A fast parameterized model for predicting PV system performance under partial shade conditions

Accurately modeling the performance of partially shaded photovoltaic systems is well-known to be a difficult problem. Power loss is not only nonlinear with shade coverage, but also has a strong dependence on system configuration and location of the shade on a system. This paper presents a parameterized shade loss model (called the “Fast Shade Model” or FSM) that allows for the calculation of system-level power loss based on three input parameters. This model was developed through the statistical analysis of hundreds of thousands of shade scenarios modeled with a cell-level, 2-diode model. Model validation was performed using real systems under shaded conditions.