Digital twins based fault diagnosis and reconfiguration of high gain topology for utility level PV system

Abstract

ABSTRACT This paper proposes a reliable fault diagnosis and reconfiguration strategy based on digital twins that is implemented in an enhanced Z-source-based high-gain dc-dc converter for interfacing utility-level photovoltaic (PV) systems. One of the major failure source in a PV system, however, is the interfacing of DC-DC converters. A switch fault detection technique (FDT) is essential to ensure the reliable operation of these converters, as semiconductor switches are among the most important components. However, the literature does not adequately address switch fault detection and reconfiguration strategies in high-gain DC-DC converters. Open-circuit and short-circuit faults in the MOSFET switch can be detected with a simple FDT that measures diode voltage. The presented fault diagnosis scheme relies solely on diode voltage as its signature for detection. FDT and reconfiguration logic isolate switch faults and reconfigure converters to achieve the desired output voltage without introducing any additional components. A simple logic circuit processes the diode voltage and gate driver signal to generate switch and diode fault indicators (FI). The Z-source-based converter’s FDT makes it fault-tolerant. Experimental validation confirms the excellent performance of the proposed fault-tolerant high-gain converter under healthy and faulty conditions.