KR101562881B1 - Apparatus for managing battery pack and battery pack and laptop computer including the same - Google Patents

Abstract

Disclosed is a battery pack management apparatus for preventing damage to a battery pack by controlling a charging / discharging current of the battery pack so that an overcurrent does not flow to the battery pack.
A battery pack management apparatus according to the present invention includes a charge switching unit provided on a charging / discharging path of a battery pack and switching a charging current supplied to the battery cell to charge the battery cell provided in the battery pack; A discharge switching unit provided on a charging / discharging path of the battery pack and switching a discharging current supplied from the battery cell; A control unit for controlling switching operations of the charge switching unit and the discharge switching unit; And an inductor disposed on the charge / discharge path of the battery pack.
According to the present invention, overcurrent and overvoltage conditions that may occur in the battery pack can be prevented.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a battery pack management apparatus,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a battery pack management device for managing a battery pack, and more particularly to a battery pack management device for managing a charge / discharge current of a battery pack so that a rush current does not flow on a charge / And a battery pack and a notebook computer including the same.

In recent years, demand for portable electronic products such as notebook computers, video cameras, and portable telephones has been rapidly increased, and development of batteries, robots, and satellites for energy storage has been accelerated. Thus, a high performance rechargeable battery Researches are being actively conducted.

The secondary rechargeable batteries are nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium secondary batteries. Among them, lithium secondary batteries have almost no memory effect compared to nickel- It is very popular because of its low self-discharge rate and high energy density.

Particularly, as carbon energy is gradually depleted and the interest in environment is increasing recently, demand for hybrid cars and electric vehicles is gradually increasing all over the world including USA, Europe, Japan and Korea. Since such hybrid vehicles and electric vehicles use the charge / discharge energy of the battery pack to obtain the vehicle driving power, they are more fuel-efficient than the vehicles using only the engine and can not discharge or reduce pollutants. . Therefore, more attention and research are focused on batteries, which are a key component of hybrid cars and electric vehicles.

On the other hand, the safety issue of the battery is one of the biggest social issues in recent years. The use population of electronic products such as notebooks and mobile phones is rapidly increasing. The battery explosion can not only lead to breakage of portable electronic products but also can lead to fire, so it is urgent to secure the safety of the battery. Particularly, a middle- or large-sized battery used in a hybrid vehicle or an electric vehicle is composed of a plurality of unit battery cells connected in series and in parallel, and securing the safety of the battery is more important in that the voltage and the output are very high. Accordingly, various devices for securing the safety of the battery by shutting off the charge / discharge current when the abnormal state of the battery is detected have been used.

Fig. 1 is a view schematically showing a configuration of a conventional battery pack managing apparatus.

Referring to FIG. 1, a conventional battery pack management apparatus is provided between a battery cell 10 and input / output terminals (Pack +, Pack-) of a battery pack. When the charging / discharging circuit 20 is connected to the input / output terminals (Pack +, Pack-) of the battery pack, the management device is connected to the charging / discharging path of the battery pack, A charging switch 40 and a discharging switch 30 for switching the currents respectively and a control unit 50 for controlling the charging switch 40 and the discharging switch 30. [ At this time, the controller 50 is constituted by an element such as an MCU (Micro Control Unit), and controls the charge / discharge switches 30 and 40 to induce charge when the charge device is connected to the charge / discharge circuit 20, And when the power consumption device such as a load is connected to the charge / discharge circuit 20, the discharge is induced.

In the battery pack management device, a field effect transistor (FET) is often used as a charge / discharge switch. As shown in Fig. 1, the parasitic diodes 32 and 42 are connected to the FET bodies 31 and 41 in parallel. These parasitic diodes 32 and 42 have high resistance characteristics. There is no serious problem when a small amount of current flows through the parasitic diodes 32 and 42. However, when an overcurrent flows through the parasitic diodes 32 and 42, due to the high resistance characteristics of the parasitic diodes 32 and 42, Joule's heat can be generated in the heat exchanger 42. Therefore, the temperature of the parasitic diodes 32 and 42 rises, which may damage the FET main bodies 31 and 41 and the like.

