The Influence of Free Wire-type Conducting Particles on SF_6 Sulfur-containing Decomposition Components Under Positive DC Partial Discharge

摘要

The safe operation of gas-insulated equipments is crucial to the whole power system. Free wire-type conducting particles within direct current (DC) gas-insulated equipments greatly threatens the insulation system by distorting the electric field and inducing partial discharge (PD) in insulation gas, And easily lead to accidents. Since SF_6 decomposes and generates a series of characteristic products under PD, the fault diagnosis and on-line monitoring of gas-insulated equipment can be realized effectively by analyzing these characteristic decomposition components and their variations of concentrations. In order to investigate the influence of free wire-type conducting particles on SF_6 decomposition characteristics under positive DC partial discharge, we establish a electrode system filled with pure SF_6 gas, positive DC partial discharge was generated by using a ball - bowl electrode, and three SF_6 characteristic decomposition components (SO2F2, SOF2 and SO2) were tested by gas chromatography mass spectrometer (GC/MS), finally we obtain the main features of SO2F2, SOF2 and SO2 under different diameters of free wire-type conducting particles. The effective generation rate r_(GMS) was calculated and the experimental data shows that, with the increase of the diameter of free wire-type conducting particles, the generation of SO2F2, SOF2 and SO2 is inversely proportional to that, and the generation rate of SO2F2, SOF2 and SO2 is different.