An innovative control strategy for a hybrid energy storage system (HESS)

Abstract

Abstract-Electric Vehicles (EVs) adopting both batteries and supercapacitors have attracted a significant amount of attention in research communities due to its unique power sharing capabilities. A Hybrid Energy Storage System (HESS) can effectively reduce power stress that would otherwise be applied to batteries alone, and whose weight and size is still a common concern when competing against conventional ICEpowered cars. In this paper, a high-level control strategy is developed to adaptively split the load between two sources for an electric vehicle adopting HESS under real-life load fluctuations. A converter -Supercapacitor Pack (SP) coupled HESS upon which such an algorithm is deployed on, is proposed to divert excess power that would otherwise overdraw from or damage the Battery Pack (BP) into the SP via a smart Power Converter (PC) which is located in between in order to regulate both behaviors. Such a power split strategy (PSS) is designed in such a way to track real-time load profiles and determines one important variable -the cut-off frequency. As a consequence, relatively higher frequency portion of the load power gets channeled to the SP and the remaining lessvarying power demand is sent to the BP based on the fundamental energy balancing equation. A simplified HESS model is first developed. The power split algorithm is coded in Matlab and then applied to this HESS model. Finally, the overall system is tested comprehensively over 4 EPA driving cycles. Simulation results prove its effectiveness in coping with even the harshest driving scenarios in real life.

Optimization Method for the Integration of Hybrid Energy Storage Systems in Industrial Applications

“…Once the contracted capacity is settled for each period, the contracted capacity charge (CCC) is calculated using (16), where P f i is the contracted capacity in period i expressed in kW and C pi is its annual price in period i. The energy charge (EC) is computed following (17), where E i is the energy consumed in the period i (expressed in kWh) and C ei is the price of the energy in that period i.…”

“…The proposed optimization method allocates the power by using digital filtering techniques over the consumption profiles. [17]. The HESS operation will be targeted for peak shaving during the tariff high cost periods.…”