KR20160080801A - Over charging prevention apparatus and method using potential difference between a plurality of battery modules - Google Patents

Abstract

According to an embodiment of the present invention, an overcharge prevention apparatus using a potential difference between battery modules includes: a first battery module; a second battery module of which the number of stacked cells are different from that of the first battery module; a subtractor calculating a power difference value according to first power of the first battery module and second power of the second battery module; an electric current application switch comparing the power difference value and a preset reference value, and switched on according to the comparison result; a fuse allowing power to flow from external power, and provided with the power from the first battery module and the second battery module according to the switching on and carpeted under preset certain constant power; and a main switch turned off when the fuse is melt.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overcharge prevention apparatus and method using a potential difference between battery modules,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overcharge prevention technique for a battery, and more particularly, to an apparatus and a method for preventing overcharging by using a potential difference between two types of modules having different stacking numbers when sensing an over- It is about.

A rechargeable battery is typically a battery capable of charging and / or discharging, unlike a non-rechargeable primary battery. The rechargeable battery may be used in a single form depending on the type of external device to be applied, or in a form of a module in which a plurality of battery cells are connected to form a single unit.

A BMS (Battery Management System) is configured to manage these batteries. BMS optimizes battery management for eco-friendly vehicles to increase energy efficiency and extend life.

However, the performance of the battery cell is being upgraded while the battery cell is aiming at high efficiency and high output, but the stability thereof is deteriorating. Particularly, this phenomenon appears well in high capacity cells such as battery cells for environmental vehicles. Accordingly, various techniques for securing overcharge safety performance have been developed.

One of the techniques is to measure the voltage of a specific battery cell inside the battery module to be charged and to shut off the charging current when the voltage exceeds the reference voltage. In addition, the OP-AMP comparator is used to compare the measured voltage with a reference voltage to produce a high or low output.

The problem with this approach is that when sensing a voltage, a particular battery cell is constantly monitored and a constant load is applied to the battery cell. Therefore, there is a problem of causing a voltage deviation between battery cells inside the battery module.

In order to solve such a problem, there is a method of measuring the overall voltage of the module, but there is a problem in that the device becomes large because a relatively high high voltage is sensed and a separate decompression device must be constructed.

1. Korean Patent Publication No. 10-2011-0019970 2. Korean Patent Publication No. 10-2013-0051166

The present invention has been proposed in order to solve the problem according to the above background art, and it is an object of the present invention to provide an overcharge protection device for preventing overcharging by using a potential difference between two modules having different stacking numbers, And a method thereof.

The present invention provides an overcharge prevention device and method for preventing overcharging by using a potential difference between two types of modules having different stacking numbers when sensing the voltage of a battery cell to construct an overcharge prevention circuit.

In the overcharge prevention device,

A first battery module;

A second battery module having a stacked number of battery cells different from that of the first battery module;

A subtractor for calculating a power difference value according to the first power source of the first battery module and the second power source of the second battery module;

An energizing switch for comparing the power source difference value with a preset reference value and switching on according to the comparison result;

A fuse blown under a condition of a predetermined constant power source while being supplied with power from the first battery module and the second battery module according to the switching on; And

And a main switch which is turned off when the fuse is rubbed.

At this time, the energizing switch is normally open, and when the power difference value is greater than a preset reference value, the energizing switch is switched on to energize the first power source and the second power source to the fuse.

In addition, a first Janner diode may be provided between the subtracter and the energizing switch, and the first Janner diode may switch on the energizing switch if the power difference value is greater than a preset reference value.

The external power source may be an auxiliary battery.

The main switch may be a relay element.

In addition, a positive diode may be provided between the energizing switch and the fuse.

In addition, a second Janner diode may be provided between the fuse and the contact of the main switch and the ground.

In addition, a resistor may be provided between the second Janner diode and the ground.

In addition, a positive diode may be provided between the external power supply and the fuse.

The overcharge prevention device may further include: a first sensing unit sensing the first power source; And a second sensing unit sensing the second power source.

