Effective Approximation of the Photovoltaic Characteristic Curves using a Double-shaped Superellipse

Photovoltaic model (PVM) presents an easy and reliable way to evaluate both the static and dynamic behaviors of photovoltaic systems. Due to the implicitness of the basic I-V characteristic equations, a high number of unknown parameters, and the mathematical complexities of these conventional models, the effective performance analysis of these systems is still cumbersome. In this paper, a novel empirical model based on unique similarities between the geometric shapes of a superellipse and the graphical characteristics of the I-V curve is presented. As such, a step-by-step procedure describing the full-range approximation of the PV characteristic curves and parameter extraction process is illustrated. Regardless of the PV panel cell type, simulation results show that the proposed model maintains the 1% absolute error within the vicinity of the maximum power point.