Comments and Overviews on the Islanding Methods of Large Interconnected Power Grid

Grid islanding is the last defense of the security and stability of power grid. It can inhibit the spreading of serious disturbance in power system, such as oscillatory and instability between asynchronous generator groups, and create self-balancing environment for every isolated island. The successful grid islanding control can save many power loads, and avoid large-scale blackout, such as the blackout of USA and Canada in 2003, the Brazil blackout in 2009 and the India blackout in 2012. So the grid islanding control would contribute to reduce the losses of national economy, and maintain the social stability and safety. On the contrary, an unsuccessful grid islanding control would suffer the power system and the society. In the paper, the development of the grid islanding control had been overviewed from the aspects of engineering application and theoretical research. The theoretical research of grid islanding control and its problems were summarized, including the splitting surface definition methods and splitting timing judgment methods. Suggestions for these issues were proposed in the paper.