KR20150015970A - Battery management system preventing any problems that occur when a signal line is short to the high voltage or ground voltage and control method thereof - Google Patents

Abstract

The present invention relates to a battery management system capable of preventing a problem generated when a signal line is high voltage or is grounded and disconnected and a control method thereof. The battery management system according to the present invention comprises; a master unit which outputs a starting signal; a slave unit wherein a starting state is controlled by the starting signal of the master unit; and a starting signal line which connects the master unit and the slave unit and delivers the starting signal of the master unit to the slave unit. The battery management system additionally comprises a capacitor connected to the starting signal.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a battery management system and a control method thereof that can prevent a problem that a signal line may be generated when a high voltage or a short- }

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a battery system and a control method thereof, and more particularly, to a battery management system and a control method thereof capable of preventing a problem that a signal line may cause when a high voltage or a short circuit occurs.

Secondary batteries having high electrical characteristics such as high energy density and high ease of application according to the product group can be applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by electric driving sources, Storage devices (Energy Storage System) and so on. Such a secondary battery is not only a primary advantage that the use of fossil fuel can be drastically reduced, but also produces no by-products resulting from the use of energy, and thus is attracting attention as a new energy source for enhancing environmental friendliness and energy efficiency.

The battery pack applied to the electric vehicle has a structure in which a plurality of cell assemblies including a plurality of unit cells are connected in series in order to obtain high output. The unit cell includes a positive electrode and a negative electrode current collector, a separator, an active material, an electrolyte, and the like, and can be repeatedly charged and discharged by an electrochemical reaction between the components.

In addition to such a basic structure, the battery pack may further include a power supply control for a driving load of a motor or the like, an electric characteristic value measurement such as a current or a voltage, a charging / discharging control, a voltage equalization control, And a BMS (Battery Management System) for monitoring and controlling the state of the secondary battery by applying an algorithm for estimation and the like.

In recent years, there has been a growing demand for a multi-module battery pack in which a plurality of battery modules are connected in series and / or in parallel with each other as a need for a large-capacity structure increases.

Since the battery pack of such a multi-module structure includes a plurality of battery cells, there is a limitation in controlling the charging / discharging state of all the battery cells using one BMS. Therefore, recently, a battery management unit (BMU) is installed for each battery module included in the battery pack, one of the BMUs is designated as a master BMU, remaining BMUs are designated as a slave BMU, A technique for controlling charge and discharge of each battery module is used. Such a slave BMU normally waits in a sleep state, and starts its operation by the control signal of the master BMU.

As a conventional technique related to the master-slave method, Korean Patent Laid-Open Publication No. 10-2011-0013747 confirms that a master BMU and a slave BMU are connected by a simple signal line. However, when the master BMU and the slave BMU are connected by a simple signal line as in the prior art, problems caused by internal or external influences can not be prevented.

1 is a block diagram schematically showing a configuration in which a master BMU and a slave BMU are connected by a simple signal line according to a related art.

Referring to FIG. 1, it can be seen that one master BMU 10 and a plurality of slave BMUs 11 are connected by a signal line 12. The master BMU 10 outputs a signal for controlling the state of the slave BMU 11 to sleep or wake up through the signal line 12. [ For example, when the control signal outputs a high logic level signal, the state of the slave BMU 11 goes to sleep. When the control signal outputs a low logic level signal, the state of the slave BMU 11 is wake-up.

On the other hand, it is assumed that the signal line 12 is short-circuited to a high voltage (for a dotted line) or shorted to a ground voltage (for a dotted line) for some reason.

FIG. 2 is a conceptual diagram of a control signal showing a problem that a signal line may be generated at a high voltage or a short-circuited ground.

2 (a) shows a case where the signal line is short-circuited to a high voltage. Referring to FIG. 2 (a), a high voltage is continuously applied to the signal line, and the slave BMU is changed to a sleep state without being desired. Furthermore, some or all of the system may be destroyed by the high voltage.

2 (b) shows a case where the signal line is short-circuited to the ground voltage. Referring to FIG. 2 (b), since a high logic level voltage can not be applied to the signal line, the slave BMU can not be changed to the sleep state.

Accordingly, there is a need for a battery management system and a control method thereof that can prevent a problem that a signal line may be generated when a high voltage or a short circuit occurs.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a battery management system and a control method thereof that can prevent a problem that a signal line may be generated when a high voltage or a short circuit occurs.

