Research On GIS Partial Discharge Signal Propagation Characteristics Of Typical Defects Based On UHF Method

With smart grid technology has matured, and users continue to improve the reliability of power supply requirements, For its safety, reliability and long maintenance intervals advantage in the power system, GIS is more widely used. The faults in GIS operation is mainly insulation faults, and the detection of insulation faults mainly based partial discharge detection. UHF partial discharge detection method inspired by the ultra-high frequency (1500MHz～3000MHz) signals, with good anti-interference, GIS is used to detect partial discharge ideal. In order to study on-line monitoring of UHF sensor rational distribution plan, electromagnetic signal propagation and attenuation characteristics in GIS were studied in the paper.In order to study the propagation characteristics of electromagnetic signals, we use simulation software XFDTD to analyze GIS model. First, we use CREO2.0build a GIS solid model and import XFDTD. Compared to traditional simulation Gaussian pulse, we use the typical defects measured discharge pulse as the excitation source to import software. Gaussian pulse signal pulse and five typical defects as the excitation source discharges study differences in their spread within the GIS. Because of its reliability and close to the ideal pulse discharge, we use cutting-edge high-voltage conductor discharge pulse as the excitation source electromagnetic signals through the direct study of the cavity, insulators, L-type and T-type branch branches attenuation. Also studied the effects of different diameter casing and inner guide rod and different length of the cavity electromagnetic wave propagation characteristics.In order to make research more accurate, the paper design flaws and defects in two corona typical floating potential defect model, put it to a dedicated GIS bouy analog cable shield of Beijing EPRI laboratory, and gradually pressing it discharge. Use English DMS UHF detector test, observe the three-dimensional diagram PRPD observed partial discharge occurred. Use the system comes with three built-in UHF partial discharge sensors detect electromagnetic waves generated and analyzed and processed with an oscilloscope. Then position the body for GIS analog simulation calculation, the simulation results with comparative analysis of experimental results further validate the correctness of the conclusions.