An Anti-islanding Control System for Distributed Generation Plants with Synchronous Machines

By L Piegari et al

The paper deals with the islanding phenomenon in distributed generation plants. The islanding occurs when, for intentional or unintentional events, one or more generation units are disconnected from the main grid and operate as islanded units. The islanding operation mode is not desirable because introduces unsafe conditions of the system, makes the system unstable and reduces the power quality. In the paper an anti-islanding control system, applied to micro-grids with synchronous machines, is proposed. The control detects the islanding by checking the generator speed variation and acts to re-connect the machines to the grid without problems. The mathematical model of the micro-grid is set up and described, the control system is validated by means of numerical simulations.