with extensions 5a fitted to the guide grooves 3b described above on both side sides. In other words, the extension portions 5a are fitted into the guide grooves 3b provided in the case 3. The trays 5 may be firmly fixed to the case 3 by a fastening member such as a separate screw.

The coupling structure in which the trays 5 are coupled to the case 3 with a fastening member such as a screw is such that when the battery module 2 is defective or the life is short, the fastening member such as a screw is removed and easily separated into the case 3 So that the new battery module 2 can be coupled to the case 3 again.

As such, the trays 3 and the case 3 are coupled to each other by a fastening member 16 such as a screw to facilitate maintenance of the battery pack 1 and to extend the life of the battery pack 1. have.

The trays 5 have a first connecting member 17 for connecting the positive electrode of the battery cell assembly 7, and are disposed at regular intervals from the first connecting member 17, and the negative electrode of the battery cell assembly 7 is provided. A second connecting member 19 for connecting may be provided.

The first connection member 17 and the second connection member 19 may be disposed to maintain a constant distance from each other and may be a conductive plate formed in a band shape.

The first connection member 17 and the second connection member 19 preferably have a portion (front end) protruding out of the tray 5 and provided with terminal connection holes 17a and 19a in the protruding portion.

The terminal connection holes 17a and 19a may be formed in a circular hole, and may be used to connect the battery module 2, and may have various sizes and shapes according to the capacity of the battery pack 1.

The first auxiliary connecting member 21 is connected to the first connecting member 17 at regular intervals, and the second auxiliary connecting member 19 is disposed at a position corresponding to the first auxiliary connecting member 21 to be connected to the second auxiliary connecting member 21. The connection member 23 may be connected. That is, like the first connecting member 17 and the second connecting member 19, the first auxiliary connecting member 21 and the second auxiliary connecting member 23 may be made of a conductive plate made of a conductor and formed in a band shape. have.

The first auxiliary connecting member 21 may be fixed to the first connecting member 17 by a fastening member such as a screw. In addition, the second auxiliary connection member 23 may also be fixedly coupled to the second connection member 19 by a fastening member such as a screw.

On the other hand, the first auxiliary connecting member 21 and the second auxiliary connecting member 23 has a shape in which the surface area becomes wider or wider as the first connecting member 17 and the second connecting member 19 are closer to each other. It is preferable to consist of (shown in FIG. 3). The shape of the first auxiliary connecting member 21 and the second auxiliary connecting member 23 is to smooth the flow of current even if the current capacity of the battery cell assembly 7 increases. In particular, the shape of the first auxiliary connection member 21 and the second auxiliary connection member 23 can make the battery module 2 more compact by reducing the weight while smoothly flowing the current.

The trays 5 are provided with a battery cell assembly 7. The battery cell assembly 7 preferably includes a plurality of unit cells 25 having a small capacity.

As shown in FIG. 4, the unit cell 25 may include a body portion 25a and a unit cell connection terminal 25b. The body portion 25a may be formed in a cylindrical shape.

The unit cell connection terminal 25b may be coupled to the side of the body portion 25a by spot welding or the like. The fastening hole 25c is provided in the unit cell connection terminal 25b.

In the unit cell 25, the anode of the unit cell connection terminal 25b is coupled to the first auxiliary connection member 21 by a fastening member such as a screw, and the cathode of the unit cell connection terminal 25b is the second auxiliary connection member. 23 is coupled to the fastening member such as another screw.

In this case, it is preferable that the unit cell 25 is coupled to the first auxiliary connection member 21 and the second auxiliary connection member 23 in parallel. Such a unit cell 25 is preferably made of one cell of a small capacity that is not treated as dangerous goods in the dangerous goods transport regulations.

Dozens or hundreds of such unit cells 25 may be connected in parallel to form one battery module 2.

On the other hand, the shape of the body portion 25a of the unit cell 25 is not limited to the example made of a cylindrical as in the above-described example, as shown in FIG. It may be made of). As described above, the unit cell 27 of another exemplary embodiment of the present invention may be formed in various shapes and forms according to design conditions.

The cell charger 9 described above is disposed in the tray 5 in a one-to-one correspondence with the battery cell assembly 7. The cell charger 9 is connected to the first connecting member 17 and the second connecting member 19 by charging connecting members 29 and 31. The cell charger 9 may charge the battery cell assembly 7.

The cell charger 9 may be provided with a printed circuit board in the tray 5 and coupled to the printed circuit board. The charging connection members 29 and 31 may be connected to the cell charger 9 through a printed circuit board.

In addition, the cell controller 11 may be installed on the printed circuit board. The cell controller 11 may control the cell charger 9 related to charging. The cell controller 11 may be disposed on the tray 5 in a one-to-one correspondence with the cell charger 9. In addition, the cell controller 11 may be connected to the communication connector 33 and the power connector 35.

