Impedance Spectroscopy as On-Field Monitoring Technique for PV Modules

Detecting degradation phenomena on photovoltaic (PV) module working under real operating conditions is challenging. In recent years, impedance spectroscopy (IS) has been explored as a promising technique for the detection of faults in PV systems. The adoption of IS in on-field monitoring and diagnostic tools requires a reliable and straightforward ac model of the device under test. To this aim, the authors analyze the frequency response of standard crystalline silicon (c-Si) based PV module working under real operating conditions by means of technology computer aided design (TCAD) simulations in Sentaurus environment. The simulated experiments emulate the behavior of the PV module both in healthy and faulted conditions. Finally, the considerations arising from this analysis help to define practical guidelines as well as highlighting limitations of the adopted technique.