For example, when the discharging FET main body 31 is turned on and the charging FET main body 41 is turned off, that is, at the beginning of discharging, a current flows along the D path indicated by the two-dot chain line, Is turned on and the discharge FET main body 31 is turned off, that is, at the beginning of charge, a current flows along the C path indicated by the one-dot chain line, and current flows to the parasitic diodes 32 and 42 provided in the FET . Generally, the control unit 50 included in the battery pack management apparatus controls the charging / discharging current so that the overcurrent does not flow to the parasitic diodes 32 and 42, but the rush current generated at the beginning of charging or discharging There is a problem that the instantaneous overcurrent condition caused by the current can not be controlled properly.

2 is a graph showing a change in magnitude of a current at the initial stage of discharging or charging in a conventional battery pack. Referring to FIG. 2, when a discharging circuit or a charging circuit is connected to the battery pack at time t ₀ , an overcurrent referred to as a rush current may instantaneously flow through the battery pack at the beginning of connection. That is, the charging current of the parasitic diodes 32 and 42 is lower than the permissible current (i ₁ ) of the charging / discharging path of the battery pack until the predetermined time t ₁ elapses from the instant t ₀ at which the charging / discharging circuit 20 is connected A large amount of current can flow.

Although the conventional battery pack management apparatus detects the overcurrent, the control unit 50 can block the overcurrent by using the cutoff device 60 such as a fuse. However, since the overcurrent flows from the moment the overcurrent flows, It takes some time to detect and block this.

Therefore, during the time from the moment the overcurrent flows until it is cut off, the overcurrent flows to the parasitic diodes 32 and 42 of the FET, which may damage the FET including the parasitic diodes 32 and 42.

Charging / discharging control device for solar battery (Korean Patent Publication No. 10-1035705, published on May 19, 2011)

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a battery pack and a battery pack, And an object of the present invention is to provide an improved battery pack management apparatus, a battery pack using the same, and a notebook computer.

Other objects and advantages of the present invention will become apparent from the following description, and it will be understood by those skilled in the art that the present invention is not limited thereto. It is also to be understood that the objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations thereof.

According to an aspect of the present invention, there is provided a battery pack management apparatus, which is provided on a charge / discharge path of a battery pack, and switches a charging current supplied to the battery cell to charge the battery cell provided in the battery pack A charge switching unit; A discharge switching unit provided on a charging / discharging path of the battery pack and switching a discharging current supplied from the battery cell; A control unit for controlling switching operations of the charge switching unit and the discharge switching unit; And an inductor disposed on the charge / discharge path of the battery pack.

Preferably, the charge switching unit and the discharge switching unit include FETs.

Further, preferably, the charge switching unit and the discharge switching unit include a MOSFET.

Also preferably, a bypass line connected in parallel with the inductor; And a bypass switching unit for switching the current to flow through any one of the inductor and the bypass line.

More preferably, the control unit controls the bypass switching unit so that the charge current flows to the inductor before or simultaneously with turning on the charge switching unit.

Also preferably, the control unit controls the bypass switching unit so that the discharge current flows to the inductor before or simultaneously with turning on the discharge switching unit.

Also, preferably, the control unit controls the bypass switching unit so that current flows to the bypass line after a charging or discharging is started and a reference time has elapsed.

According to another aspect of the present invention, there is provided a battery pack including the battery pack management device.

According to another aspect of the present invention, there is provided a notebook computer including the above-described battery pack management device.

According to the present invention, an abrupt change of the current can be suppressed by the inductor provided on the charge / discharge path. This makes it possible to suppress a rush current that can flow initially when a discharge circuit such as a motor or a charging circuit such as a charging device or a generator is connected to the battery pack. Therefore, the rush current is not generated, and the damage or the like of the charge / discharge circuit connected to the battery pack management device itself, the battery pack, and the battery pack can be prevented.

