A high performance power supply for an Electric Vehicle with solar PV, battery and ultracapacitor support for extended range and enhanced dynamic response

Abstract

This paper proposes a highly reliable, extended range power supply for an Electric Vehicle (EV). The power supply consists of solar PV source and is supported by dual storage comprising battery and Ultracapacitor (UC). Battery is the main source of power, which is supported by the UC during the transient phase such as starting and braking (regeneration) and solar PV during the steady- state operation. The net effect of this arrangement is enhanced travel range, reduced battery size, enhanced battery life and excellent dynamic response during the dynamic phase. Improved dynamic performance results in smooth ride, optimal energy utilization and optimal sizing of energy sources. All the sources are interfaced with the common DC link through dedicated DC-DC converters. Battery and UC converters provide controllable bi-directional power flow capability. Solar PV source is operated with Maximum Power Point Tracking (MPPT). The paper describes control strategies for all the converters under various operating modes to ensure stability and fuel efficiency of the EV. The control strategy includes the inner current and outer voltage correcting loops for the storage interfaces to render fast dynamic response. Detailed modeling and design is provided for compensators used with storage and source interfaces. To validate the analytically developed controllers, the complete system is simulated and the steady state and dynamic performances are evaluated. Experimental verification of representative results are provided with a scaled down laboratory prototype.