Enhancement of microgrid frequency control subsequent to islanding process using flywheel energy storage system

Recently connection of some Distributed generation and load has created Microgrids (MGs). This MG can operate in grid connected mode or disconnects from main grid. Maintaining stability of MG When it is disconnected from main grid, is an important problem. Frequency stability is one of aspects of stability. Using of energy storage with appropriate control strategy can be effective in this subject. In this paper A flywheel energy storage system (FESS) in detailed is described and is used for frequency control in islanding mode. Two control strategies for DGs inverters are stated and suitable method for each DG and FESS is selected. Simulation is carried by MATLAB/Simulink. Two case studies are examined. In two cases, FESS effect on frequency in islanding process is discussed. Results of simulation verify appropriate operation of FESS and confirm effectiveness of this application.