Power quality analysis on ehv transmission line using modified S-transform

This paper presents a new approach for power quality analysis using a modified S-transform on EHV transmission line. The excellent time frequency resolution characteristic of the S-transform makes it an attractive entrant for the analysis of power quality (PQ) disturbances under noisy condition and has the ability to detect the disturbance correctly. But it suffers from poor energy concentration in the time frequency domain. It gives degradation in time resolution at lower frequency and poor frequency resolution at higher frequency. The modified S-Transform scale the frequency components of power signal in an efficient manner to provide the improved energy concentration of the S-transform. Several power quality problems are analyzed using the Modified S-transform performed on EHV transmission line, the simulation results show that the Modified S-transform can effectively detect and classify different power quality disturbances.