Optimum sizing and optimum energy management of a hybrid energy storage system for lithium battery life improvement

• Published in: Journal of power sources 2013-12, Vol.244, p.2-10
• Main Authors: Masih-Tehrani, Masoud, Ha'iri-Yazdi, Mohammad-Reza, Esfahanian, Vahid, Safaei, Ali
• Format: Article
• Language: English
• Subjects: Applied sciences; Direct energy conversion and energy accumulation; Electric batteries; Electric power generation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Energy storage; Exact sciences and technology; Hybrid energy storage system; Hybrid systems; Hybrid vehicles; Lithium batteries; Lithium iron phosphate battery life; Optimization; Optimum power distribution; Optimum sizing; Series hybrid electric bus; Sizing
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2013.04.154

In this paper‎, ‎a formulation is developed for sizing of a Hybrid Energy Storage System (HESS) in different applications‎. ‎Here‎, ‎the HESS is a combination of Lithium battery and Ultra-Capacitor (UC)‎, ‎which is useful for many high energy and high power applications such as Hybrid Electric Vehicles (HEVs) and renewable energy‎. ‎The sizing formulas are based on initial cost and 10-years battery replacement cost which is arranged as an optimization problem‎. ‎For battery replacement cost‎, ‎the Lithium battery capacity depletion formulas are studied for a LiFePO4 battery‎. ‎As a case study‎, ‎application of HESS in a Series Hybrid Electric Bus (SHEB) is considered‎. ‎The results show by the addition of UC‎, ‎the Lithium battery life is improved significantly‎. ‎Furthermore‎, ‎the optimum sizing of the HESS is dependent to the SHEB driving cycle‎. ‎Therefore‎, ‎considering the power profile of the HESS in its sizing process may reduce HESS cost‎. ‎This effect is studied in three different cycles of the SHEB‎. ‎In addition‎, ‎the formulation is applied to cycle-based optimization of the Power Distribution Control Strategy (PDCS) of the HESS by dynamic programming‎. ‎The results show the optimum PDCS has better LiFePO4 battery life in comparison with the conventional PDCS‎. •A formulation is defined for battery and ultracapacitor combination optimum sizing.•ESS hybridization causes to reduce ESS cost and fuel consumption, simultaneously.•The HESS optimum sizing shows strong dependency to the vehicle driving cycle.•The optimum (dynamic programming) power distribution of HESS increases battery life.•The method is useful for high energy and power application (HEVs, renewable energy).