On-line health monitoring of PV plants

Tracing current vs. voltage curve is an important part of the documentation of a Photovoltaic (PV) system to comply to the IEC 62446 standard. In order to get the high accuracy, the PV array would be subjected to an unspecified and large number of voltage perturbations often using specialized measuring instruments. In this paper, we explain how to minimize the tracing-time by performing a pre-defined and small number of perturbations without using specialized equipment yet still document the PV working condition. Instead, the existing PV maximum power point tracker (MPPT) is used to perform the test. The proposed approach could also be useful to some PV techniques like Dynamic PV reconfiguration, where a minimal information about the quantity of healthy and faulty modules working condition is desired to determine internal solar array module connections.