A reconfigurable PV array scheme integrated into an electric vehicle

Abstract

This paper outlines an adaptive photovoltaic (PV) array topology and control scheme which has been implemented on a small battery electric vehicle. An array of PV cells is reconfigured in real time via a switching matrix to maintain a close proximity between the array’s maximum power point and vehicle DC bus voltage. Keeping the maximum power point close to the vehicle battery terminal voltage improves the performance of the DC-DC converter. Under some operating conditions, the DC-DC converter can be bypassed altogether. A control scheme involving a physical model of the DC-DC converter is used to determine real time efficiency of the power electronics and maximum power point tracking algorithm, and coordinates the operation of the MOSFET based PV cell switching array, DC-DC Buck Converter and DC-DC converter bypass MOSFET. Numerical results are presented demonstrating an average efficiency improvement of 12% over a traditional fixed scheme, over a range of vehicle battery terminal voltages and solar irradiation values.