Patent Application
20080086247
For a better understanding of the nature and objects of the present invention, reference should be made to the following detailed description with the accompanying drawings, in which:
Reference will now be made in detail to the preferred embodiment of the present invention, examples of which are illustrated in the drawings attached hereinafter, wherein like reference numerals refer to like elements throughout. The embodiments are described below so as to explain the present invention by referring to the figures.
As discussed above, in one aspect, the present invention provides A battery management system for a vehicle, comprising a plurality of slave control units, each of which manages a state of charge of a corresponding battery cell, and a master control unit interfacing with the slave control units to manage a state of charge of all the battery cells.
In case where a number of battery cells equal to K are connected in series so as to increase electric energy and power performance, it is preferable that the batter y management system includes a master control unit and a plurality of slave control units in order to conduct battery management operation more efficiently.
More particularly, the master control unit manages all of the batteries, and each of the slave control units manages a corresponding battery among the batteries. This battery management system can achieve reliable and efficient management of both all of the battery cells and subgroups batteries.
In detail, the master control unit 30 includes a current sensing unit 301, which detects the representative current value of all battery cells, a master controller 300, which controls ON/OFF operations of the slave control units and manages the SOC of all battery cells, and an interface unit 302, which is provided to interface with the slave control units.
Furthermore, each slave control unit 31 may comprise a power controller 311, which turns on/off power depending on a slave ON/OFF control signal transmitted from the master controller 300, and a voltage sensing unit 312, which detects the voltage value of a corresponding one among the predetermined number of electric energy sources, for example, four battery cells. The slave control unit 31 may further comprise a balancing maintenance unit 313, which operates an equalization circuit of the corresponding battery cell, a temperature sensing unit 314, which detects the temperature of the corresponding battery cell, a slave controller 310, which manages the SOC of the corresponding battery cell, and an interface unit, which is provided to interface with the master control unit 30.
As shown in
When the representative current value is transmitted to each slave controller 310 from the master controller 300, the slave controller 310 conducts a safety test that determines whether the ratio of voltage to present current is suitable for conducting a normal charging or discharging operation by comparing the voltage value detected by the voltage sensing unit 312 with the representative current value.
Furthermore, each slave controller 310 calculates the SOC and a power value of the corresponding battery cell with reference both to the voltage value detected by the voltage sensing unit 312 and to the temperature detected by the temperature sensing unit 314, and transmits the results to the master controller 300 through the interface unit 316.
The master controller 300 receives the SOCs and the power values from the slave controllers 310 (S12) and determines the SOC and the power value of all battery cells with reference to the SOCs and the power values of the slave controllers 310 (S13).
After the SOC and the power value of all battery cells are determined, the master controller 300 transmits the SOC and power value of all battery cells to a hybrid control unit (HCU) (S14), such that the determination of a traveling mode and overall vehicle conditions can be normally controlled by the HCU.
Furthermore, the HCU transmits information about vehicle traveling conditions to the master controller 300 such that battery charging or discharging operation is correctly conducted. For example, in case where the master controller 300 receives information about vehicle traveling conditions corresponding to a parking operation (S15), the master controller 300 outputs individual ON/OFF control signals for the slave control units 31 (S16), thus preventing high voltage battery power from being discharged.
Therefore, the master controller 300 can reliably conduct the intended function of the battery management system that provides the SOC and power value of all battery cells to the HCU. Furthermore, the master controller 300 appropriately controls ON/OFF operations of the slave control units in consideration of information about the traveling conditions of the vehicle.
In addition, as shown in
In addition, the slave control units may preferably use communication paths that are insulated from the master control unit, so that insulation between a high voltage system and a low voltage system of 12V can be ensured. Thus, a circuit design can be implemented more stably and easily.
As is apparent from the foregoing, the present invention provides a battery management system for hybrid electric vehicles or fuel cell electric vehicles, which can efficiently and stably conduct battery management. Also, since the battery management system has a simple structure, it can reduce the-manufacturing costs and simplify the design.
The invention has been described in detail with reference to preferred embodiments thereof. However, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2006-0098310 | Oct 2006 | KR | national |
