A unique control strategy to improve the life cycle of the battery and to reduce the thermal runaway for electric vehicle applications.

This paper presents a unique thermal control strategy to improve the ageing of the battery and to maintain the internal temperature of the battery within the optimum limit of 20 °C–40 °C for electric vehicle (EV) applications. The hybrid EV system encompasses photovoltaic (PV) module, high power density device supercapacitor (SC) and high energy density Li-ion battery (LIB) as an energy storage element. The vehicle dynamics encounter frequent voltage fluctuations in the direct current (DC) bus, which ultimately reduces the lifecycle of the battery and also the heat is generated inside the battery when it is connected in parallel to the DC bus. The frequent charging/discharging of LIB is controlled by the unique thermal control strategy of the hybrid EV system. The DC bus voltage is controlled by the SC bi-directional converter (BDC) where, the battery BDC delivers the essential constant current from the main source (PV) to the DC bus. This unique thermal control strategy supports the distribution of power from the PV/LIB/SC hybrid source system to the EV and also improves the battery life cycle. Due to constant charging/discharging of battery the thermal runaway (TR) problem such as leak, smoke, gas venting, rapid disassembly, flames etc., can be eliminated. Decoupling of load power and battery power comprises the growth in the battery lifecycle and to maintain the optimum internal temperature of the LIB by conditional flow of current through hybrid thermal management system (HTMS). To certify the thermal control strategy and to estimate the performance of HTMS, a simulation of a hybrid source system with vehicle dynamics is performed in MATLAB/Simulink. Numerical analysis of the LIB during constant charging/discharging is performed using ANSYS fluent software to validate the temperature effect of HTMS. [ABSTRACT FROM AUTHOR]