A new modelling approach for a Cuk converter for on-field diagnostics of PV modules

Field diagnostics is an essential tool for ensuring the energy yield of photovoltaic (PV) systems and securing the return on investment. Impedance Spectroscopy (IS) has been the focus of significant research and shows great promise in becoming a standard diagnostic method for PV systems. In this work, we present a specially designed and dimensioned CUK converter for conducting IS analysis on individual solar panels installed in PV plants. The design and sizing of the converter are performed using specific modeling techniques. Notably, it is proposed an accurate discrete-time model, which reduces the simulation times and facilitates a comprehensive understanding of the system's operation, paving the way for the development of discrete-time control for microcontroller implementation.