According to an aspect of the present invention, there is provided a battery management system including a master unit for outputting a start signal; A slave unit whose start-up state is controlled by a start signal of the master unit; And a start signal line connecting the master unit and the slave unit and transmitting a start signal of the master unit to the slave unit, the system further comprising a capacitor connected to the start signal line.

According to an embodiment of the present invention, when the slave unit receives the start signal indicating the start state without changing more than the predetermined start state holding time, the slave unit changes the start state.

The master unit according to the present invention can output a start signal having a pulse of a predetermined occurrence time. At this time, the duration of the pulse is shorter than the time when the voltage across the capacitor reaches a voltage capable of changing the starting state of the slave unit and can change the starting state of the slave unit.

A battery management system according to the present invention includes: a battery management system; And a plurality of battery cells connected to the master unit or the slave unit.

A battery pack according to the present invention includes: a battery pack; And a load that is supplied with electric power from the battery pack. At this time, the load may be an electric driving means or a portable device.

According to another aspect of the present invention, there is provided a method of controlling a battery management system, the method comprising: receiving a start signal for controlling a start state of a slave unit through a start signal line connected to a capacitor; (a) setting and storing a pulse generation time and a pulse duration time in the master unit; And (b) the master unit outputs a start signal to the slave unit by a pulse having the set time and duration.

The control method of the battery management system according to the present invention may further include the step of: (c) changing the startup state when the always-on slave unit receives the startup signal indicating the startup state without change of the startup state holding time or more .

In this case, the duration of the pulse is shorter than the time at which the voltage across the capacitor reaches a voltage capable of changing the starting state of the slave unit and can change the starting state of the slave unit. In addition, the generation time of the pulse is shorter than the start-up state holding time.

According to an aspect of the present invention, it is possible to prevent a problem that may occur when the startup signal line is short-circuited by a high voltage. Particularly, it is possible to prevent the device included in the battery management system from being destroyed by the high voltage.

According to another aspect of the present invention, it is possible to prevent a problem that may occur when the startup signal line is short-circuited by the ground voltage. In particular, it is possible to prevent the startup state of the slave unit from being changed by the ground voltage.

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 block diagram schematically showing a configuration in which a master BMU and a slave BMU are connected by a simple signal line according to a related art.
FIG. 2 is a conceptual diagram of a control signal showing a problem that a signal line may be generated at a high voltage or a short-circuited ground.
3 is a block diagram schematically illustrating the configuration of a battery management system according to an embodiment of the present invention.
4 is a conceptual diagram showing the startup state of the slave unit according to the startup signal.
5 is a conceptual diagram showing a start signal having a pulse and a state of the slave unit according to the present invention.
6 is a conceptual diagram showing a delay of a start signal by a capacitor.

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 specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately It should be interpreted in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined. 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 block diagram schematically illustrating the configuration of a battery management system 100 according to an embodiment of the present invention.

3, the battery management system 100 according to the present invention includes a master unit 110, a slave unit 111, and a start signal line 112.

The master unit 110 and the slave unit 111 are battery management units for controlling a plurality of battery cells. The master unit 110 and the slave unit 111 are used for controlling power supply to a driving load of a motor or the like by a battery cell, measuring electrical characteristic values such as current or voltage, charging / discharging control, An algorithm for estimation of SOC (State Of Charge) is applied to monitor and control the state of the battery cell to configure a battery management system.

The battery management system 100 according to the present invention uses a technique of controlling charge / discharge of each battery module by a master-slave method. Therefore, the slave units 111 normally wait in a sleep state, and start the operation by the control signal of the master unit 110. [ 3 illustrates an example in which the battery cells 120 are connected only to the slave unit 111, the present invention is not limited to the above example.

The type of the battery cell 120 is not particularly limited. Each battery cell 120 may be composed of a lithium ion battery, a lithium polymer battery, a nickel cadmium battery, a nickel hydride battery, a nickel zinc battery, or the like, which can be recharged and take charge or discharge voltage into consideration. In addition, the plurality of battery cells 120 may be connected in series or in parallel to constitute a battery pack 121. At this time, the number of the battery cells 120 included in the battery pack 121 may be variously set according to a required output voltage or a charging capacity. However, the present invention is not limited by the type of the battery cell 120, the output voltage, the charging capacity, and the like. 3, all of the battery cells 120 are connected in series. However, the present invention is not limited by the connection method of the battery cells 120. [0053] FIG.

