KR20090052520A - Medium and large battery packs with improved safety - Google Patents

Abstract

The present invention provides a high output large capacity secondary battery power unit in which a plurality of battery cells or battery modules are connected in series, a BMS for detecting and controlling the operating state of the secondary battery power unit, and a power switching unit for opening and closing the connection between the secondary battery power unit and an external input / output circuit. And a passive protection device for disconnecting the connection between the power switch and the external input / output circuit, wherein the power switch is disconnected from the secondary battery power supply and the external input / output circuit when the connection with the BMS is interrupted. The passive protection device is configured to ensure the safety of the battery pack by disconnecting the connection between the BMS and the power switch under abnormal operating conditions of the secondary battery power supply unit, corresponding to the operation state of the secondary battery power supply unit independently of the BMS. It provides a configured medium-large battery pack.

Description

Middle or Large-sized Battery Pack of Improved Safety}

The present invention relates to a medium-large battery pack with improved safety, and more particularly, a BMS for detecting and controlling an operating state of a high output large capacity secondary battery power supply unit and a secondary battery power supply unit in which a plurality of battery cells or battery modules are connected in series. And a power protection unit for opening and closing the connection between the secondary battery power supply unit and the external input / output circuit, and a passive protection device for disconnecting the power supply connection unit from the external input / output circuit. Is configured to cut off the connection between the secondary battery power supply unit and the external input / output circuit, and the passive protection element independently of the BMS corresponds to the operation state of the secondary battery power supply unit, and the BMS and the power supply under abnormal operating conditions of the secondary battery power supply unit. By disconnecting the opening and closing part to ensure the safety of the battery pack It relates to a medium-large battery pack made.

As the development and demand for mobile devices increases, the demand for this secondary battery as an energy source is increasing rapidly. Among such secondary batteries, a lot of researches have been conducted and commercialized on lithium secondary batteries with high energy density and discharge voltage. It is widely used.

Rechargeable batteries are not only used for mobile and wireless electronic devices such as mobile phones, digital cameras, PDAs, laptops, but also as energy sources for power devices such as electric bicycles (EVs), electric vehicles (EVs), and hybrid electric vehicles (HEVs). It is attracting a lot of attention.

Small battery packs are packed with one battery cell for small devices such as mobile phones and cameras, while two or more battery cells (hereinafter sometimes referred to as "multi-cell") are used for medium and large devices such as notebooks and electric vehicles. Medium or large battery packs in which battery packs connected in parallel and / or in series are packed are used.

As described above, the lithium secondary battery has a problem of low safety while having excellent electrical characteristics. For example, lithium secondary batteries cause decomposition reactions of battery components, such as active materials and electrolytes, under abnormal operating conditions such as overcharge, overdischarge, exposure to high temperatures, and electrical short circuits to generate heat and gas, resulting in high temperature and high pressure. The condition of may further accelerate the decomposition reaction, resulting in an air ignition or explosion.

Therefore, the lithium secondary battery includes a protection circuit that blocks current during overcharge, over discharge, and overcurrent, a PTC element (Positive Temperature Coefficient Element) that blocks current by increasing resistance when temperature rises, and a current when pressure rises due to gas generation. Safety systems are provided, such as safety vents to shut off or vent the gases. For example, in a cylindrical small secondary battery, a PTC element and a safety vent are usually installed on an electrode assembly (power generation element) of a cathode / separator / cathode embedded in a cylindrical can, and in a rectangular or pouch type small secondary battery, Protection circuit modules and PTC elements are generally mounted on top of a rectangular can or pouch case in which the generator is sealed.

The safety problem of the lithium secondary battery is more serious in the medium-large battery pack of the multi-cell structure. In the battery pack of the multi-cell structure, due to the use of a large number of battery cells, a malfunction in some battery cells may cause a chain reaction to other battery cells, and the resulting ignition and explosion may cause large accidents. . Accordingly, the medium and large battery packs are provided with safety systems such as fuses, bimetals, and battery management systems (BMSs) for protecting the battery cells from overdischarge, overcharge, overcurrent, and the like.

