State of Charge Estimation in Rechargeable Batteries

R.H.MILOCCO; J. E. THOMAS; E. B. CASTRO

Mar del Plata

Congreso; IV Congreso Nacional-3er Congreso Iberoamericano de hidrógeno y Fuentes Sustentables de Energía-HYFUSEN2011; 2011

Instituto de Energía y Desarrollo Sustentable IEDS-CNEA y UTN

In this work we estimate the state of charge (SOC) of Ni-MH rechargeable batteries using a robust optimalfilter based on a simplified electrochemical model. The robust filter guarantees that the upper boundvariance of the error be minimum for all admissible uncertainties. First, we briefly describe the completeelectrochemical model of the NiMH battery. The full model is further reduced in a cascade of two parts, asimple integrator followed by a static nonlinearity. The inverse of the static nonlinearity works as a sensorsoftware in such a way that its output is filtered with the robust filter to obtain SoC estimations. Experimentalresults with commercial batteries are provided to illustrate the estimation procedure and to show theperformance.