That is, the communication connector 33 and the power connector 35 are installed on the printed circuit board, and they may be connected to the cell controller 11 by a wire or the like.

The cell controller 11 may exchange data with a BMS (not shown) or a main controller (not shown) disposed outside the battery module 2 through the communication connector 33. The power connector 35 may be connected to an external power supply device to supply power to the cell charger 9.

Meanwhile, a bidirectional DC / DC converter 37 and a bidirectional DC / AC inverter 39 installed outside the battery module 2 may be connected to the first connection member 17 and the second connection member 19 ( 6).

On the other hand, the temperature sensor 15 is provided to the tray 5 in a number or a number corresponding to the battery cell assembly 7 to detect the temperature of the battery cell assembly 7 and through the cell controller 11 through the battery management system It can transmit to the main controller (not shown) provided in the (Battery management system).

FIG. 6 is a diagram for describing an exemplary embodiment of the present invention, and is a block diagram illustrating a main part of a battery pack 1 to which a plurality of battery modules 2 are connected. Referring to FIG. 6, the battery modules 2 of the present invention are electrically connected to each other and connected to a bidirectional DC / DC converter 37 and a bidirectional DC / AC inverter 39.

The main controller includes current detectors 41 and 43 for detecting current from the battery pack 1, a first switch 45 for disconnecting power from the battery pack 1, and a second switch for shutting off the battery module power. 46 may be electrically connected (see FIG. 6).

The first switch 45 and the second switch 46 are connected in parallel with a large power control relay, a magnetic contact switch, an insulated gate bipolar transistor (IGBT), or a plurality of power FETs. It is preferable to use an element suitable for power control.

The main controller may receive information on the state of charge of the battery cell assemblies 7 from the cell controllers 11 and control the respective cell chargers 9. In addition, the main controller may control a heating mat (not shown) or a cooling fan (not shown) that adjusts the temperature of the battery cell assembly 7 by receiving a signal having a value measured by the temperature sensors 15. The main controller may control the first switch 45 according to the input signals of the current detectors 41 and 43 described above. The main controller may check the capacity of the battery cell assemblies 7 according to the signals transmitted from the cell controllers 11 and perform cell grading to determine inappropriate battery cell assemblies 7. The main controller may transmit data related to the battery cell assemblies 7 sent from the cell controller 11 and data processed therein to an external memory or communicate with an external computer.

The assembly process of the battery cell assembly 7, the battery module 2, and the battery pack and the charging process of the battery cell assembly 7 according to the embodiment of the present invention made as described above are as follows.

First, the operator arranges the unit cell connection terminals 25b provided on both sides of the unit cell 25 in parallel with the first auxiliary connecting member 21 and the second auxiliary connecting member 23 and uses fastening members such as screws. The unit cell connection terminal 25b is fixedly coupled to the first auxiliary connecting member 21 and the second auxiliary connecting member 23. The unit cell 25 preferably has a capacity that is not classified as dangerous goods during transport, and dozens to hundreds may be installed in one tray 5. These unit cells 25 are preferably connected in parallel.

The operator inserts the battery modules 2 including the battery cell assembly 7 into the guide grooves 3b provided in the case 3, and uses the fastening members such as screws to attach the battery modules 2 to the case 3. 2) combine them.

That is, the operator fits the extension portions 5a provided at both ends of the tray 5 constituting the battery module 2 into the guide grooves 3b. And the worker couples the trays 5 to the case 3 with fastening members such as screws. As such, the battery pack 1 may be manufactured in an assembly form by inserting the battery module 2 into the case 3 to be fixed by the fastening members.

The battery pack 1 may be manufactured by appropriately adjusting the capacity of the battery pack 1 as necessary by connecting the number of battery modules 2 differently according to the required power supply capacity.

And explaining the rapid charging process of the embodiment of the present invention are as follows.

The fast charging is primarily performed by connecting the bidirectional DC / AC inverter 39, the bidirectional DC / DC converter 37, and the first switch 45 to the battery pack 1. At this time, the current may be supplied through the bidirectional DC / AC inverter 39 and the bidirectional DC / DC converter 37 to rapidly charge the battery pack 1.

This primary charging step is preferably charged in the range of 90% to 98% of the total capacity of each unit cell 25. Since the state of charge of each unit cell 25 may be different, it is more preferable to charge about 95% of the total capacity of each unit cell 25.

After the rapid charging is performed as described above, the unit cells 25 are respectively charged by the cell chargers 9 provided in the respective trays 5.

