Design and Verification of a Model-less Approach for Maintaining Battery Safe Operation in Electric Vehicle Using Hardware-in-the-Loop Simulation

This paper presents a method for maintaining the battery safe operating voltage region in a hybrid electric vehicle. Using the instantaneous value for the battery voltage in the proposed method, the traction motor maximum torque is limited through an interaction between the BMS and vehicle control unit. Unlike the methods based on battery State of Power (SoP) estimation in which the battery safe operation cannot be guaranteed because of the model-based nature, performance of the proposed method does not rely on the precision of battery modelling and can be used in different life conditions for the battery. In addition, due to low computational costs, the proposed algorithm can be easily implemented on the BMS. Performance of the designed algorithm has been evaluated in a Hardware-in-the-Loop (HiL) test bench for a series hybrid electric bus and compared with the results of SoP estimation based methods. Results indicate the improvement towards maintaining the safe operating voltage region in various life conditions for the battery.