Research On New Method Of Power System Faults Detection

Along with the development of power system, more and more generators and EHV transmission systems are put into operation. There come many new situations, such as the lengthening transmission distance, the heavier load, the increasing transient elements during the transient process. These new conditions influence the correct working of relay protections.Based on the analysis of power system faults, this article takes a research on tow methods that currently used in power system faults detection, and discusses their disadvantages. Then the article gives a new fault detection method.The main job of this research is:(1) Analyze the operation situation of power system during faults; pay attention to the traveling wave on the three-phase transmission line; study the equation of voltage on three-phase transmission line with impedance capacitance coupling between phases; contact the voltage on any point with the fault voltage, study the singularity of the voltage signal in fault point, and make it to be the base of the new fault detection method;(2) Apply the singularity detection theory based on wavelet analysis to the power system faults detection, give a complementary criterion to current fault detection criterion, study how to select the basic wavelet, how to filter noise, how to detect the singular point or fault point, and finally give a total solution. The simulations prove it to be a quick, correct and effective fault detection method.