Optimization Strategy for Under Frequency Load Shedding in Isolated Microgrids Under Extreme Operating Conditions

When a fault occurs in the distribution network, the microgrid will form unplanned islanding conditions, resulting in load shortages and frequency drops. A under frequency load shedding strategy for islanded microgrids under extreme operating conditions is proposed to address this issue. Firstly, based on the importance of load, establish a microgrid node load classification model. Secondly, considering the frequency characteristics of loads and the economic losses of load shedding, a under frequency load shedding strategy for classified loads in isolated microgrids is formulated to restore system frequency, and optimization algorithms are used to obtain the optimal execution action. The final simulation results through numerical examples show that the proposed algorithm can quickly reduce the load plan and restore the frequency, verifying the feasibility and effectiveness of the proposed unplanned islanding under frequency load reduction strategy for microgrids.