Thermal modeling of an on-board nickel-metal hydride pack in a power-split hybrid configuration using a cell-based resistance-capacitance, electro-thermal model

Presented study discusses the development of a finite differencing (FD) thermal model for a power-split hybrid configuration employing a nickel-metal hydride battery pack. A resistance-capacitance electro-thermal model is used to couple the experimental boundary conditions (current, voltage, state of charge, and temperature) with the modeled battery resistance to capture its electro-chemical behavior and the cell exothermic reactions. Battery current, voltage, and temperature (discrete and full field) for a vehicle with a power-split hybrid configuration were collected under different standard (Federal Highway Driving Schedule and Federal Urban Dynamometer Driving Schedule (FUDS)) and artificially generated driving cycles. This manuscript analyzes the battery current and voltage in relation to vehicle speed and shows how the proposed FD model predicts the spatial and temporal temperature profiles of the power train in good agreement with the vehicle data as reported by the on-board diagnostics module.