GIS-based Finite Element Analysis Of Internal Defects PD Detection Technology

With the continuous development of domestic UHV network, the grid voltage level and capacity increasing, gas insulated switchgear because of its compact structure, long maintenance cycle, small occupation area and good insulation properties and other advantages, is widely used in electric power system. Due to the long run in high voltage and frequent operation, fault is occurred frequently in recent years in power system, therefore, insulation equipment is highly valued, and research of GIS internal defects has become a hot research at home and abroad.In this paper, according to the GIS internal high-voltage electrode spiked, electrode spikes and spherical particles of three kinds of typical defects, built the experimental platform of three kinds of typical defects. The plate-plate electrode as the experiment platform, the high-voltage electrode spiked, spherical particles and the electrode spiked in three typical types of defects between the high-voltage electrode plate and the low voltage electrode plate, respectively, using the pulse current method and the ultrasonic method of two kinds of detection methods for the detection of partial discharge, partial discharge patterns to find out characteristics of various defects the study of partial discharge, lay the foundation for real GIS electrical equipment within the typical defects.Partial discharge phase map is obtained GIS internal typical defects by ultrasonic method and pulse current method. Based on the GIS internal high-voltage electrode spiked, analysis of ultrasound signal electrode spiked and the high voltage electrode spherical particles three categories of fixed defects and pulse current signal phase map, pulse current method for the detection of ultrasonic inspection electrode spiked more sensitive, and ultrasonic pulse current method for detecting method of high voltage electrode spiked more sensitive. Through the analysis of partial discharge patterns and get the difference of the high-voltage conductor spikes, electrode spiked and spherical particles spiked.Through the simulation of the high-voltage electrode defect and spiked electrode defects result can reach main factors affecting the breakdown voltage is the gap distance and the distance between poles. The simulation data of different electrode spacing and spike length analysis between two kinds of spinal defect strength of electric field and voltage curve is a linear relationship, the intensity of electric field and the voltage is proportional to, but the intensity of electric field and electrode spacing is inverse proportion relationship. Comparison of the high-voltage electrode and a ground electrode spiked spiked electric field simulation results and the test results can be obtained simulation results are basically consistent with the experimental results, using diagnosis based on FEM of defects of equipment has a certain effect, plays a guiding role in experimental study.