The Analysis And Research Of Switchgear Characteristic Gas Composition

Switchgear connected to the primary equipment and secondary equipment is a key equipment of power system, its operation status is related to the reliability of the entire power system. Due to inevitably internal insulation defects will produce partial discharge, eventually leading to the loss of overall performance of the insulation and cause fault. Getting inspiration from the internal partial discharge detection and diagnosis methods of the quantitative detection of SF6 decomposition component for GIS, put air decomposition component detecting partial discharge of switchgear and diagnose the situation. The main work and conclusions are made mainly carried out as follows:(1) Using MS software to calculate the air discharge reaction heat and analyze the mechanism of air discharge component decomposed. Air discharge will produce stable CO, NO2 and volatile O3, NO3, N2O5. CO main production pathway is the oxidation of C element, followed by electron impact CO2 molecule; N mainly is derived from the reaction of N2 with O, followed by electron impact N2.(2) Developed air discharge fault simulation platform, and produced four typical defects, using of pulse current discharge method measure discharge capacity model, and preliminary study the air decomposition characteristics of typical defects. The results showed that in the free metal particles have a special product NO, The CO, NO2 under metal protrusion, insulator gap and insulator surface contamination defects are presented saturation growth with varying degrees.(3) Since the switchgear equipment is semi-enclosed type, simulated component gas diffusion motion in the FLUENT hydrodynamics platform and carried out air discharge test under real switchgear. The simulation results show that component gas can accumulate in the point to the detection limit of device under the switchgear connected the atmospheric gases and set point in the lower part of the cable compartment is conducive to concentration detection. Since the discharge under real switchgear more than simulations, the saturation phenomenon in the concentration of component significantly greater than simulation, but both are in the overall trend showing a saturated linear growth trend.Through this study we found that the using of air decomposition characteristics under the effect of partial discharge to troubleshoot switchgear equipment is feasible. Results of this study for future research the air decomposition characteristics and decomposition mechanism under the effect of partial discharge has laid a solid foundation platform.