Parameter Identification of a PV Source Dynamic Model with Piecewise-Linear Circuit-Based Approach

This paper deals with a method for the parameter identification of an improved dynamic model of a photovoltaic (PV) source, which encompasses a capacitor and an inductor. The method is based on piecewise-linear (PWL) circuit approximation and step load responses. Considering the PV I-V characteristic as a PWL function, if a transient occurs in a linear region, the PV source can be approximated according to Thévenin's theorem. The cases referred to either capacitive or inductive dominant time constant are explained. The identification of the circuit parameters by least squares regression (LSR) applied to experimental data is discussed and finally a case study is presented.