The current supplied to the cell charger 9 is supplied through the second switch 46. The BMS (BMS) determines the state of charge of the battery pack 1 with the information obtained through the current sensor 43 and controls the first switch 45 and the second switch 46 to rapidly charge or the cell charger 9. Perform secondary charging using). For example, when the first rapid charging, the first switch 45 is connected, the second switch 46 is cut off, and when the secondary charging is performed, the second switch 46 is connected and the first switch 45 is connected. Block it.

Then, rapid charging is performed in the first charging step, and cell balancing is simultaneously performed while the individual charging of each unit cell 25 is performed in the second charging step. Therefore, since the charging method of the embodiment of the present invention does not require a separate cell balancing process, the charging time can be further reduced, and at the same time, each unit cell 25 can be charged close to full charge.

Therefore, the embodiment of the present invention can prevent the performance degradation of the battery pack 1 and increase the life. In addition, the present invention can not only replace the battery module 2 individually, but also easily replace the unit cells 25 constituting the battery cell assembly 7 individually, so that maintenance work of the entire battery pack 1 is possible. This makes it easy to increase the life of the overall battery pack.

The rapid charging method of the embodiment of the present invention has an advantage of further increasing the commerciality of the battery pack 1. In particular, the present invention can minimize the capacity of the unit cell 25 can satisfy the laws and regulations on the transfer of dangerous goods and can be transported like a general cargo transport has the effect of reducing the transportation cost.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, And it goes without saying that the invention belongs to the scope of the invention.

1. battery pack; 2. battery module;
3. case, 3b. Guide groove, 5. tray, 5a. Extension,
7. battery cell assembly, 9. cell charger,
11.cell controller, 15.temperature sensor,
17. First connecting member, 17a. Terminal connection hole,
19. Second connecting member, 19a. Terminal connection hole,
21. the first auxiliary connecting member, 23. the second auxiliary connecting member,
25, 27. Unit cell, 25a. Body portion, 25b. Unit cell connection terminal, 25c. Fastener,
29, 31. charging connection member, 33. communication connector,
35. Power connector, 37. Bidirectional DC / DC converter
39. Bidirectional DC / AC inverters, 41,43. Current sensor,
45. first switch, 46. second switch,

Claims (12)

A pair of guide grooves provided to face each other at regular intervals and having a storage space;
A plurality of trays fitted into the guide grooves;
A battery cell assembly provided in each of the trays,
A cell charger that charges the battery cell assembly and is provided in the tray in a one-to-one correspondence with the battery cell assembly,
A cell controller provided in the tray in a one-to-one correspondence with the cell charger and controlling the cell charger;
A temperature sensor provided to the tray in a one-to-one correspondence with the battery cell assembly to sense a temperature of the battery cell assembly,
In the tray
A first connection member connecting the positive electrode of the battery cell assembly;
A second connecting member is disposed at a constant distance from the first connecting member and connects a negative electrode of the battery cell assembly.
The battery cell assembly is
A battery pack comprising a plurality of unit cells coupled in parallel to the first connection member and the second connection member. The method according to claim 1,
The first connection member
The first auxiliary connection member is connected at regular intervals,
The second connection member
A second auxiliary connection member is disposed at a position corresponding to the first auxiliary connection member,
The plurality of unit cells
The battery pack coupled to the fastening member between the first auxiliary connection member and the second auxiliary connection member. The method according to claim 1,
The first connecting member and the second connecting member
A battery pack, a portion of which protrudes out of the tray and is provided with a terminal connection hole in the protruding portion. The method according to claim 1,
The first auxiliary connecting member and the second auxiliary connecting member
A battery pack having a wider surface area as the first connection member and the second connection member are closer to each other. The method according to claim 1,
The unit cell is
A cylindrical or flat body part,
A unit cell connection terminal is provided that is coupled to the side of the body portion,
Battery packs provided with fastening holes in the unit cell connection terminal. The method according to claim 1,
The first connecting member and the second connecting member
Battery packs are respectively connected by the cell charger and the charging connection member. The method according to claim 1,
In the tray
A battery pack provided with an extension portion fitted to the guide groove on both side sides. The method according to claim 1,
In the case
The battery pack is coupled to the tray another fastening member. The method according to claim 1,
The cell controller
Communication connector connected to the main controller to send and receive data, and
The battery pack is provided with a power connector for receiving external power to supply power to the cell charger. The method according to claim 1,
The first connecting member and the second connecting member
Battery pack to which a bidirectional DC / DC converter and a bidirectional DC / AC inverter are connected. In the method of charging the battery pack according to claim 1,
Primary charging phase for fast charging of battery packs through bidirectional DC / AC inverters and bidirectional DC / DC converters, and
Second charging step of charging the unit cell through the cell charger provided in each tray after the first charging step
Charging method of a battery pack comprising a. The method of claim 11,
The primary charging step
Charging method of a battery pack, characterized in that the charge in the range of 90% to 98% of the total capacity of each unit cell.

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