The startup signal line 112 connects the master unit 110 and the slave unit 111. The start signal line 112 transmits a start signal of the master unit 110 to the slave unit 111. FIG. 3 shows an embodiment in which only the master unit 110 and the first slave unit 111 are directly connected, but the present invention is not limited to the above embodiment. All of the slave units 111 may be connected to the master unit 110 and a small number of the slave units 111 may be connected to one slave unit 111 and the master unit 110 It is possible.

Although the start signal line 112 will be described as a line for transmitting a start signal in the present specification, the start signal line 112 is not limited to the start signal, and the master unit 110 may be connected to the slave unit 111 It is also possible to transmit various control signals for controlling the operation or various data signals for reporting the status of the battery cells 120 managed by the slave unit 111. [

The battery management system 100 according to the present invention includes capacitors 113 and 114 connected to the start signal line 112. In the present specification, the capacitors 113 and 114 included in the master unit 110 and the slave unit 111 located at the lowest position will be mainly described. However, the same capacitors play the same role in other slave units (units 2 to n) It is self-evident.

It is possible to prevent a problem from occurring when the startup signal line 112 is short-circuited to the high voltage by the capacitors 113 and 114. As in the case of FIG. 2 (a), suppose that the startup signal line 112 is shorted to a high voltage. At this time, the capacitors 113 and 114 will be charged, and the voltages across the capacitors 113 and 114 become equal to the high voltage. Therefore, it is possible to prevent the problem that the devices included in the battery management system 100 are destroyed because the current of the high voltage no longer flows.

On the other hand, the slave unit 111 according to the present invention changes the starting state upon receiving a control signal indicating the starting state equally over a predetermined time. It is obvious that the startup signal line 112 connected by the capacitors 113 and 114 can prevent a problem due to a high voltage short circuit but prevents a problem that occurs when the startup signal line 112 is short- Can not. Accordingly, when the slave unit 111 receives a signal that maintains the starting state without changing the preset starting state holding time, it determines that the slave unit 111 has failed.

To explain this in more detail, I will first explain the following points. In one example, the start signal has a high logic level signal and a low logic level signal. The slave unit 111 maintains the sleep state in the signal of the high logic level and the slave unit 111 is changed to the start state in the signal of the low logic level. The voltages of the high logic level and the low logic level may be variously set, and for example, the high logic level may be set to 5V and the low logic level may be set to 0V.

4 is a conceptual diagram showing the startup state of the slave unit 111 according to the startup signal.

Referring to FIG. 4, it can be seen that the logic level of the startup signal is shown above and the startup state of the slave unit 111 is indicated below. First, it can be seen that the start signal maintains a low logic level without change. In this case, the start signal line 112 may be shorted to the ground voltage. Accordingly, when the slave unit 111 receives the low logic level without changing during the preset starting state holding time Th, it determines that the startup signal line 112 is short-circuited to the ground voltage. Therefore, the slave unit 111 changes the start state to the sleep state regardless of the start signal. It is obvious that the starting state holding time Th can be set in various ways in advance.

The capacitors 113 and 114 connected to the start signal line 112 and the start time holding time Th of the slave unit 111 cause the start signal line 112 to be short circuited to the high voltage or the ground voltage Problems that can be avoided. Meanwhile, the master unit 110 needs a control signal to maintain the slave unit 111 in the starting state for a desired time. That is, as in the prior art, simply keeping the signal of low logic level continuously can not keep the slave unit 111 in the starting state for a desired time.

To solve this problem, the master unit 110 according to the present invention can output a start signal having a pulse.

5 is a conceptual diagram showing a start signal having a pulse and a state of the slave unit 111 according to the present invention.

Referring to FIG. 5, the start signal has a pulse. The pulse has a preset generation time Ta and a predetermined duration Tb.

The occurrence time Ta is shorter than the start state holding time Th. The reason why the generation time Ta is shorter than the startup state maintenance time Th is that the slave unit 111 changes the startup state to the sleep state after the startup state maintenance time Th has passed To prevent it.

The duration Tb of the pulse reaches a voltage at which the both ends of the capacitors 113 and 114 can change the starting state of the slave unit 111 to change the starting state of the slave unit 111 It is shorter than the time available.

6 is a conceptual diagram showing the delay of the start signal by the capacitors 113 and 114. Fig.

