Short-time voltage variance detection of micro-grid with direct-drive wind power generation

Simulation model of micro-grid including a direct-drive wind power generation, two sets of power-controlled distributed generations (DGs) and a three-phase fault module was investigated in Matlab/simulink. Based on the constructed model, the operating process switched from island mode to grid-connected mode was simulated and the voltage variance signal was detected with Daubechies(Db) wavelet. The simulation results show that the singularity of voltage variance was quickly and accurately detected with db wavelet. The fast and accurate detection of short-circuited fault signal is helpful to improve power quality of micro-grid.