Short time disturbance detection using DCT analysis in distribution system

This paper introduces DCT (discrete cosine transform) into short time disturbances detection. DCT coefficients of sampled signal about short time power quality disturbances (voltage sag, voltage swell and voltage interruption) in serious noises can be extracted through DCT transform, and a difference sequence can be extracted through DCT coefficients, then disturbance characteristics can be detected. Simulation results show that this method has a simple process, and can realize signal detection in heavy noises, and the detection results have a high precision.