Under Frequency Load shedding Algorithm in Smart Islanded Networks Using Loads Frequency Index

This paper presents an optimal method of frequency load shedding (UFLS) based on the rate of change of frequency of load (ROCOFL) in islanded distribution networks (DN). The proposed method minimizes the average amount of penalties paid by the independent operator of the network by utilizing the relevant cost function. The function of islanded distribution network occurs after an error in the sub-transmission network and separation from the upstream network, in an emergency condition, is one of the most important facts that has been recently addressed. The use of installed intelligent equipment to measure and send information, related to power, frequency, frequency changes, voltage range, and condition of generator switches makes it possible to provide an appropriate protection for the islanded networks. The under frequency load shedding is used to improve the network frequency due to the imbalance in the network. In this paper, it is tried to use the two proposed control modules to eliminate the optimal load with the consideration of the minimum penalty. The method presented in this paper is evaluated in the sample network of 14-bus Danish distribution network.