Further, according to an embodiment of the present invention, when a bypass line is provided to bypass the inductor and is switched to an initial state of charge, an initial discharge state, a charge to a discharge state, Current is allowed to flow and after the rush current generation condition is removed, current flows to the bypass line, so that the power dissipation can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description of the invention given below, serve to further the understanding of the technical idea of the invention, And should not be construed as limiting.
1 is a view schematically showing a configuration of a conventional battery pack managing apparatus.
2 is a graph showing a change in magnitude of a current at the initial stage of discharging or charging in a conventional battery pack.
3 is a view schematically showing a configuration of a battery pack managing apparatus according to an embodiment of the present invention.
4 is a diagram schematically showing a configuration of a battery pack managing apparatus according to a more specific embodiment of the present invention.
5 is a view schematically showing a configuration of a battery pack managing apparatus according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present description and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should design the concept of the term appropriately in order to describe its own invention in the best way possible. It should be interpreted as meaning and concept consistent with the technical idea of the present invention.

Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

3 is a view schematically showing a configuration of a battery pack managing apparatus according to an embodiment of the present invention.

3, the battery pack management apparatus according to the present invention includes a discharge switching unit 300, a charge switching unit 400, a control unit 500, and an inductor 600 connected to a charge / .

The discharge switching unit 300 is provided on the charge / discharge path of the battery pack to switch a discharge current. That is, when the discharging circuit 200, which is an external circuit, is connected to the input / output terminals (Pack +, Pack-) of the battery pack, a discharging current is supplied from the battery cell 100 provided in the battery pack to the discharging circuit 200, The discharge switching unit 300 selectively opens and closes the discharge current.

The charge switching unit 400 is provided on the charge / discharge path of the battery pack to switch the charge current. That is, when the charging circuit 200, which is an external circuit, is connected to the input / output terminal of the battery pack, the charging current is supplied from the charging circuit 200 to the battery cell 100 provided in the battery pack. 400 serve to selectively open and close the charging current.

The charge switching unit 400 and the discharge switching unit 300 may be implemented as a field effect transistor (FET). More preferably, the charge switching unit 400 and the discharge switching unit 300 may be implemented as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor).

However, the present invention is not limited to the specific form of the charge switching unit 400 and the discharge switching unit 300, and the charge switching unit 400 and the discharge switching unit 300 may be applied to the discharge switching unit 300, And the like.

The control unit 500 controls switching operations of the charge switching unit 400 and the discharge switching unit 300. Particularly, the controller 500 may control the switching operations of the charge switching unit 400 and the discharge switching unit 300 in consideration of the state of the charge / discharge circuit 200 connected to the battery pack. For example, the control unit 500 controls the charging switching unit 400 and the discharging switching unit 300 so that discharging is possible when a load such as a motor is connected to the charging / discharging circuit 200, The charging switching unit 400 and the discharging switching unit 300 are controlled so that charging can be performed when a charging circuit such as a generator is connected to the battery 200. The control unit 500 may be supplied with driving power for the operation from the battery cell 100 or alternatively may be supplied with driving power from a separately provided power supply unit.

Meanwhile, as shown in the figure, a sense resistor 800 may be installed in the charge / discharge path of the battery pack. In this case, the controller 500 can monitor the charge / discharge current of the battery pack by measuring the voltage across the sense resistor. If it is detected that an overcurrent has occurred, the controller 500 may control the charge switching unit 400 or the discharge switching unit 300 to be in the off state to shut off the charging / discharging current. Alternatively, when it is detected that an overcurrent is generated, the control unit 500 may control a separate shut-off circuit installed on the charge / discharge path, such as the fuse 900 shown in the figure, to shut off the charging / discharging current.

