An implementation of an enhanced DG primary control equipped with fault detection scheme

This paper proposes an enhanced primary control unit of the distributed generator inside the microgrid when the DG is grid-connected and when operated autonomously. The control methods needed for the DG inverter when operated in grid-connected mode and autonomous operation mode have been investigated. The rotating reference frame employed for the control of the DG has been clarified to investigate how the active and reactive power of the DG are delivered to the main grid. When the DG suffers from local disturbance conditions, it should be disconnected from the main grid and switched off or its control unit is changed to voltage-frequency mode. Therefore, a fault detection scheme has been implemented to monitor the voltage and frequency of the DG bus. Hence, the performance of the proposed work has been validated under steady-state and short circuit conditions where the DG inverter is operated in grid-connected mode, switch-off mode, and autonomous mode.