The sensitivity of C4F7N to electric field and its influence to environment-friendly insulating gas mixture C4F7N/CO2

摘要

C4F7N has excellent insulation performance. By mixing with CO2, it is the highest potential alternative gas to the most greenhouse effect gas insulating medium SF6, which is widely used in gas insulated high voltage electrical equipment. It is necessary to explore its insulation stability under different electrical fields before application. In this paper, the influence of electric field on C4F7N/CO2 mixture with different gas pressures and mixing ratios is tested, analyzed and compared with SF6 by experiment and calculation. It was found that the electric field sensitivity of C4F7N/CO2 gas mixture is much higher than that of SF6 and CO2, where it is easy for partial discharge to emerge under non-uniform electric field. The insulation performance of C4F7N/CO2 gas mixture is extremely susceptible to the internal electric field of electrical equipment, and optimization of the equipment internal structure to avoid uneven electric fields is needed.