However, the lithium secondary battery is gradually deteriorated in the continuous use, that is, the continuous charging and discharging process, the generator, the electrical connection member, etc. For example, the deterioration of the generator is generated by the decomposition of the electrode material, electrolyte, etc. This causes the battery cells (cans, pouch cases) to gradually expand. Under normal conditions, the safety system BMS detects overdischarge, overcharge, overcurrent, and the like to control / protect the battery pack. However, the risk increases because the battery pack cannot be controlled normally when the BMS is inoperative or malfunctions. Since medium and large battery packs generally have a structure in which a plurality of battery cells are fixedly mounted in a predetermined case, each of the expanded battery cells is further pressurized in a limited case, and may cause fire and explosion under abnormal operating conditions. The risk is greatly increased.

In this regard, Figure 1 is a circuit schematic of a conventional medium-large battery pack. Referring to FIG. 1, a conventional medium-large battery pack 900 detects and controls information about an operation state of a battery module assembly 300 and a battery module assembly 300 including a plurality of battery cells, and controls the BMS 600. ), And a power switch (relay: 700) for opening and closing the connection between the battery module assembly 300 and an external input / output circuit (inverter, etc.) 800 by an operation command of the BMS 600.

The BMS 600 maintains the power switch 700 in an on state under normal operating conditions of the battery module assembly 300, and when the abnormality is detected, the BMS 600 switches to an off state when the battery module assembly 300 is detected. Stops charging and discharging. On the other hand, when a malfunction or non-operation of the BMS 600, since no control is made from the BMS 600, the power switch 700 is continuously kept on (on), the battery module assembly even in abnormal operation state Charge and discharge is continuously performed at 300.

Therefore, there is a very high need for a technology capable of fundamentally securing the safety of medium and large battery packs while solving the above problems.

The present invention aims to solve the problems of the prior art as described above and the technical problems that have been requested from the past.

After extensive research and various experiments, the inventors of the present application independently of the BMS in abnormal operation conditions of the battery module, such as overcharge, overdischarge, overcurrent, if a charge / discharge control system such as BMS causes a malfunction in the battery pack. It was confirmed that the current circuit is blocked by the passive protection device installed in the working structure, thereby ensuring the safety of the battery pack to a desired level.

Accordingly, it is an object of the present invention to provide a medium-large battery pack having a specific structure capable of improving safety.

Medium to large battery packs according to the present invention for achieving the above object, a high output large capacity secondary battery power supply is connected to a plurality of battery cells or battery modules in series;

A battery management system (BMS) for detecting and controlling an operation state of the secondary battery power supply unit;

A power switch unit positioned between the secondary battery power supply unit and an external input / output circuit, and opening / closing a connection between the secondary battery power supply unit and the external input / output circuit by an operation command of the BMS; And

A passive protection device positioned between the BMS and the power switching unit and disconnecting the connection between the power switching unit and the external input / output circuit under abnormal operating conditions of the secondary battery power supply unit;

It contains,

The power switching unit is configured to cut off the connection between the secondary battery power supply unit and the external input and output circuit, when the connection with the BMS is disconnected,

The passive protection element independently of the BMS corresponds to the operation state of the secondary battery power supply unit, and is configured to ensure the safety of the battery pack by disconnecting the connection between the BMS and the power switch under abnormal operating conditions of the secondary battery power supply unit.

As described above, in a medium-large battery pack including a secondary battery power supply unit in which a plurality of battery cells or battery modules are connected, the BMS senses an operation state of the secondary battery power supply unit and controls its charging and discharging to secure safety. If the bar is made of a non-operation or malfunction BMS there was a problem that can not control the charge and discharge of the secondary battery power supply.

