Securing Passive Islanding Detection and Enabling Stable Islanding with Q/f -Droop Control of DG Unit

摘要

In Active management of distribution networks and different controllable resources will play a key role in future Smart Grids. This paper proposes that centralized active network management functionalities at MV level could also include an algorithm which in real-time confirms reliable islanding detection with local measurements based passive method. The proposed algorithm continuously ensures that there is such reactive power unbalance, so that the operation point remains constantly outside the non-detection zone of the used passive islanding detection method. The effect of recent grid code requirements, like P/f-droop control of DG units, on the proposed scheme has been also considered. In addition, usage of additional Q/f-droop on MV level DG unit in order to enable stable islanding or to even further ensure reliable islanding detection and disconnection of DG units has been studied.