Comparison of mathematical models of photo-voltaic (PV) module and effect of various parameters on its performance

This paper presents a comparison of different electrical equivalent mathematical models for a PV cell/module/array based on Shockley diode equation. The presented different models include single diode model and double diode models. These models accept solar irradiance and temperature as input parameters and yield the I-V & P-V output characteristics. A control algorithm called MPPT (maximum power point tracking) algorithm is typically integrated with PV systems in order to extract maximum possible power from it. Thus, there is a need to select an efficient and simple PV model which can be used to realize efficient MPPT algorithm. In addition to this, other parameter should also be taken into account for finding the best model for use in the simulation. In this paper, the comparison of different models are performed on the basis of the MPP tracking and values of various parameters like peak current, peak voltage, open circuit voltage and short circuit current value achieved from the output I-V and P-V characteristics and their resemblance with manufacturer specified specifications. Using this analysis, the best (efficient as well as simple) model that can be used for simulation purpose is selected. Such a model is useful for professionals who require PV simulators for their design. Additionally, the paper also illustrates the effect of various parameters like diode ideality factor, series resistance, input sun radiation and cell temperature on single diode model performance. Model evaluation is performed using a VIKRAM ELV-40 of 37W PV module. All mathematical models presented here are programmed using script file in the MATLAB environment.