Battery-Ultracapacitor Hybrid Energy Storage System to Increase Battery Life Under Pulse Loads

This work presents a battery-ultracapacitor hybrid energy storage system (HESS) for pulsed loads (PL) in which ultracapacitors (UCs) run the pulse portion of load while battery powers constant part load. Energy stored UC depends upon square its voltage that’s why an active parallel topology with two bidirectional converters (BDC) is employed here that assigns separate BDC to control between upper and lower limit as per-requisite. The other converter connected DC-link provide distinct battery. A MATLAB/Simulink model developed minimize factors affecting life such capacity rate (C-rate), depth discharge (DoD), temperature rise due PL by controlling operating modes BDCs state charge (SoC) are variables. output across maintained through feedback control. detailed comparative analysis, among battery-alone, UC-alone, battery-UC performed signifies proposed 55% cost than counterparts. analysis shows HESS reduces 50% lead-acid battery, otherwise necessary withstand pulsating loads. Moreover, performance also tested electric vehicle (EV) hybridizing high-voltage lithium-ion pack bank confirms suitability EV applications.