Performance of Modified S-Transform for Power Quality Disturbance Detection and Classification

Faridah Hanim M. Noh (Universiti Tun Hussien Onn Malaysia)
Munirah Ab. Rahman (Universiti Tun Hussien Onn Malaysia)
M. Faizal Yaakub (Universiti Teknikal Malaysia Melaka)

TELKOMNIKA (Telecommunication Computing Electronics and Control)
Vol 15, No 4: December 2017

Detection and classification of power quality (PQ) disturbances are an important consideration to electrical utility companies and many industrial customers so that diagnosis and mitigation of such disturbance can be implemented quickly. Power quality signal consists of stationary and non-stationary events which need a robust signal processing technique to analyse the signals. In this paper, Modified STransform (MST) was used to analyse single and multiple power quality signals. MST is a modified version of S-transform with improved time-frequency resolution. The power quality signals that are considered in this study are voltage swell, sag, interruption, harmonic, interharmonic, transient, sag plus harmonic and swell plus harmonics. The performance of the proposed method has been studied under noisy and unnoisy condition. Hard thresholding technique has been applied with MST while analysing noisy PQ signals. The result shows that MST is able to give higher classification rate with better time and frequency distribution (TFD) spectrum of the PQ disturbances.