Frequency regulation in Islanded microgrid using demand response

Introducing more Distributed Generation (DG) into power grid infrastructure drives more attention to understand how large scale DG affects grid operation. Islanding is an important concern in this area. Islanding refers to the condition that DGs within a microgrid continue energizing while the microgrid has been disconnected from the main grid. Considering the adverse effects of Islanding, it should be detected and managed in a proper way. After Islanding has been detected, even though the first option is tripping all DG units and shutting down the system, the microgrid has this option to work as a standalone system. For this, the microgrid frequency regulation is a must. This paper comprises two parts. First proposing an islanding detection method based on communication between the microgrid and the main grid. In the second part, after detectiong the islanding using the first part, it presents an effective implementation Demand Response (DR) to regulate the frequency in islanded microgrid as an Ancillary Service (AS) considering the transient constraints of frequency in inverter-based generations.