The New Adaptive Under Frequency Load Shedding Technique in an Automated Distribution Network Considering Demand Response Programs

摘要

Under Frequency Load Shedding (UFLS) is an important protection scheme to maintain the frequency of a Distribution Network (DN) consisting of Distributed Generations (DGs) exposed to power deficit. The different location and amount of load curtailments based on different parameters are acquired from the available literature. In this paper, an optimal adaptive UFLS method with the advent of two main modules has been proposed. The proposed method provides a revised Rate of Change of Load (ROCOFL) index related to bus voltage and load power consumption (ROCOFLpv). Using a wide area measurement system, Demand Response (DR) technology aimed at shedding fewer loads is emerging against a background of the smart grid. In addition, smart appliances can provide a real-time data packet in which frequency, the rate of change of frequency, voltage magnitude and breaker status are measured. The proposed method is implemented in five different load schemes considering DR programs. Comparative analyses are illustrated in this paper to assert the efficiency of implementing DR programs in which cost function and amounts of shedding loads are decreased. The results demonstrate that DR programs cannot be used for a big power unbalance in an islanded micro grid. The unintentional delay time imposed by DR and the small inertia existing in an islanded distribution network restrict the use of DR programs.