Optimization and Analysis of Photovoltaic Systems under Uniform and Partial Shading Conditions

Abstract

This thesis presents a new approach for converting the implicit current-voltage (I-V) expression of a photovoltaic (PV) module into an explicit expression of current as a function of voltage. The maximum power point (MPP) of a double diode model (DDM) PV module is estimated directly from the explicit I-V expression of a module under different environmental conditions (DECs). The extension of use of explicit I-V expression to estimate the MPP of a DDM PV module under different shading conditions is also carried out. Since the explicit I-V expression is used for the estimation of the MPP of a DDM PV module under both uniform and non-uniform irradiance conditions, the proposed method is simple, accurate, and efficient. A comparison of the MPP of a DDM PV module, as extracted using the proposed method, with that obtained from different existing methods under various irradiance conditions, is presented. The MPP of the DDM PV array at non-STC (Standard Test Condition), as determined by the proposed method, is verified through experimental measurements and MATLAB simulations. The results show that the estimation of the MPP of a DDM PV module using the proposed method is more accurate and computationally efficient. The explicit I-V expression of a module, used for estimating the MPP, will be useful to PV professionals.