Novel Parametric Tolerance based Fault Identification Technique for PV System

Small parametric tolerances (PT) occur in PV modules due to manufacturing. PV system tends to show differences in characteristics due to these parametric tolerances. The objective of this paper is to distinguish healthy and faulty conditions of a PV system utilizing the performance deviation due to PT and identify the nature and location of fault based on the known PT data. A PV system, with specified PT, is modeled and simulated for faults like module-ground and module-module. Healthy and faulty conditions are shown to be easily distinguished with the knowledge of PT. Though PT leads to 'fault-like' conditions, it also enables exact determination of fault location with the help of accurate current sensors. Results are validated experimentally on a real PV system for various fault scenarios. As the complexity of the PV system increases, the proposed technique is more suitable for accurate fault identification and it requires only string level current sensors.