An Algorithm To Locate Power-Quality Disturbance Source Based On Disturbance Measures And Evidence Theory

With the increasing complication in power grid and electricity load,power quality has become an important concern to customers and utilities facilities. Locating power-quality disturbance source is an important function in power quality analysis. It has instructive significance on disturbance sources location and the governance of grid pollution. This paper summarizes the research in the disturbance source location currently, and proposed a localization algorithm about power quality disturbance source based on disturbance measures and information fusion theory.The first problem has solved about the disturbance localization is determining the disturbance direction. The disturbance signal is complex when a disturbance event occurs, and different signals have different method in determining the disturbance direction. The paper uses wavelet transform to multi-scale decomposes and reconstructs the disturbance signal using wavelet transform, then extracts the low frequency signal and the high frequency signal. According to the different characteristics of the low frequency signal and the high frequency signal, proposed the discrimination methods of disturbance direction based on the transient disturbance power and the steady-state disturbance energy.The greater the disturbance intensity is, the higher reliability of the results of the disturbance direction is. Then proposing the concept of disturbance measure, and using the direction and the strength to portray the disturbance signal. Establishing the column vector of disturbance measure by the measure value of all monitoring points. Covered matrix is obtained by topology structure of the power grid .Calculating the column vector of disturbance measure and the covered matrix can obtain the possibility of the line exist disturbance source.Information fusion technology is an effective method to deal with the problem which has multiple criteria. Fusing the tow positioning results that based on transient components and steady-state components, finally it can get a better accuracy positioning results. Simulating the different types of disturbance by DDRTS, the disturbance data from simulating will be written into the location algorithm writhed by MATLAB program. Simulation results confirm its effectiveness and reliability.