On the other hand, another embodiment of the present invention provides a method of controlling a battery module, comprising the steps of: (a) calculating a first power source of a first battery module and a second power source of a second battery module having a different battery cell stack count from the first battery module; (b) a subtracter calculating a power difference value according to the first power source and the second power source; (c) comparing the power difference value with a preset reference value, and switching on the energizing switch according to a comparison result; (d) flowing power from an external power source, supplying power from the first battery module and the second battery module according to the switching-on, and fusing the fuse under conditions of a predetermined constant power source; And (e) turning off the main switch as the fuse is rinsed. The present invention also provides a method of preventing overcharging using a potential difference between battery modules.

In this case, in the step (c), if the energizing switch is normally open and the power difference value is greater than a predetermined reference value, the power is switched on and the first power source and the second power source are energized to the fuse .

In addition, (a) may include sensing the first power source and the second power source using a first sensing unit and a second sensing unit, respectively.

According to the present invention, there is no need to monitor a specific battery cell at all times since the potential difference of two kinds of modules having different stacking numbers is used, so that a voltage deviation between battery cells inside the module is not caused.

Another advantage of the present invention is that it does not sense a relatively high high voltage and thus it can be downsized and there is no need to construct a separate decompression device.

1 is a conceptual perspective view of a dual battery module 110, 120 according to an embodiment of the present invention.
2 is a block diagram of an overcharge protection device 200 for preventing overcharging by using the two battery modules 110 and 120 shown in FIG.
FIG. 3 is a flowchart illustrating a process of detecting and blocking overcharging using the two-type battery modules 110 and 120 shown in FIG.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Like reference numerals are used for similar elements in describing each drawing.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. The term "and / or" includes any combination of a plurality of related listed items or any of a plurality of related listed items.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be construed in an ideal or overly formal sense unless expressly defined in the present application Should not.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus and method for preventing overcharging using a potential difference between battery modules according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual perspective view of a dual battery module 110, 120 according to an embodiment of the present invention. Referring to FIG. 1, a first battery module 110 and a second battery module 120 are configured. The number of stacked battery cells of the first battery module 110 is 2P6S. That is, the battery cells are composed of two parallel cells and six series cells.

On the other hand, the number of stacked battery cells of the second battery module 120 is 2P10S. That is, the battery cells are composed of two parallel cells and ten series cells. Of course, this number of laminations is merely an example, and other numbers of laminations are also possible.

The power difference values according to the charging rates of the first battery module 110 and the second battery module 120 are as follows. In an embodiment of the present invention, the voltage V is exemplified, but it is also possible to express it by a current value.

SOC (%) The first battery module (unit: voltage (V) The second battery module (unit: voltage (V) Difference (V) 0 19.4 33.2 13.8 50 22.0 36.8 14.8 100 25.2 42 16.8 Overcharge [cell voltage 4.6V] 27.6 46 18.4

That is, as the charging rate increases, the voltage difference between the battery modules increases.

The battery cells stacked on the battery modules 110 and 120 may be designed as a cylindrical cell, a prismatic cell, a pouch-shaped cell, or the like. The pouch-shaped cells include a flexible cover composed of a thin film, in which the electrical components of the battery cell are arranged.

In particular, pouch-shaped cells are used in order to realize optimum space utilization in one battery cell. The pouch-shaped cells are also characterized by low weight with high capacity.

The edges of such pouch-like cells include a sealing joint (not shown). In addition, the joint connects two thin films of battery cells, and the thin films contain additional components in the cavities formed thereby.

Generally, pouch-shaped cells contain an electrolytic solution, such as a lithium secondary battery or a nickel-hydrogen battery.

Also, the battery cell can be a high voltage battery for an electric vehicle such as a nickel metal battery, a lithium ion battery, and a lithium polymer battery.

Generally, a high-voltage battery is a battery used as a power source for moving an electric vehicle and refers to a high voltage of 100 V or more. However, it is not limited to this, and a low-voltage battery is also possible. The plurality of battery cells are connected by lead-to-lead welding of the battery cells.

A BMS (Battery Management System) (not shown) is attached to the first battery module 110 and / or the second battery module 120, respectively, or integrally attached thereto to constitute a battery pack.

The BMS (Battery Management System) optimizes battery management for eco-friendly vehicles, thereby enhancing energy efficiency and longevity. It monitors battery voltage, current, and temperature in real time and prevents excessive charging and discharging before increasing battery safety and reliability.

Examples of environmentally friendly vehicles include hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), electric vehicles (EVs), low-speed electric vehicles (NEVs) (FCV: Fuel-Cell Vehicle).