On the contrary, in the medium-large battery pack according to the present invention, since a passive protection device operating independently of the BMS is located between the BMS and the power switch, the secondary battery power supply is abnormally operated, and the BMS is inoperative or malfunctions. The protection device operates by itself (independently) to disconnect the BMS from the power switch, and accordingly, the power switch disconnects the secondary battery power supply from the external input / output circuit, thereby transferring the overcurrent or overvoltage of the secondary battery power supply to the external input / output circuit. Can be prevented, and the safety and reliability of the battery pack can be ensured.

Specifically, the medium-large battery pack is equipped with a sensor connected to the BMS, each sensor when the temperature or pressure of the secondary battery power supply unit rises above the set value, or the current or voltage of the secondary battery power supply unit rises above the set value, Detects this situation and delivers it to the BMS, and the BMS is configured to turn off the power switch.

However, when the power switch unit does not operate due to a malfunction of the BMS or the sensor under abnormal conditions in the secondary battery power supply unit, as described above, the abnormal state of the secondary battery power supply unit may be transmitted to the external input / output circuit without filtering. . Therefore, in the present invention, the passive protection device is configured to operate independently of the BMS.

As one example of such operating conditions, the passive protection element may be configured to operate when the temperature or pressure of the secondary battery power supply unit rises above a set value. Specifically, the passive protection device may be a device capable of adjusting the operating temperature to cut off the current at a desired temperature condition, or may be made of a device that operates according to the pressure change by using a phenomenon in which the pressure inside the battery cell increases during overcharging. .

As another example, the passive protection element may be configured as an element that operates in accordance with the change of the current or voltage of the secondary battery power source, the operating conditions in this structure is when the current or voltage of the secondary battery power source rises above the set value. It can be configured to work.

The passive protection device has a structure in which a power failure occurs in response to changes in temperature, pressure, current, voltage, etc. of the secondary battery power supply unit, when each measured value rises above a set value, and there is no particular limitation, for example, high temperature or It may comprise a bimetal structure that operates at overcurrent. That is, by using a bimetal structure that operates in response to temperature or current, when a high temperature or overcurrent of a predetermined value or more occurs in the secondary battery power supply unit, the interconnection may be turned off to achieve a power failure.

For reference, bimetal means a plate-shaped member in which two kinds of thin metal plates having very different thermal expansion coefficients are piled up and down.

Unlike the configuration of the present invention, a passive protection device may be installed on a circuit such as a secondary battery power supply unit, an external input / output circuit, a power switch unit, and the like, so that the structure of directly opening and closing the power supply itself may be considered. However, the medium and large battery packs vary depending on the purpose of use, but in general, since high voltage is generated in the secondary battery power supply unit for high power, placing a passive protection element on such a circuit causes an increase in internal resistance. In some cases, a spark may be generated during the operation of switching the current, which may cause a safety problem. On the other hand, since the BMS is operated at a low voltage, such as 12 V, which is used for the electric field of a vehicle, for example, the configuration of the present invention does not cause the above problems.

On the other hand, the passive protection device may be mounted on the physical space between the battery cells or battery modules. For example, the battery cells or battery modules constituting the battery pack are mounted in parallel with the battery pack frame while forming a predetermined spaced space therebetween so that the refrigerant can flow. By installing the passive protection device in such a space, the passive protection device can be configured to operate in response to an increase in the volume of the battery pack.

The secondary battery power supply unit is formed by stacking two or more rectangular battery modules in which a plurality of battery cells or unit modules are connected in series to each other in the width direction (vertical direction) and the height direction (lateral direction). The overall hexahedral structure (hexahedral laminate) is formed, and the outer peripheral edges of the hexahedral laminate may be made of a battery module assembly of a structure fixed by the frame member.

That is, in the medium-large battery pack, a plurality of rectangular battery modules are stacked in a longitudinal direction and a lateral direction to form a hexahedral stack, and the hexahedral stack is fixed by a frame member, thereby having a compact and stable structure as a whole, and a large number of members. Mechanical fastening and electrical connection can be achieved without the use of

In the above structure, as an example, the battery module hexahedron stack may have various structures according to the stacking form of the rectangular battery modules as its components, and the two rectangular battery modules are arranged to face each other in the horizontal direction. For example, it is preferable that one or more rectangular battery modules are arranged in the longitudinal direction with respect to each rectangular battery module.

