The Research On The Detection And Location Of Power Quality Disturbance Signal Analysis

With the rapid development of society, a large number of unbalanced nonlinear loads was put in production, power quality has been seriously affected. To explore the factors of power quality decline, timely find the reason, and to locate, To effective management and to compensate power quality is great significance. Due to the complexity of the actual environment of power quality disturbance, the existence of noise or compound disturbance. Detection of power qual ity disturbance, therefore, is a difficult research problems. In this dissertation, the single and composite power quality disturbance signal of power quality disturbance signal’s characteristics, the algorithm for detection and localization algorithm were analyzed and studied.First of all, the dissertation collection of Empirical Mode Decomposition experience added white noise and white noise caused by the residual, long operation time, and that there is no accurate detection of power quality disturbance. Puts forward the improved empirical mode decomposition Hilbert transform detection method of power quality disturbance. This method gain added white noise, the adaptive wavelet threshold denoising and Intrinsic Mode components to judge, disturbance signa l in the physical meaning of IMFs, at the same time effectively suppresses the modal aliasing phenomenon, and the better antinoise performance, shorter operation time. HT of IMFs component transform to disturbance information such as amplitude, frequency, beginend time, realize the disturbance signal detection.Secondly, the dissertation based on the four positioning methods of impedance real part of asymmetric voltage sag fault location inaccuracy shortcomings, proposed to improve the power energy positioning method of voltage sag source localization method. The method using the symmetrical component method and superposition theorem, the system of negative sequence power and energy eigenvalues for polarity judgment, can effectively solve the impedance real part positioning method in threephase voltage, current, the phase when positioning is difficult to meet the locating criterion at the same time, the existing positioning inaccurate phenomenon.Finally, respectively, for the power quality detection method with simulation of voltage sag source localization method, dissertation puts forward the feasibility and effectiveness of the method is verified through the validation.