2 is a block diagram of an overcharge protection device 200 for preventing overcharging by using the two battery modules 110 and 120 shown in FIG. Referring to FIG. 2, the overcharge protection device 200 includes: A second battery module 120 having a first battery module 110, a first battery module 110 and a second battery module 120 having different numbers of battery cells stacked thereon, a first power source of the first battery module 110 and a second battery module 120, A subtracter 230 for calculating a power source difference value according to the second power source of the power source 240, and comparing the power source difference value with a previously set reference value. The power source switch 240 and the external power source 270, A fuse 250 which is supplied with power from the first battery module 110 and the second battery module 120 and is fused under a condition of a predetermined power source according to the switching on, And a main switch 260 which is turned off when it is rubbed.

The first battery module 110 and the second battery module 120 are different from each other as described above. The first battery module 110 includes two parallel and six series (2P6S) battery cells, and the second battery module 120 includes two parallel and ten series (2P10S) battery cells .

A first sensing unit 211 and a second sensing unit 221 are configured to sense the power of the first battery module 110 and the second battery module 120. Of course, the first sensing unit 211 and the second sensing unit 221 may not be separately configured, but may be configured in the battery module 110 and the second battery module 120.

The subtracter 230 calculates a power difference value according to the first power source of the first battery module 110 and the second power source of the second battery module 120. In other words, if the first power source of the first battery module 110 is 6B (B is the cell voltage) and the second power source of the second battery module 120 is 10B, the power source difference value is calculated as follows.

Therefore, 10B-6B = 4B. In this case, when 4B = 18.0 to 18.8V, the cell voltage B is 4.5V to 4.7V.

The subtracter 230 operates by receiving a power of about 12 V from the external power source 270.

The energizing switch 240 is switched on when the power difference value satisfies the following condition from the subtracter 230 to supply power from the first battery module 110 and / or the second battery module 120 to the fuse 250 Shed.

That is, when the energizing switch 240 is normally open normally and the power difference value (for example, 4B) is larger than a predetermined reference value (for example, 18.0 to 18.8) And / or the second power source of the second battery module 120 to the fuse 250.

Of course, a first Janner diode 202-1 is provided between the energizing switch 240 and the subtractor 230. [ The first energode diode 202-1 may switch on the energizing switch 240 if the power difference value is greater than a preset reference value.

When the energization switch 240 is turned on, the power of the external power source 270 and the power of the first battery module 110 and / or the second battery module 120 (or the first battery module 110 and the second battery module 120) The power source is connected to the first contact 204-1 from the battery pack constituted by the power source 120 and the power source is supplied to the fuse 250 so that the fuse 250 is cut off.

The main switch 260 functions as an entrance to the power source of the battery modules 110 and 120. The main switch 260 is formed of a PRA (Power Relay Assembly). Of course, in addition to such a relay method, semiconductor switching elements such as a field effect transistor (FET), a metal oxide semiconductor FET (MOSFET), an insulated gate bipolar transistor (IGBT), a power rectifier diode, a thyristor, a gate turn- A thyristor, a TRIAC, a silicon controlled rectifier (SCR), and an integrated circuit (IC) circuit.

Of course, the energizing switch 240 may be a semiconductor switching element such as a field effect transistor (FET), a metal oxide semiconductor FET (MOSFET), an insulated gate bipolar mode transistor (IGBT), a power rectifier diode, Gate turn-off thyristor, TRIAC, Silicon Controlled Rectifier (SCR), IC (Integrated Circuit) circuit, etc. can be used.

When the fuse 250 is cut off, the power supply for driving the main switch 260 from the external power supply 270 is stopped, thereby stopping the operation of the main switch 260. As a result, charging and discharging through the main switch 260 is stopped.

A first positive diode 201-1 is provided between the external power source 270 and the fuse 250 and a second positive diode 201-1 is provided between the power switch 240 and the fuse 250. [ A positive diode 201-2 is provided. Therefore, a reverse voltage such as an abnormal voltage does not affect the external power supply 270, the battery modules 110 and 120, and the like. The external power supply 270 may be a secondary battery.

