Power Electronic Implementation of Electrochemical Impedance Spectroscopy on Photovoltaic Modules

Electrochemical impedance spectroscopy (EIS) is a non-destructive characterization technique carried out using injected signal analysis. This work investigates the implementation of EIS on photovoltaic (PV) modules using single sinusoid and optimized broadband signals applied via power electronic converter. The procedure applied in this work is carried out to explore rapid online condition monitoring of PV modules using associated power electronic systems. The perturbation signals applied in this work were superimposed using pulse width modulation in a dc-dc boost converter. The injected and output signals were analyzed to determine the impedance of the PV module at various frequencies under normally illuminated and partially shaded conditions. The results obtained were compared to the use of a standard frequency response analyzer (FRA). The results show significant agreement for both the power electronics implementation and FRA tests.