Power management strategy for hybrid energy storage system in hybrid electric vehicles

Abstract

Energy Storage System (ESS) is an essential component in the Electric Vehicles (EVs) because of its high power and high energy density. In Hybrid Electric Vehicles (HEVs), the Hybrid ESS (HESS) is introduced to resolve the problem occurs due to single energy storage system. This HESS is utilized for achieving high power and energy simultaneously. In this paper, the HESS is used in HEVs to improve energy management over the vehicles. The HESS is the combination of battery and Ultra-Capacitor (UC). Here the Nickel-Metal Hydride (NiMH) battery is used as a primary energy source and UC is used as a secondary energy source. The energy management over the HEVs made by an effective Artificial Neural Network (ANN) based controller which is utilized for handling the charging and discharging operation of the ultra-capacitor. The operating mode of UC using ANN is mainly based on the State of Charge (SOC) from the battery at each iteration. The UC is on, when the SOC of the battery is less than 60%, it shows that the battery does not have the capacity to achieve the load requirement of Permanent Magnet Synchronous Motor (PMSM). The performance of the proposed system analysed in terms of speed, torque and current. Then it evaluated by using the system with ANN and without ANN. The motor speed and vehicle speed of the HEV with ANN at 70 Sec improved 8% and 9.38%, respectively compared to the HEV without ANN.