Fault Detection and Diagnosis in a PV Grid-Connected T-Type Three Level Inverter

In grid-connected photovoltaic systems (PV) the inverter is a fundamental component. In fact, a fault in a switch of this power converter could result in an important system malfunction. Thus, fault detection and diagnosis of this fault type is fundamental to overcome this problem. This paper proposes a fault detection diagnosis for the T-type three level inverter. This inverter presents characteristics such as output voltage multilevel and good capability to work in fault tolerant mode. The proposed fault diagnosis method is based on the mass center of the voltage pattern. It is characterized by low computational requirements and not dependent of the load. Simulation results show the characteristics of the proposed method.