As used herein, the term “facing arrangement” means that two rectangular battery modules are arranged such that their same portions face each other. For example, in the rectangular battery module having a structure in which the input / output terminals are located at one side, the input / output terminals of each of the rectangular battery modules may be arranged to face the one side (a) of the hexahedral stack. Such an opposing arrangement has an advantage of further simplifying the configuration for electrical connection and the like.

As another example, the rectangular battery modules are oriented so that the respective input and output terminals face one surface (a) of the hexahedral stack,

On the insulating substrate to be coupled and mounted to the surface (a) is a power supply opening and closing portion of the structure that is mounted on the elements ("control elements") for controlling voltage and current during charging and discharging and their connection members,

In order to control the operation of the battery modules, the BMS may be mounted on the alignment surface (a) or the opposite surface (d) of the input / output terminals.

Therefore, the control elements and the power supply opening and closing portion are mounted on the surface (terminal orientation surface: a) where the input and output terminals are located, so that the connection with the input and output terminals is easy, and the battery control system for controlling the operation of the battery module is provided. The BMS may be mounted on a surface (terminal alignment surface: a) or an opposing surface (d) of the terminal alignment surface (a) where the input / output terminals are located for easy connection with the control elements or the power switch. Such a structure can further simplify the electrical connection structure and the assembly process thereof, reduce the length of the electrical connection means to prevent an increase in internal resistance, and reduce the risk of disconnection of the connection means by external impacts. .

In such a structure, the types of the control elements may vary, and in one preferred example, a main relay which automatically reversibly shuts down overcurrent and high voltage, and is connected to the main relay in an initial discharge process so as to be connected with a high voltage. Of a free charge relay to reduce the voltage and current supplied to prevent the sudden supply of electricity, a resistance connected to or connected to the auxiliary relay to reduce current and voltage, Located in the path, check the operation status of the battery module and when it needs to repair the battery module (service plug) to cut the electricity manually, the current to detect the current on the positive or negative connection circuit and send to the BMS And current sensors. These control elements are to properly control the voltage and current of electricity generated by the charge and discharge of the battery module.

Since the control elements of the present invention acts to cut off when over current, high voltage is applied to the battery modules or when such electricity is generated, and to perform a disconnection as necessary, such as checking or replacing the battery module, It is preferable that the positive electrode and / or the negative electrode of the battery module pass through the control elements before being connected to the external circuit.

Specifically, the electrode of one of the positive and negative terminals, which are the input / output terminals of the rectangular battery module, constitutes a circuit such that the service plug is connected in the order of the main relay / auxiliary relay-current sensor-external input / output terminal, and the other electrode is the service plug only. The circuit can be configured to be directly connected to an external input / output terminal via a non-via control element and other control elements. An electrode via the plurality of control elements may be an anode or a cathode.

In consideration of mounting efficiency, structural stability, etc., the medium-large battery pack according to the present invention has a limited mounting space and may be preferably used as a driving power source for electric vehicles, hybrid electric vehicles, and the like, which are exposed to frequent vibrations and strong shocks.

Accordingly, the present invention provides an electric vehicle or a hybrid electric vehicle including the medium-large battery pack as a driving power source.

Since electric vehicles, hybrid electric vehicles including medium and large battery packs are known in the art, description thereof is omitted herein.

Hereinafter, the content of the present invention will be described with reference to the drawings, but the scope of the present invention is not limited thereto.

2 is a circuit schematic diagram of a medium-large battery pack according to an embodiment of the present invention.

