Model based distributed MPPT using current equalization for contoured flexible PV strings

Abstract

A string of flexible PV modules (FPVs) mounted on a contoured surface leads to mismatches between the PV modules due to their different orientation. Due to this, each module operates at different conditions of radiation and temperature resulting in increased power losses. To extract maximum power from each PV module under these conditions, it is necessary to make each individual module to operate at maximum power point (MPP). This is achieved using a current equalization method by operating each PV module at its maximum power point voltage. The determination of the MPP voltage of the FPV module is a key factor to implement the current equalization scheme efficiently. An empirical model for FPV module based on detailed analysis of experimental results was proposed earlier to extract maximum power. In the present work, a current equalization scheme is implemented by using this model for obtaining the MPP voltage from a PV module in a string which is mounted on a contoured surface. The model based current equalization scheme gives an approximate MPP. However, this scheme is easy to implement. Analysis and simulation results of the model based current equalization scheme are given in the paper.