The inductor 600 is installed on the charge / discharge path of the battery pack. This inductor 600 can suppress a sudden change of the charging current and a sudden change of the discharging current.

Here, the inductor 600 does not mean only a wire-wound coil but means an element having an inductance and satisfying the following expression (1), and may be implemented by a combination of other passive elements and active elements. An inductor implemented as a coiled coil is expensive and large in size. As an alternative, a simulated inductor that is advantageous for miniaturization can be employed. In addition, a variable inductor can be employed that can change the inductance according to the user's demand . If a variable inductor is employed, the change in inductance may be controlled by the control unit 500. [

On the other hand, for example, when the battery cell 100 is switched from a charging state in which the battery cell 100 is supplied with current from the charging circuit 200 to a discharging state in which a current is supplied to the discharging circuit 200, There is a possibility that a sudden change in flow occurs. However, according to the present invention, since the inductor 600 is provided on the charging / discharging path, the inductor 600 suppresses the abrupt change of the current, and the occurrence of the rush current can be mitigated or prevented.

Since the rush current flowing on the charging / discharging path of the battery pack mainly relates to the safety of the battery, the current is mainly described and the current will be mainly described below. However, since the above description can be applied to the voltage as it is, the inductor 600 is installed on the charge / discharge path of the battery pack, so that the rush voltage can be prevented.

Hereinafter, the present invention will be described in more detail with reference to other examples.

4 is a diagram schematically showing a configuration of a battery pack managing apparatus according to a more specific embodiment of the present invention. Referring to FIG. 4, the charge switching unit 400 and the discharge switching unit 300 may be implemented as FETs, particularly MOSFETs.

The FET is divided into two types, JFET and MOSFET, and it is controlled by the voltage to determine whether to form a channel.

The FET may include FET bodies 301 and 401 and parasitic diodes 302 and 402 connected in parallel thereto. Since the parasitic diodes 302 and 402 have a characteristic similar to that of a general diode, they have a rectifying action. When the overcurrent flows through the parasitic diodes 302 and 402 because of high resistance, the temperature is increased by Joule's heat And the peripheral circuit elements as well as the FET main bodies 301 and 401 may be damaged.

4, the N-type MOSFET is used to implement the charge switching unit 400 and the discharge switching unit 300. However, the present invention is not limited thereto, and the P-type MOSFET A variety of transistors with parasitic diodes may be employed. Since the operation principle of the MOSFET is obvious to those of ordinary skill in the art, a detailed description of the operation principle of the MOSFET will be omitted and the charging and discharging currents flowing through the FET bodies 301 and 401 and the parasitic diodes 302 and 402 connected in parallel thereto And the flow of

First, when the battery pack is switched from a rest state or a discharge state to a charged state, the controller 500 applies a voltage to the gate of the charge switching unit 400, that is, the gate of the charge FET body 301. When a voltage is applied to the gate of the charging FET body 301, a channel is formed between the drain and the source, and the charging FET body 401 is turned on so that a charging current flows in the charging / discharging path of the battery pack do. At this time, when the discharge FET main body 301 is turned off and the charging FET main body 401 is turned on, the charging current flows through the parasitic diode 302 of the discharging FET along the C path shown by the one- Lt; / RTI >

Therefore, if an overcurrent flows as a charging current, such an overcurrent flows to the parasitic diode 302 of the discharging FET, and the discharging FET can be damaged. Particularly, in the process of switching to the charging state, a rush current having a current value higher than a normal charging current can flow. Due to the rush current, an overcurrent can flow into the parasitic diode 302 of the discharging FET within a short time. In this case, the discharge FET or the like may be damaged by the heat generated by the high resistance characteristic of the parasitic diode 302 included in the discharge FET. However, according to the present invention, since the overcurrent is prevented from flowing as the charging current by the inductor 600 installed on the charging / discharging path of the battery pack, a large current does not flow to the parasitic diode 302 of the discharging FET, Damage can be prevented.

