Wavelet-demodulation-method based out of step detection and damping estimation in Japan campus warns

Abstract

Some previous research based on Fast Fourier Transform (FFT) estimated the damping ratio and frequency oscillation from Eigen value of the matrix associated to a Single Machine Infinite Bus (SMIB) model. Damping constant can be calculated for every 20 minutes cycles. However, it failed to explain how to calculate the damping ratio without associating the system to a SMIB Model. Furthermore, there was no way to verify the validity of the analysis since no network parameters could be included in the calculation. This paper promotes a novel approach in analyzing Phasor Measurement Unit (PMU) data to identify out of step phenomena and the calculation of damping ratio by applying a Continuous Wavelet Transform (CWT) algorithm. A linear regression method is performed to extract the damping ratio from the wave skeleton. The validity of the method is verified by comparing the calculated and real data from mathematically generated signals with known parameters.