Modeling, Analysis and Real Time Estimation of Voltage Sag and Swell for Power System Applications

Nowadays power quality is term widely used in power systems wherein the voltage, current, and phase angle are widely discussed and used. The Time Frequency Representation (TFR) provides a powerful method for identification of the non-stationary of the signals. This paper proposes a Discrete Orthogonal S-Transform (DOST) for analysis and visualization of voltage distortions with timevarying amplitudes. Voltage estimation and subsequently detecting the sag and swell are very important in determining the power system stability and quality. This paper presents two models to build the voltage shape with the knowledge of few parameters and detects voltage sag and swells accurately. Also the performance of each method has been compared with other to know the effectiveness of different models and their results are presented.