A novel method for parameter identification and performance estimation of PV module under varying operating conditions

Abstract

In this paper, a novel and adaptive method is proposed for parameter identification and performance estimation of a photovoltaic (PV) module under varying operating conditions. By comprehensively considering the irradiance and temperature dependence of physical parameters in a single-diode model, a set of new transforming equations is proposed to model and calculate parameters under varying operating conditions. This set is developed to calculate physical parameters without setting any reference condition, thereby eliminating the effect of such reference condition on the accuracy of parameter identification and performance estimation. The coefficients of the transforming equations are calculated by fitting experimental I–V data under a wide range of irradiance and temperature conditions through optimization technology. To reduce the complexity of multi-parameter optimization, three operating points (short circuit, open circuit, and maximum power) provided by the manufacturers are used to reduce the dimensions of the search space. Moreover, a new objective function is proposed for parameter optimization by considering five key operating points for each I–V curve. This improves the accuracy and reduces the computational cost. In contrast with existing methods using parameters under a reference condition, the proposed method estimates the output performance of the PV module under different operating conditions with high accuracy and efficiency. This was validated by experimental data for six different types of PV modules under wide operating conditions.