A second Janner diode 202-2 is provided between the fuse 250 and the second contact 204-2 of the main switch 260 and the ground 290. [ The second Janner diode 202-2 causes a reverse voltage greater than a predetermined value to flow from the main switch 260 to the ground 260. Also, a resistor 203 is provided between the second Janner diode 202-2 and the ground 290 to consume a reverse voltage. In addition, the ground 203 becomes the chassis ground.

Particularly, the fuse 250 is disposed so as to pass the operation power of the main switch 260, and may connect the anode and the ground of the battery modules 110 and 120 to induce a disconnection.

FIG. 3 is a flowchart illustrating a process of detecting and blocking overcharging using the two-type battery modules 110 and 120 shown in FIG. Referring to FIG. 3, a power supply difference occurs when battery cell configurations of the first battery module (110 of FIG. 2) and the second battery module (120 of FIG. 2) are different. Therefore, the first power source of the first battery module (110 of FIG. 2) and the second power source of the second battery module (120 of FIG. 2) are sensed and the power source difference value according to the first power source and the second power source difference (Steps S310, S320, and S330). Further, a subtracter (230 in FIG. 2) calculates a power difference value according to the first power source and the second power source.

Subsequently, the subtracter 230 of FIG. 2 determines whether the power difference value is equal to or greater than a preset reference value (for example, 18.4 +/- 0.4) (step S340).

2) is switched on and supplied with power from the first battery module 110 and / or the second battery module 120, and then, when the power difference value is equal to or greater than the reference value, The fuse 250 is rubbed under a constant power supply condition. As the fuse 250 is rubbed, the main switch 260 of FIG. 2 is turned off (steps S350 and S360).

On the other hand, in step S340, if the power difference value is smaller than the reference value, steps S310 to S340 are repeatedly performed.

110: first battery module 120: second battery module
200: overcharge protection device
201-1: first positive diode 201-2: second positive diode
202-1: first jnerner diode 202-2: second jener diode
211: first sensing unit 221: second sensing unit
230: subtracter 240: energizing switch
250: Fuse 260: Main switch
270: External power source

Claims (13)

A first battery module;
A second battery module having a stacked number of battery cells different from that of the first battery module;
A subtractor for calculating a power difference value according to the first power source of the first battery module and the second power source of the second battery module;
An energizing switch for comparing the power source difference value with a preset reference value and switching on according to the comparison result;
A fuse blown under a condition of a predetermined constant power source while being supplied with power from the first battery module and the second battery module according to the switching on; And
A main switch which is turned off when the fuse is rubbed;
And an overcharge prevention device using the potential difference between the battery modules.
The method according to claim 1,
Wherein the energizing switch is normally open and is switched on when the power difference value is greater than a predetermined reference value to energize the first power source and the second power source to the fuse. 3. The method of claim 2,
Wherein a first Janner diode is provided between the subtractor and the energizing switch and the first Janner diode switches on the energizing switch when the power difference value is greater than a preset reference value. Prevention device.
The method according to claim 1,
Wherein the external power source is an auxiliary battery.
The method according to claim 1,
Wherein the main switch is a relay element.
The method according to claim 1,
And a positive diode is provided between the energizing switch and the fuse. The method according to claim 1,
And a second Jener diode is provided between a ground of the fuse and a ground of the main switch.
8. The method of claim 7,
And a resistor is provided between the second Jonner diode and the ground.
The method according to claim 1,
And a positive diode is provided between the external power supply and the fuse.
The method according to claim 1,
A first sensing unit sensing the first power source; And
And a second sensing unit sensing the second power source.
(a) calculating a first power source of the first battery module and a second power source of the second battery module having a different number of battery cell stacks from the first battery module;
(b) a subtracter calculating a power difference value according to the first power source and the second power source;
(c) comparing the power difference value with a preset reference value, and switching on the energizing switch according to a comparison result;
(d) flowing power from an external power source, supplying power from the first battery module and the second battery module according to the switching-on, and fusing the fuse under conditions of a predetermined constant power source; And
(e) turning off the main switch as the fuse is rubbed;
And the battery module is connected to the battery module.
12. The method of claim 11,
Wherein the step (c) comprises switching on the first power supply and the second power supply to the fuse when the energizing switch is normally open and the power supply difference value is greater than a preset reference value. .
12. The method of claim 11,
The method of claim 1, wherein the step (a) comprises sensing the first power source and the second power source using a first sensing unit and a second sensing unit, respectively.

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