A new battery parameter identification considering current, SOC and Peukert's effect for hybrid electric vehicles

Abstract

This paper proposes a battery model which considers battery current, SOC (state of charge) and Peukert's effect. The proposed battery model is a simplified Randles equivalent circuit, and battery parameters are extracted from pulsed current tests by applying recursive least square method and curve fitting method. The extracted parameters are used in the two-dimensional look up table of battery current and SOC. In addition, the model includes Peukert's effect to compensate SOC change in terms of battery current level, and thus operate accurately with a wide range of charge/ discharge current. The battery model is implemented for NiMH Panasonic HHR650D and compared with discharge curves in case of several current levels ranged from 0.1C to 5C. The proposed model is validated by adding it on PSAT (Powertrain System Analysis Toolkit) environment for HEV application.