Dynamic power optimization of contoured flexible PV array under Non-Uniform Illumination conditions

Abstract

Lightweight, flexible PV (FPV) modules are suitable for BIPV and stand-alone applications where contoured layouts are required and system weight is a constraint. This report focuses on optimization of a contoured FPV array which operates under Non Uniform Illumination (NUI) conditions. NUI conditions can occur at low solar angle for contoured layouts and also due to unexpected partial shading events. The output Power Voltage (P-V) characteristics under contouring and partial shading demonstrate severe oscillatory behavior around the maximum power region, which results in inefficient implementation of established tracking algorithms that seek to detect a dominant global maxima. An algorithm for MPP tracking has been proposed that takes into account both static and dynamic parameters. An integrated test system has been developed which can accurately monitor solar irradiance (range 100-1000 Watts/m 2 ) and solar angle and load dependent instantaneous output voltage and current. The system has been designed for maximum current and voltage rating of 3A and 25V respectively. While an output power penalty results due to contouring, our results show a very small energy differential up to a maximum array contour value of 10°. This analysis may lead to development of novel, flexible PV array based designs.