Next, when the battery pack is switched from the idle state or the charging state to the discharging state, the control unit 500 applies the voltage to the discharging switching unit 300, i.e., the gate of the discharging FET body 301. [ When a voltage is applied to the gate, a channel is formed between the drain and the source, the discharge FET body 301 is turned on, and a discharge current flows through the charge / discharge path of the battery pack. At this time, when the charging FET main body 401 is turned off and the discharge FET main body 301 is turned on, the discharging current flows through the parasitic diode 402 of the charging FET along the D path shown by the two- Lt; / RTI >

 Therefore, when an overcurrent flows as a discharge current, such an overcurrent can flow to the parasitic diode 402 of the charge FET. In particular, a rush current may flow during the initial discharge or in the process of switching from charge to discharge, thereby allowing an overcurrent to flow through the parasitic diode 402 of the charge FET within a short time. In this case, the charging FET or the like may be damaged by the heat generated by the high resistance characteristic of the parasitic diode 402. However, according to the present invention, since the overcurrent is prevented from flowing as the discharging current by the inductor 600 installed on the charging / discharging path of the battery pack, damage of the charging FET and the like can be prevented.

The inductance of the inductor 600 can be determined in consideration of various conditions such as the expected magnitude of the rush current and the specification of the battery pack. Advantageously, when the variable inductor is employed as the inductor 600, there is an advantage that it can be easily adapted to the charge / discharge circuit 200 and the surrounding environment.

Preferably, the battery pack managing apparatus according to the present invention may further include a detour line. This will be described in more detail with reference to FIG.

5 is a view schematically showing a configuration of a battery pack managing apparatus according to another embodiment of the present invention.

Referring to FIG. 5, there is a difference in that a bypass line connected in parallel to the inductor 600 is further provided, as compared with FIG. Therefore, detailed description of components common to the embodiment shown in FIG. 4 will be omitted, and a bypass line, which is a new component, will be mainly described.

The bypass line (R) is connected in parallel with the inductor (600) so that current can flow along the bypass line (R) without passing through the inductor (600).

The inductor 600 provided on the charging / discharging path has an effect of suppressing the occurrence of the overcurrent in the charge / discharge switching process, but after the rush current is removed, the inductor 600 interrupts the smooth flow of the current as an impedance component. In particular, when a constant current flows through the charging / discharging path, ideally, the impedance component of the inductor 600, such as a coil, should be zero, but actually it has an impedance component, It is also difficult to have a completely constant value. Therefore, after the rush current generation condition is removed, it is preferable that the charge / discharge current flows through the bypass line (R).

For example, when the charging state or the discharging state is maintained after the charge / discharge switching state, both the charging FET main body 401 and the discharging FET main body 301 are turned on so that current flows through the FET main bodies 301 and 401 . In this case, since the charging or discharging current does not flow through the parasitic diodes 302 and 402, there is little possibility that the charging FET or the discharging FET is damaged by overheating. Rather, in this state, a smooth current flow is required, so reducing the impedance component may be advantageous in terms of power efficiency.

As described above, in the embodiment where the bypass line R is provided, the battery pack managing apparatus may further include a bypass switching unit 700, as shown in FIG.

The bypass switching unit 700 switches the charging / discharging current flowing in the battery pack to selectively flow to the inductor 600 or the bypass line R. [ The switching operation of the bypass switching unit 700 may be controlled by the control unit 500. That is, the control unit 500 can control whether the charging / discharging current flows through the bypass line R connected in parallel or through the inductor 600 through the bypass switching unit 700.

For example, when switching from the idle state or the discharging state to the charging state, the control unit 500 controls the detour switching unit 700 before or during the turn-on of the charge switching unit 400, The path through which the current flows can be made to pass through the inductor 600. According to this embodiment, even if the charge switching unit 400 is turned on, the charge current flows to the inductor 600, so that no rush current is generated due to the start of charging. Therefore, damage of the discharge switching part 300 due to the rush current can be prevented.