Referring to FIG. 6, it can be confirmed that the slave unit 111 is in an activated state by the low logic level of the start signal. It can be confirmed that the start signal is changed from the low logic level to the high logic level, but the startup state of the slave unit 111 is not changed to the sleep state immediately. It can be confirmed that the startup state of the slave unit 111 is changed to the sleep state after the sleep delay time Td has elapsed. The sleep delay time Td is a phenomenon generated by the capacitors 113 and 114 connected in series with the start signal line 112. That is, the time required for charging both ends of the capacitors 113 and 114 until the voltage becomes the high logic level voltage.

5, the duration Tb of the pulse is shorter than the sleep delay time Td, but the slave unit 111 can be kept in the sleep state without being changed to the sleep state.

The battery management system 100 according to the present invention includes a battery management system 100 and a battery pack 121 including a plurality of battery cells 120 connected to the master unit 110 or the slave unit 111 It can be a component.

The battery pack 121 according to the present invention may be a component of a battery driving system including a load supplied with power from the battery pack 121 and the battery pack 121. [

Examples of the battery driving system include an electric vehicle (EV), a hybrid vehicle (HEV), an electric bicycle (E-Bike), a power tool, an energy storage system, an uninterruptible power supply (UPS) A battery pack, a portable computer, a portable telephone, a portable audio device, a portable video device, and the like. An example of the load is a power supplied from a motor or a battery pack, And may be a power conversion circuit for converting the power into a required power.

According to the present invention, it is possible to prevent a problem that may occur when the startup signal line is short-circuited by a high voltage. Particularly, it is possible to prevent the device included in the battery management system from being destroyed by the high voltage. In addition, it is possible to prevent a problem that may occur when the startup signal line is short-circuited by the ground voltage. In particular, it is possible to prevent the startup state of the slave unit from being changed by the ground voltage.

In the meantime, in describing the present invention, each component of the present invention shown in FIG. 3 should be understood as a logical component rather than a physically separated component.

That is, since each configuration corresponds to a logical component for realizing the technical idea of the present invention, even if each component is integrated or separated, if the functions performed by the logical configuration of the present invention can be realized, And it is to be understood that any component that performs the same or similar function should be construed as being within the scope of the present invention irrespective of the consistency of the name.

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 to be limited to the details thereof and that various changes and modifications will be apparent to those skilled in the art. And various modifications and variations are possible within the scope of the appended claims.

100: Battery management system
110: Master unit
111: Slave unit
112: Start signal line
113 and 114: capacitors
120: Battery cell
121: Battery pack

Claims (12)

A master unit for outputting a start signal;
A slave unit whose start-up state is controlled by a start signal of the master unit; And
And a start signal line for connecting the master unit and the slave unit and transmitting a start signal of the master unit to the slave unit,
And a capacitor connected to the start signal line. The method according to claim 1,
Wherein the slave unit changes the starting state upon receiving a start signal indicating a starting state without any change in the starting state holding time set in advance. 3. The method of claim 2,
Wherein said master unit outputs a start signal having a pulse of a predetermined generation time. The method of claim 3,
Wherein the duration of the pulse is shorter than a time at which the voltage across the capacitor reaches a voltage capable of changing the starting state of the slave unit and can change the starting state of the slave unit. The method of claim 3,
Wherein the generation time of the pulse is shorter than the startup state maintenance time. A battery management system according to any one of claims 1 to 5, And
And a plurality of battery cells connected to the master unit or the slave unit. A battery pack according to claim 6. And
And a load supplied with power from the battery pack. 8. The method of claim 7,
Wherein the load is an electric drive means or a portable device. A control method of a battery management system in which a master unit outputs a start signal for controlling a start state of a slave unit through a start signal line connected to a capacitor,
(a) setting and storing the pulse generation time and pulse duration in the master unit; And
(b) the master unit outputs a start signal to the slave unit by a pulse having the set time and duration. 10. The method of claim 9,
(c) when the always-on slave unit receives a start signal indicating a start-up state without any change in the start-up state holding time or more beforehand, changing the start-up state. 11. The method of claim 10,
Wherein the duration of the pulse is shorter than the time at which the voltage across the capacitor reaches a voltage that can change the starting state of the slave unit and can change the starting state of the slave unit. Control method. 11. The method of claim 10,
Wherein the generation time of the pulse is shorter than the startup state maintenance time.

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