Parameter Estimation for Single Diode Models of Photovoltaic Modules

Many popular models for photovoltaic system performance employ a single diode model to compute the I-V curve for a module or string of modules at given irradiance and temperature conditions. A single diode model requires a number of parameters to be estimated from measured I-V curves. Many available parameter estimation methods use only short circuit, open circuit and maximum power points for a single I-V curve at standard test conditions together with temperature coefficients determined separately for individual cells. In contrast, module testing frequently records I-V curves over a wide range of irradiance and temperature conditions which, when available, should also be used to parameterize the performance model. We present a parameter estimation method that makes use of a full range of available I-V curves. We verify the accuracy of the method by recovering known parameter values from simulated I-V curves. We validate the method by estimating model parameters for a module using outdoor test data and predicting the outdoor performance of the module.