Research On Fault Diagnosis Of Transmission Network And Action Performance Analysis Of Relay Protections System

With the expansion of Power System scale and the increase of voltage grade of transmission lines, high voltage (HV) transmission lines that exceed 110KV have increase day by day. As the important linked hinge in Power System (generating, transmitting and distributing electricity), the fault of the HV transmission lines will affect the security of modern Power System. Therefore the exact and fast fault diagnosis and analysis for HV transmission lines can provide important guarantee for deciding restore decision-making rapidly. In addition, on the basis of fault diagnosis, furthermore, by analyzing the performance of the protection action, staff can deal with incorrect protection action in time. It is significance to improve the system's safe operation.After power system malfunction, current and voltage have damped direct current and high frequency harmonic. This paper has chosen the full-wave difference Fourier algorithm in filter, which can restrain dc component and filter out high harmonic component effectively. The precision of fundamental wave that full-wave difference Fourier algorithm filter extracts is higher than non-difference Fourier algorithm filter, which provided a guarantee to result of fault diagnosis and equipment performance analysis.When it comes to analyze the performance of primary and secondary equipments in a transmission network, the entire topology of the network is required. This article propose a Topological analysis method based on Directed graph, which is easily implemented and yields to a equipments performance analysis method which can assess the performance of breakers and protections in a entire transmission network.And then the article modules a 110kV transmission network, simulates various types of fault and gets sufficient data . Take the distance protection for instance data derived from simulations is used to test the protection performance under different types of fault and good result turns out .The author developed a " high voltage transmission fault and protection performance analysis system " by VB, which implements the fault playback , symmetrical components analysis , fault detection , fault location , protection performance analysis etc. that provides helpful fault information to operators and reduces manpower.