Frequency control in microgrids using electric springs

The electric spring (ES) is designed to realize the change of the power consumption following the power supply, which can effectively alleviate the active power shortage in the system. It provides a new idea to solve the problem of frequency fluctuation caused by wind turbine connected to the power grid. According to the analysis of ES participating in frequency control, this paper proposes the ES strategy based on phase and amplitude control. Based on this strategy, the controller of ES is designed, which can make ES work in the capacitive mode and inductive mode, respectively, according to different frequency fluctuations. Finally, two cases of single power supply system and microgrid are simulated in MATLAB/Simulink to investigate the effect of ES participating in frequency regulation. The simulation results show the feasibility and effectiveness of the proposed model and strategy.