Battery pack modeling for the analysis of battery management system of a hybrid electric vehicle

Battery forms a critical part of the hybrid electric vehicle (HEV) drivetrain. An important constraint to the effective performance and reliability of the battery is its unpredictable internal resistance variation along the driving cycle. Temperature has a considerable effect on this internal resistance and thus the battery management system monitors cell and battery pack temperature in accordance with the state-of-charge to prevent thermal runaway. Li-ion batteries which offer possible solutions to the HEVs energy and power density demands thus need to have a good thermal management system in order to enhance their performance. This paper aims to develop a battery pack model that would analyze the variation of internal resistance as a function of temperature. The study of the losses would help in designing a cost effective efficient battery management system.