Supercapacitor-based optimum switched reluctance drive for advanced electric vehicles

Hybrid energy source by using optimum combination of supercapacitor and battery in parallel, is incorporated into switched reluctance motor (SRM) drive for an advanced electric vehicle. SRM controller is optimized to maximize the system efficiency at all operation states including motor operation and regenerative braking, and the hybrid energy source affords an opportunity to design the battery bank that is optimized for the specific energy and cycle life with little attention being paid to the specific power. The battery current is decreased and stabilized because supercapacitor bank supplies a large burst of current, and the size and weight of battery reduce, which result in the potential increase in the battery life and a decrease in the cost with assistance of supercapacitors of longer lifetime. The whole system including SRM, power converter, SRM controller, bi-directional DC/DC converter with controller, battery bank, electrolytic capacitor, and supercapacitor bank is modeled. The proposed system with hybrid power source is compared with that with the battery-only by simulating their performance in all operating situation such as acceleration, deceleration, and motor etc. Simulation results verify the proposed drive with supercapacitors, and show that the optimized SRM drive for electric vehicle is achieved.