Vector Integration And Traveling Wave Distance Measuring Technology Of Single-phase Ground Fault In Small Current Grounding System

The power grid mainly is olated neutral, neutral grounding via arc suppression coil, the neutral point of high resistance grounding and neutral grounding via low resistance operation mode in our country.The method has the advantage of single-phase ground current is small and can not form a short circuit, the safe operation of power system can continue to run rules of order 1 ~ 2h, duty officer may be processed offer the problem. However, if the ground fault has not been found in timeor discovered is not timely treatment, as the non-fault relatively higher voltage, it will happen multi-phase short circuit and force the power supply interruption and affect the normal production. At present, most network are installed on the ground fault detection by insulation monitoring devices, and in accordance with grounded three-phase voltage instruction value of the different tables. However, the reality is not always the case, Most single-phase ground fault voltage grounding relatively lower but not the zero, non-fault voltage is increased but relatively less than the line voltage.Application the not neutral ground, with resonant grounding in power system s,ingle-phase ground fault of non-effective vector features in the project, and apply the distance estimates by the traveling wave fault location method, indor to improve single-phase power system reliability of non-effective ground fault is developed distribution system, information the single-phase ground fault detection of device fusion and vector-based traveling wave method.This paper studies the following:1.Describes the Basic principles of vector analysis,Space pulse width modulation, compared the reference waves with carrier, Usually chose the triangular wave carrier, Switch to switch as the basis for state modulated carrier wave in accordance with the intersection point.2.Current the three-phase power three-way voltage, three-way real-time measurement by digital signal processor, and operation of data processing and analysis by digital signal processor, output the SPWM waveform of three-phase. To in-depth study the feature vector of the three-phase electrical system ground fault occurs.3.Propose a new method of three-phase three-phase line voltage to detect which phase ground fault occurred by application of a new method of basic Space Vector and Information Fusion, The integration of vector analysis and cluster analysis method into the neutral point non-effectively grounded system, single-phase ground fault diagnosis, proposed integration of vector analysis and cluster analysis to neutral non-effectively grounded system, single-phase ground fault diagnosis, analysis of non-effectively earthed neutral ground fault power system in case by vector characteristics, provide a basis theoretical of vector analysis and vector information of the fusion of clustering analysis in single-phase power system fault diagnosis, and determine fault phase quickly.4.Study the technology of neutral non-effectively grounded system traveling wave distance measuring, Positioning the Principle A Single-Ended fault location, System line of small current grounding fault line of all types of transient characteristics of wave and Analysis of the traveling wave in the propagation characteristics of distribution line, To achieve power distribution line fault locator by A Single-Ended fault location, and gives the process of algorithm.5.In this paper,we compare the method of many neutral non-effectively grounded system, ground fault diagnosis, characteristics of the vector by single-phase ground fault occurred, compared the advantage of neutral non-effectively grounded system- ground fault diagnosis method of vector integration, proved effectiveness of this method to solve neutral non-effectively grounded system-ground fault.