Referring to FIG. 2, the medium-large battery pack 910 includes a secondary battery power supply unit 300, a BMS 600 that detects and controls an operation state of the secondary battery power supply unit 300, and an external input / output circuit 800 connected to an external device. In order to open and close the connection between the secondary battery power supply unit 300 and the external input / output circuit 800 according to an operation command of the BMS 600, a power switch unit located between the secondary battery power supply unit 300 and the external input / output circuit 800 ( 700 and a passive protection element (bimetal: 500) positioned between the BMS 600 and the power supply opening / closing part 700.

The passive protection device 500 is installed between the spaced apart gaps of the unit modules 150 as shown in FIG. 8, and electrically in the middle of the 12V power line connecting the BMS 600 and the power switch 700. It is connected.

Therefore, when the BMS 600 does not control the overcharge and overdischarge of the secondary battery power supply unit 300 due to a malfunction, and the temperature of the secondary battery power supply unit 300 rises above a set value, the passive protection device 500 It is off (off) to disconnect the connection between the power switch 700 and the BMS 600, at this time, the power switch 700 disconnects the secondary battery power supply unit 300 and the external input and output circuit 800, the secondary battery The overcurrent or overvoltage generated in the power supply unit 300 is prevented from being transmitted to the external input / output circuit 800.

FIG. 3 is a perspective view schematically illustrating a structure in which a hexahedral stack of rectangular battery modules is fixed by frame members in the battery module assembly. 4 is a perspective view schematically illustrating a structure in which the power opening and closing part is mounted on one side of the frame member in a state in which the hexahedral stack is excluded from the battery module assembly of FIG. 3. In addition, FIG. 5 schematically shows a front perspective view of a state in which the power switch is mounted on one side of the hexahedral stack in the battery module assembly of FIG. 3, and FIG. 6 schematically shows the rear perspective view of FIG. 5. have.

Referring to these drawings, the battery module assembly 300, which is a secondary battery power supply unit, includes six rectangular battery modules 201, 202, 203, 204, 205, and 206, and rectangular battery modules 201, 202, 203, and 204. , 205, 206 is composed of a frame member 400 for fixing the outer peripheral edges of the hexahedral stack, and the power supply opening and closing portion 700, and exhibits a rectangular parallelepiped shape as a whole.

The six rectangular battery modules 201, 202, 203, 204, 205, and 206 are stacked in two in the transverse direction and three in the longitudinal direction, and input / output terminals 240 and 242 formed on one side thereof. ) Are stacked in opposing arrangements so that they are adjacent to each other. That is, the upper row battery modules 201, 202, 203 and the lower row battery modules 204, 205, 206 have a symmetrical structure with respect to the virtual center line, so that the upper row battery modules 201, 202 and 203 are stacked on the battery modules 204, 205 and 206 in the lower row in an inverted form.

Each of the rectangular battery modules 201, 202, 203, 204, 205, and 206 has a structure in which a plurality of plate-shaped unit modules are built in a standing shape, and the frame member 400 includes 12 outer circumferences of a hexahedral stack. It consists of a structure in which a plurality of frames are combined to secure the corners stably, and the six sides of the six-sided stack is opened to the outside while the six-sided stack is mounted.

On the front side of the hexahedral stack on which the input / output terminals 240 and 242 are located, a current is charged and discharged as necessary, an appropriate voltage drop is performed during the operation or disassembly of the battery system, and the rectangular battery modules are provided. And a power supply opening / closing part 700 for electrically connecting the circuit and protecting the circuit from overcurrent, overvoltage, and the like. Since the input / output terminals 240 and 242 of the rectangular battery modules 201, 202, 203, 204, 205, and 206 are adjacent to each other, the power supply opening / closing part 700 is easily connected, and the length of the member for electrical connection. Can be greatly reduced. In addition, since the power supply opening and closing unit 700 is mounted in a form of sealing the input / output terminals 240 and 242, it is possible to prevent a short circuit, etc., which may be caused by being exposed to the outside, and structurally weak input / output terminals 240, 242 can be prevented from being deformed by an external force. That is, the power opening / closing part 700 also serves as a kind of protection member for the input / output terminals 240 and 242 of the rectangular battery modules 201, 202, 203, 204, 205, and 206. More details of the power switch 700 will be described below with reference to FIGS. 10 and 11.

