CF_3I/N_2混合气体中绝缘子沿面闪络特性的研究

Research on Surface Flashover Characteristics of Insulators in CF_3I/N_2 Gas Mixtures

文中以SF6／N2混合气体作为比较，研究了CF3I／N2混合气体中绝缘子在工频电压和正、负极性雷电冲击电压下的沿面闪络特性。结果表明：在0．1-0．3MPa下，CF3I／N2混合气体中绝缘子的工频闪络电压和雷电冲击闪络电压均随气压升高而增大；在较低气压下，CF3／N2混合气体中绝缘子的负雷电冲击闪络电压比正极性下要低，而当气压高于某临界值时，负极性下闪络电压又会高于正极性：绝缘子在含30％CF3I气体的CF3I／N2混合气体中的绝缘性能基本介于含20％／30％SF6气体的SF6/N2混合气体中的绝缘性能之间，可以为CF3I混合气体替代SF6混合气体应用于高压气体绝缘电气设备中提供参考。

With reference to the test results for SF6/N2 gas mixtures, the surface flashover characteristics of insulators in CF31/N2 gas mixtures under AC power frequency and lightning impulse stresses are studied. Results show that between 0.1 MPa and 0.3 MPa, the flashover voltages in CF3I/N2 gas mixtures of the insulators under study increase with pressure. Moreover, under a low-pressure condition, the flashover voltage under negative lightning impulse is lower than that under positive lighting impulse. However, when the pressure exceeds a certain value, the flashover voltage under negative lightning impulse becomes higher than the value under positive situation. In gas mixtures with 30% of CF3I, the insulation performance of the insulators is equal to the insulation of gas mixtures which contains 20% to 30% SF6. This research provides a reference for the application of CF3I gas mixtures in high-voltage insulation devices.