Similarly, when switching from the idle state or the charged state to the discharged state, the controller 500 controls the bypass switching unit 300 so that the discharge current flows to the inductor 600 before or at least simultaneously with the turn- (700). According to this embodiment, when switching to the discharge state, current can pass through the inductor 600, and the occurrence of the overcurrent due to the rush current can be suppressed.

Also, the control unit 500 may control the bypass switching unit 700 so that current flows to the bypass line R after the discharge or charging starts and the reference time has elapsed. Here, the reference time may be set to a time required to discharge the rush current generated at the time of discharging or start of charging, and may be determined by experiments and may be set differently depending on various conditions such as the environment of the battery pack. After reaching the reference time, the rush current does not occur unless there is a special condition. Therefore, it is preferable that the current flows through the bypass line R as in this embodiment.

Alternatively, it is also possible that current flows through the bypass line (R) when the FET bodies (301, 401) are all turned on and the current no longer flows through the parasitic diodes (302, 402).

More preferably, the above embodiments can be combined. That is, when switching to the charging state or the discharging state, the bypass switching unit 700 is controlled so that the charging / discharging current flows to the inductor 600 in advance or simultaneously. When the reference time passes after the charging or discharging is started, The bypass switching unit 700 may be controlled to control the bypass switching unit 700 so that current flows through the bypass line R when the FET bodies 301 and 401 are all turned on.

In addition, the control unit 500 may control the detour switching unit 700 by various methods. For example, when the state of the charging / discharging circuit 200 is unstable and the change of the current is large, the controller 500 can cause the current to flow to the inductor 600 rather than the bypass line R. [ That is, the control unit 500 can appropriately select whether or not to use the bypass line R and how to use it in consideration of the state of the charge / discharge circuit 200, which is an external circuit.

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. It will be understood that various modifications and changes may be made without departing from the scope of the appended claims.

In the present specification, the term " part " such as a " control part ", a " switching part ", or the like is used, but it is a logical constitutional unit and not necessarily an element that can be physically separated. Lt; RTI ID = 0.0 > art. ≪ / RTI >

100: Battery cell
200: charge / discharge circuit
300: discharge switching unit
400: Charge switching section
301, 401: FET body
302, 402: parasitic diode
500:
600: Inductor
700: bypass switching part
800: Sense resistance
900: Fuse

Claims (9)

The battery pack is provided with a charging and discharging path of a battery pack and switches a charging current supplied to the battery cell to charge the battery cell of the battery pack, A charge switching unit including an FET including a parasitic diode;
And a FET having a parasitic diode disposed on the charge / discharge path of the battery pack and capable of switching a discharge current supplied from the battery cell and conducting a reverse current opposite to the direction of the discharge current, A discharge switching unit;
A control unit for controlling switching operations of the charge switching unit and the discharge switching unit; And
An inductor provided on a charging / discharging path of the battery pack,
The battery pack management apparatus comprising: delete The method according to claim 1,
Wherein the charge switching unit and the FET of the discharge switching unit are MOSFETs. The method according to claim 1,
A bypass line connected in parallel with the inductor; And
A bypass switching part for switching the current to flow through any one of the inductor and the bypass line,
The battery pack management device further comprising: 5. The method of claim 4,
Wherein the control unit controls the bypass switching unit so that the charge current flows to the inductor before or simultaneously with turning on the charge switching unit. 5. The method of claim 4,
Wherein the control unit controls the bypass switching unit so that the discharge current flows to the inductor before or simultaneously with turning on the discharge switching unit. 5. The method of claim 4,
Wherein the control unit controls the detour switching unit so that a current flows to the bypass line after a charging or discharging is started and a reference time has elapsed. A battery pack comprising the battery pack management device according to any one of claims 1 to 7. A notebook computer comprising the battery pack management device according to any one of claims 1 and 3 to 7.

Images