C_(4)F_(7)N/CO_(2)二元混合气体雷电冲击绝缘特性研究

Study on Lightning Impulse Insulation Characteristics of Binary C_(4)F_(7)N and CO_(2)Mixture

SF_(6)替代气体在电力设备中的应用研究越来越广泛,其中氟化腈C_(4)F_(7)N被认为是目前最具潜力实现SF_(6)替代的气体之一。文中结合隔离开关断口结构,研究了C_(4)F_(7)N/CO_(2)二元混合气体的雷电冲击绝缘特性。基于混合气体绝缘试验平台,重点分析了气体种类,电压极性、充气气压、电极距离、C_(4)F_(7)N占比对50%击穿电压的影响规律。试验结果表明:在研究范围内,50%击穿电压随着充气气压、电极距离和C_(4)F_(7)N占比的增大均呈升高趋势。当充气气压升高到100、150、200 k Pa时,对应50%击穿电压(20:80,15 mm)分别为109.7、152.9、179.6 kV;当电极距离为5、10、15 mm时,50%击穿电压(35:65,200 k Pa)分别为73.4、138.5、203.0 kV;当C_(4)F_(7)N占比为20%、35%和50%时,50%击穿电压(15 mm,200 kPa)分别为180.0、203.0、218.4 kV。

The study on application of alternative gas to SF_(6)gas in the electrical equipment is becoming more andmore widespread,in which fluoronitrile gas(C_(4)F_(7)N)is considered presently as one of the most potential alternativegas to SF_(6).In this paper,the lightning impulse insulation characteristics of binary C_(4)F_(7)N/CO_(2)mixture are studiedwith combination of the break structure of disconnector.Based on the insulating test platform of the mas mixture,therule of influence of kinds of gas,voltage polarity,filling pressure,electrodes distance and C_(4)F_(7)N proportion on 50%breakdown voltage is analyzed in particular.It is shown by the test result that 50%breakdown voltage tends to risewith the increase of gas filling pressure,electrode distance and C_(4)F_(7)N proportion.When the gas filling pressure ris-es to 100,150,200 k Pa,the corresponding 50%breakdown voltage(20:80,15 mm)is 109.7,152.9,179.6 kV,re-spectively.When electrode distance is 5,10,15 mm,the 50%breakdown voltage(35:65,200 kPa)is 73.4,138.5,203.0 kV,respectively.When C_(4)F_(7)N proportion is 20%,30%and 50%,the 50%breakdown voltage(15 mm,200 k Pa)is 180.0,203.0,218.4 kV,respectively.