Impact of islanding and resynchronization on distribution systems

This paper describes the impact of islanding on the distribution systems. According to IEEE Std. 1547-2003, intentional islanding is a topic under consideration and many utilities do not allow islanding due to the risk of system failure and safety hazards. However, planned islanding if it is used prudently can enhance reliability by serving critical loads when the main grid has been disconnected. Dynamic simulations are performed on a radial and a meshed distribution system and the results are presented in this paper. The simulations show the effect of non compliance of the IEEE Std. 1547-2003 and out of phase resynchronization of the DGs to the grid. The simulations are performed using the EMTP-RV package. The results also show that an islanded mode can be sustained by using load shedding techniques.