FIG. 7 is a perspective view schematically showing one battery module constituting the battery module assembly, and FIG. 8 is a schematic cross-sectional view of a battery module equipped with a passive protection device according to an embodiment of the present invention. .

First, referring to FIG. 7, the battery module 200 has a structure in which the unit modules 150 are mounted on the upper and lower assembled cases 220 and 230 in an upright state to the side, and the upper case 220. The input and output terminal 240 is formed on the front of the. A bus bar 250 for electrical connection with the input / output terminal 240 is formed on the front surface of the lower case 230, and a connector 260 for connection of a sensor for detecting voltage and temperature is mounted on the rear surface of the lower case 230.

Referring to FIG. 8 together with FIG. 7, a plurality of fixing grooves 350 into which an electrode terminal connecting portion 310 and an electrode terminal connecting portion 310 are inserted and mounted between the unit modules 150 are inserted into the battery module case. ) Is formed. The fixing grooves 350 are formed in a shape corresponding to the electrode terminal connecting portion 310 to prevent the flow of the unit modules 150 and to maintain a stable insulation state with the electrode terminal connecting portion 310 adjacent to each other. give. Specifically, the fixing groove 350, the cell cover flow prevention jaw 352, the cell cover fixing guide 354, the electrode terminal to provide a more stable fixing and insulating state of the unit modules 150 An isolation wall 356 and the like are formed.

In addition, a through hole 362 is formed at the center of the battery module case so as to be fixed to an external device (not shown), and a fastening part 360 protruding from the lower case 230 is provided. Formed. The unit modules 150 are mounted on the battery module cases 220 and 230 in a structure spaced apart from each other to secure the flow path of the insulation and the refrigerant, and the passive protection device 500 between the gaps of the unit modules 150. ) Is installed.

9 is a schematic vertical cross-sectional view of a passive protection device installed in the battery module of FIG.

Referring to FIG. 9, the passive protection device 500 having a bimetal structure has a switch in an on state when the temperature of the battery module is normally within a set value, and is switched when the temperature of the battery module rises above the set value. Is changed to the off state.

General structures and principles of bimetals are well known in the art, and thus detailed descriptions thereof will be omitted.

10 and 11 schematically show an enlarged perspective view and a plan view of the power supply opening and closing portion of FIG. 4.

Referring to these drawings, the power supply opening and closing portion 700 has a structure in which various control elements are mounted on an insulating thick plastic substrate 710 and they are connected by a bus bar 724 and a wire 730. .

Based on the case where the introduction position of the wire connected to the input / output terminal of the battery module is the lower direction of the substrate 710, the service plug 714 and the central portion of the substrate 710 are located near the upper direction of the substrate 710 adjacent thereto. The auxiliary relay 720 is located at the other side of the main relay 716, the substrate 710 corresponding to the wire, the resistor 718 is located at the bottom of the auxiliary relay 720, and the current sensor 722 is located at the top thereof. It is composed of compact structure as a whole in a limited space.

 The external input / output terminals 726 and 728 are located together on one side of the service plug 714, and the positive external input / output terminal 726 and the negative external input / output terminal 728 are other electrical devices such as inverters and LDCs (not shown). Not connected) such as cables or wires.

The positive electrode input / output terminal (FIG. 3: 240) of the battery modules constituting the battery module hexahedron of FIG. 3 is connected to the positive electrode terminal 732 connected to the service plug 714, so that the main relay 716 and the auxiliary relay ( 720, a current sensor 722 is connected to the anode external input / output terminal 726. On the other hand, the negative electrode input / output terminal (FIG. 3: 242) of the battery modules is connected to the negative electrode terminal 734 connected to the service plug 714, and then directly connected to the negative electrode external input / output terminal 728 without passing through other control elements. do. Therefore, when one of the control plugs 714, the main relay 716, and the auxiliary relay 720, which are the control elements constituting the power opening and closing unit, is operated in an OFF state, power cut may be performed as a whole.

