STFT-based electric vehicle charging access to grid voltage sag disturbance detection

Large-scale electric vehicle charging access to the power grid in the new energy industry has become the norm, the study of its perturbation with the grid power quality is important for the stable operation of the grid, grid power quality disturbance detection is the primary solution to the problem. For the electric vehicle charging access to the grid to generate a short duration of the voltage sag disturbance phenomenon, this paper adopts the short-time Fourier transform (STFT) as a time-frequency signal analysis tool, the establishment of the grid signal affected by the voltage sag disturbance STFT analysis model, to achieve the accurate detection of the perturbance. The disturbance signals are simulated by Matlab, and the spectrograms and amplitude diagrams of the disturbed signals are analyzed under the short-time Fourier transform simulation. The simulation results show that the STFT transform, which selects the appropriate window function, can accurately detect the perturbation signal and is a feasible and effective detection method.