Diagnosis And Mitigation of Voltage and Current Sensors Malfunctioning in a Grid Connected PV System

Abstract

A grid-connected photovoltaic (PV) system cannot function effectively without sensors that accurately measure the voltage, current, and AC currents flowing between the VSC and grid. As the impact of erroneous measurements propagates through the controllers in a PV system, they can cause significant disruptions to the system's operation due to malfunctioning of the aforementioned sensors. PV system sensor failures are referred to as sensor faults in this paper. A method for diagnosing and correcting PV system sensor faults is presented in this paper. The sliding mode observer (SMO)-based fault detection and identification theory, which is capable of accurately estimating faults from sensor measurements, serves as the foundation for the fault diagnosis strategy. In the proposed method, the fault mitigation technique is used to correct the sensor measurements using estimated faults. In order to guarantee the PV system's fault-tolerant operation, the controllers use rectified sensor measurements rather than potentially incorrect sensor measurements. Extensive simulation and experimental research has shown that the proposed method works