The Analysis of Short Duration Power Quality Disturbances Using Short Time Fourier Transform

The present power system have been charac-terized by high dynamics due to advances such as the accessorial loads, switching power supply equipment and enhancement of power system regulations. The power quality (PQ) analysis was earlier performed using Fourier Transform (FT) where parameters such as time-amplitude variations and frequency-amplitude variations were used. However, these parameters focus on the stationary power quality disturbances(PQDs) and cannot capture non-stationary or short duration PQ disturbances. Modern power systems need a broader viewpoint based on the amplitude, duration, and frequency of interruptions. In this paper, Short Time Fourier Transform(STFT) is proposed for identification of short duration PQDs which include voltage sags, swells, interruptions, transient oscillations and harmonic. In this paper, power quality disturbances will be assessed by Short-Time Fourier Transform which enhances PQ analysis under dynamic conditions.