Research On Multi-section Fault Location Method For Small Current Grounding System

At present,the national economy of our country is developing rapidly,the living standard of the residents is increasing,the demand of electric power is more and more high,the structure of power system is more and more complicated,but the reliability of electric power is higher.it is more burdensome to find fault location for small current grounding system.Although many scholars on the fault location of small current grounding network have a lot of research,the basic theory is relatively mature,but,in fact,the application is very few,with the system network more and more complex,making fault location more difficult,positioning accuracy is difficult to guarantee.Therefore,it is necessary to do in-depth research on this technology,and has very important significance.In this thesis,using the information collected from the multi points,the advantages of various positioning methods can be used to form a comprehensive fault location criterion,which makes fault location more accurate,and the method of line detection can be used to some extent.in this paper,the first half wave polarity method,the transient energy function method and the phase difference method are softened together to form an improved multiple section fault location method,in which each positioning method has its own advantages and disadvantages,which can be judged correctly under some circumstances,and it can't be judged correctly in another case.Therefore,the multiple-section localization method to determine.The method of fault location in multiple sections is that if there is a fault in a certain section,if there are more than two criteria to identify the fault of the section,then the fault is determined.In this thesis,the comprehensive criterion is verified by simulation in MATLAB,the localization ability of each method is validated,and the locating ability and reliability of fault locating in multiple sections are tested.The detection unit for the design of hardware and software.a simulation platform of 10kV power supply line is built,and the simulation platform is to replace the actual line with capacitance and inductance,and It is a small current grounding system with three lines.The signal is collected by voltage and current transformer,and zero sequence signals are obtained by signal processing.Analysis of the resulting signals,the fault locating ability of multiple section fault location method is validated experimentally.