Research of Transient Voltage Disturbance Moments Detection Method Based on Discrete Orthonormal S-Transform

Power quality is one of the mostly concerned issues in modern power industry. Rapid and accurate detection of the begin-end moment of power quality disturbance signal is crucial to improve the power quality. As one of the high resolution transform algorithm, S-transform can extract the time-frequency information of disturbance signal, but the algorithm is computationally less efficient. The discrete orthonormal S-transform (DOST) that analyzes time-frequency parameters of the disturbance signal is proposed in this paper. First of all, the discrete orthonormal S-transform (DOST) is deduced from short time Fourier transform(STFT), then DOST is used to analyze common power quality disturbance signals such as voltage swell, voltage sag and momentary interruption, finally the disturbance moment is detected. Simulation result shows the effectiveness of the DOST algorithm.