The service plug 714 serves to disconnect power as necessary to ensure safety of the operator and the system when assembling and inspecting the battery module assembly and replacing the battery module or some control elements.

The main relay 716 serves to secure the safety of the system by blocking when the applied electricity to the battery module or the electricity generated therefrom is an overcurrent or a high voltage above a specified value.

The auxiliary relay 720 and the resistor 718 interlocked with the auxiliary relay 720 are suitable to prevent overloading of the system by momentary energization while energizing is performed while the system is stopped, such as starting a vehicle. It plays a role in enabling the electricity of the voltage and the current which is drastically dropped. Therefore, the auxiliary relay 720 operates when the vehicle starts up, and when the appropriate operating condition is reached, the auxiliary relay 720 no longer operates.

On the other hand, the insulating plastic substrate 710 has a shape that can be installed to match the open right surface consisting of the integrated front frame 450 and the integrated rear frame and the upper right frame 410 and the lower right frame 430 in FIG. It is made of a size, and has a structure in which the coupling fastening portion 712 protrudes on both sides, so that at least two corners are stably coupled to the frame member on one outer peripheral surface of the battery module assembly.

Accordingly, the plastic substrate 710 of the power opening / closing part 700 not only provides a space in which relevant elements, bus bars and wires are mounted, but also serves as a structure for supporting a frame of the frame member.

In addition, in FIG. 10, one end of the main relay 716 is connected to a 12V power line 734 for supplying power for the operation of the main relay 716, and is also in the middle of the 12V power line 734. The passive protection element 500 of 8 is electrically connected.

Therefore, when the temperature inside the battery module rises above a predetermined value, the passive protection element 500 is turned off by the principle of bimetal, which is supplied to the main relay 716 through the 12V power line 734. By disconnecting the electricity, the overcurrent generated in the battery module is prevented from energizing the external input / output circuit independently of the BMS (FIG. 2: 600).

12, the structure of the BMS which is a battery management system is shown typically.

Referring to FIG. 12 together with FIG. 6, the BMS 600 is mounted adjacent to an inverter (not shown), which is an LDC and an external input / output circuit, at a position where the power switching unit 700 is mounted inside the housing case body. The fastening part 604 protrudes to one side at one lower end of the side 600, and is fixed to a predetermined part by inserting and fastening a fastening member such as a bolt into the fastening groove 602 of the fastening part 604.

As described above, the medium-large battery pack according to the present invention has a structure in which the passive protection device is positioned between the BMS and the power switch, and the BMS and the power switch in the abnormal operating conditions of the secondary battery power supply such as overcharge, overdischarge, and overcurrent. By disconnecting the electrical connection between the battery pack can greatly improve the safety.

In addition, since the medium-large battery pack according to the present invention includes a passive protection device capable of disconnecting the connection between the power switch and the external input / output circuit in response to the operation state of the secondary battery power source independently of the BMS, the BMS malfunctions or operates. If not, the safety can be guaranteed and the reliability can be greatly improved. Moreover, since the passive protection device can be mounted in the spaced space inside the battery pack, it is possible to easily manufacture a medium-large battery pack without structural change.

Those skilled in the art to which the present invention pertains will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

1 is a circuit diagram of a conventional medium-large battery pack;

2 is a circuit schematic diagram of a medium-large battery pack according to an embodiment of the present invention;

3 is a perspective view of a structure in which a hexagonal stack of rectangular battery modules is fixed by frame members in the battery module assembly;

4 is a perspective view of a structure in which the power opening and closing portion is mounted on one side of the frame member in a state in which the six-layer laminate is removed from the battery module assembly of FIG. 3;

5 is a front perspective view of a state in which the power opening and closing portion is mounted on one side of the hexahedral stack in the battery module assembly of FIG. 3;

6 is a rear perspective view of FIG. 5;

7 is a perspective view of a battery module constituting the battery module assembly;

8 is a schematic horizontal cross-sectional view of a battery module equipped with a passive protection device according to an embodiment of the present invention;

9 is a vertical cross-sectional schematic diagram showing the structure of a passive protection device according to an embodiment of the present invention;

10 and 11 are an enlarged perspective view and a plan view of the power opening and closing portion of FIG.

