Hybrid energy storage system design: Outlier performance improvement of x-EV battery pack

Abstract

With the technological advancement in electrical mobility the perception of the customer is also inclining towards the electric vehicles. But still come customer are doubtful about the EV performance as compared to conventional ICE vehicles. This anxiety is fair as battery which is the primary component of xEVs still needs to grow further and needs to catch up with the performance standards of an internal combustion engine. Batteries can perform well as compared to IC engines in a fixed SoC range only but beyond this range the performance of the battery decreases. The work presented in this article is the effort to make battery performance inch further towards the ICE vehicle. This article demonstrates energy management strategy of a multi-chemistry battery pack to improve the vehicle performance in outlier conditions of the operational energy band and match the performance with IC engine vehicles. To demonstrate this a multi chemistry hybrid energy storage system is proposed which combines two distinct battery chemistries LFP end NMC in a single battery pack. These two different battery packs will be utilized to meet the power target and the energy target. To utilize the advancement of HESS as compared to SESS the energy management strategies are proposed. The results shows that the proposed solution can overcome the current performance limitation of the battery pack in terms of consistent power delivery over the entire operating range of vehicle during discharging and regeneration. With the proposed performance enhancement, the user may not feel the drop in acceleration towards the end of discharge the proposed strategy will also enhance the range and cycle life of the vehicle and the battery respectively.