Fault Detection Strategy for Grid-Tie Three-Phase Photovoltaic Inverter

This work presents a fault detection study for grid-tied three-phase inverters. One of the existing concerns with grid-connected PV inverters is fault detection and protection coordination. Since PV systems require inverters to connect to the grid, it is pertinent to study the behavior of this system component to accurately model fault scenarios. When a fault occurs, the PV inverter must detect the disturbance and react quickly to avoid damage to it and other components. In this paper, a control strategy is proposed to detect faults in PV inverters without the use of additional communication or hardware resources. This strategy makes use of the current between any two nodes on the distribution network, and then compares their values, which must be almost the same. A tolerance level is targeted and any difference between this tolerance triggers a start-detection mechanism in the PV inverter. The proposed model was carried out in MATLAB/Simulink to ascertain its efficiency and practical implementation.