12 is a perspective view showing the structure of a BMS.

Claims (11)

A high output large capacity secondary battery power supply in which a plurality of battery cells or battery modules are connected in series; A battery management system (BMS) for detecting and controlling an operation state of the secondary battery power supply unit; A power switch unit positioned between the secondary battery power supply unit and an external input / output circuit, and opening / closing a connection between the secondary battery power supply unit and the external input / output circuit by an operation command of the BMS; And A passive protection device positioned between the BMS and the power switching unit and disconnecting the connection between the power switching unit and the external input / output circuit under abnormal operating conditions of the secondary battery power supply unit; It contains, The power switching unit is configured to cut off the connection between the secondary battery power supply unit and the external input and output circuit, when the connection with the BMS is disconnected, The passive protection device independently of the BMS corresponds to the operating state of the secondary battery power supply, by disconnecting the connection between the power supply and the BMS in the abnormal operating conditions of the secondary battery power supply, it is configured to ensure the safety of the battery pack. Medium and large battery pack. The medium and large battery pack according to claim 1, wherein the passive protection element is configured to operate when the temperature or pressure of the secondary battery power supply unit rises above a set value. The medium and large battery pack according to claim 1, wherein the passive protection element is configured to operate when the current or voltage of the secondary battery power supply unit rises above a set value. The medium and large battery pack according to claim 2 or 3, wherein the passive protection device includes a bimetal structure that operates at high temperature or over current. The medium-large battery pack according to claim 2 or 3, wherein the passive protection device is mounted between battery cells or battery modules. The method of claim 1, The secondary battery power supply unit is formed by stacking two or more rectangular battery modules in which a plurality of battery cells or unit modules are connected in series, two or more in the width direction (vertical direction) and the height direction (lateral direction). A medium-large battery pack, comprising a battery module assembly constituting a hexahedron structure (hexahedral stack) and having outer peripheral edges of the hexahedral stack fixed by a frame member. The battery module hexahedron of claim 6, wherein the battery module hexahedron is arranged in a state in which two rectangular battery modules are arranged to face each other, and one or more rectangular battery modules are disposed in a longitudinal direction with respect to each rectangular battery module. Medium-large battery pack, characterized in that consisting of a structure arranged. The method of claim 6, Input / output terminals of each of the rectangular battery modules are oriented to face one surface (a) of the hexahedral stack, On the insulating substrate to be coupled and mounted to the surface (a) is a power supply opening and closing portion of the structure that is mounted on the elements ("control elements") for controlling voltage and current during charging and discharging and their connection members, The medium-large battery pack, characterized in that the BMS is mounted on the alignment surface (a) or the opposing surface (d) of the input and output terminals for the operation control of the battery modules. The control device of claim 8, wherein the control elements include: a main relay for automatically reversing the overcurrent and the high voltage, and an auxiliary relay that is connected to the main relay in the initial discharge process to drop the voltage and the current. relay, a resistance connected to the auxiliary relay to reduce current and voltage, a service plug to manually turn off electricity as needed, and a current sensor to detect current on the positive or negative contact circuits. Medium-large battery pack comprising a (current sensor). 10. The method of claim 9, wherein one of the positive electrode and the negative electrode of the battery module comprises a connection circuit in the order of the service plug-main relay / auxiliary relay-current sensor-external input and output terminals, the remaining electrodes are service plug-external input / output A medium-large battery pack, comprising the connection circuits in the order of the terminals. An electric vehicle or a hybrid electric vehicle comprising the medium-large battery pack according to claim 1 as a driving power source.

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