Performance Analysis of Power Sharing Control Strategies for Battery/Ultracapacitor Hybrid Energy Storage Based Electric Vehicle

摘要

Electric Vehicles (EVs) gaining demand worldwide, still face the challenge of adapting the Energy Storage System (ESS) with high power and energy density. Such an ESS is essential for providing desirable dynamic performance and driving range. The power demand from the ESS varies frequently in a wide range in an urban drive due to frequent stops and starts of the vehicle. This paper proposes an ESS with a hybrid combination of battery and ultracapacitor (UC) along with two power sharing control strategies which assures the desirable EV performance in an urban drive cycle. This proposed hybrid ESS (HESS) also leads to the improvement in the battery cycle life, dynamic response as well as energy efficiency of the EV. This work encompasses the details of the proposed control strategies viz. 'Speed Related Control' (SRC) and 'Fuzzy Based Control' (FBC). The simulation results show that the performance of FBC is better in limiting and leveling the battery current and hence improving the battery cycle life. The paper also includes the hardware results based on a laboratory prototype of the proposed EV system validating the performance of the proposed control strategies.