Design, analysis, and control of switched supercapacitor banks for e-transportation electric energy storage systems

Abstract

The hybridization of supercapacitors (SCs) with batteries in electric vehicles (EVs) improves the battery life, acceleration, and driving range. However, the efficiency of the power interface that unites the batteries and SCs are affected due to wide voltage variations at the SC bank terminals. Moreover, the SC bank offers low storage that restricts them from serving a continuous series of transient load demands on a single charge. A novel bank switching architecture for SCs is introduced to enhance the power delivery duration and energy utilization of SCs with controlled terminal voltage variations. A simple transition control strategy is proposed to effectively switch the SCs. The efficacy of the proposed work is validated using simulations and experimental studies on a laboratory-developed prototype. Furthermore, the suitability of the proposed SC bank in HESS for an EV is verified with four standard driving cycles, in terms of voltage variations, and depth of discharge.