SSTPI-IM Reconfiguration and Diagnostic under OCF Appearance Used in PV System

Abstract

In order to the increase of the conventional inverter reliability used in PV systems, many diagnostic methods have been investigated to these converters reliability. These diagnostic methods are applied in order to detect and identify the IGBT's OCF. In this paper, the proposed diagnostic method is based on the normalized currents and current's slope information's. Due to the continuity importance in PV systems after the appearance of IGBT's OCF, this paper presents a SSTPI-IM diagnostic method and reconfiguration strategy controlled by the direct RFOC used in PV system. The fault reconfiguration is based on the change of the SSTPI topology to the FSTPI topology using relays and a redundant leg. The redundant leg is only used in the cases of IGBT’s fault’s appearance in more than one SSTPI leg. The effectiveness and performance of the proposed SSTPI-IM diagnostic method and reconfiguration strategy in terms of systems continuity and fast detection and reconfiguration are validated by the simulation results.