METHOD AND APPARATUS FOR ESTIMATION OF STATE OF CHARGE USING SLIDING MODE OBSERVER

摘要

A method and an apparatus for estimating an SOC(State Of Charge) of a secondary battery using a sliding mode observer are provided to dynamically estimate the accurate SOC of the secondary battery at various temperature and conditions by using a minimum parameter. An apparatus for estimating an SOC of a secondary battery(B) using a sliding mode observer(100) includes a storage medium(150), a current/voltage detecting unit, and a microprocessor(130). The storage medium stores parameters of state equations for secondary battery output voltage, capacitor voltage, and the SOC, which are induced by RC circuit modeling in consideration of open circuit voltage of the secondary battery, a capacitor component by battery polarization, and a resistance component inside the battery, a positive feedback gain constant of the sliding mode observer, SOC tables by open circuit voltages, and a secondary battery state estimating program. The current/voltage detecting unit measures input current and output voltage of the secondary battery at sampling time. The microprocessor loads the secondary battery state estimating program, the parameter, the positive feedback gain constant, and the SOC tables by open circuit voltages in a memory(140) and calculates an SOC estimate of the secondary battery by using the parameter, the positive feedback gain constant, and the SOC tables by open circuit voltages.