The numerical computation of lumped parameter values using the multi-dimensional Newton-Raphson method for the characterisation of a multi-junction CPV module using the five-parameter approach

The new approach was validated experimentally by means of both qualitative and quantitative assessment. Results revealed that the proposed method was able to accurately model this device type and when compared to several alternative methods, yield the lowest average root mean square error (RMSE) with a 7-55% improvement offered over the alternative methods investigated. The proposed method will be useful to engineers and scientists who wish to characterise the performance of multi-junction photovoltaic devices using the single-diode, five-parameter model and require a method to extract the values of their characterisation parameters. A limitation with this approach is the computational effort required to solve the system of non-linear residual equations and the need for good initial estimates of the lumped parameters to initiate the search.