Insulation Properties of Liquid C6F12O for the Use in Eco-Friendly Transmission Equipment

In order to investigate the possibility to use liquid C
₆
F
₁₂
O as a SF
₆
substitute for environment protection and the influence of C
₆
F
₁₂
O liquefaction in gas mixtures on electric field distortion, the insulation and dielectric properties of liquid C
₆
F
₁₂
O are tested by AC break down experiments and broad dielectric spectroscopy (BDS). For analyzing and discussing the experiment results, the molecule parameters (e.g. geometry parameters, potential energy, dipole moment) of C
₆
F
₁₂
O, SF
₆
and main components in insulation oil are calculated by density functional theory (DFT), Becke, Three-Parameter, Lee-Yang-Parr (B3LYP) method, and 6-311g** basis sets. The results show that, the insulation property of liquid C
₆
F
₁₂
O is sensitive to electric field strength. And it is about 3 and 0.55 times that of SF
₆
(1 atm) and insulation oil respectively, which is mainly attribute to the molecule geometry size. The permittivity ε
_r
and tanδ of liquid C
₆
F
₁₂
O are about 4 times that of insulation oil, due to its higher dipole moment of 0.79 Debye and lower resistivity. The high ε
_r
may lead electric field distortion and flashover easily. Since the higher insulation property of liquid C
₆
F
₁₂
O, it may be used as SF
₆
substitute in transmission line. Besides, based on its low freezing point, high clean ability, strong flame extinguishing ability and large ε
_r
, the liquid C
₆
F
₁₂
O still has potential application prospects in power capacitors or circuit breakers at low temperature.