Purpose/Aim
Tri-post insulator plays a significant role in electrical insulation and mechanical supporting inside GIL. In this work, the electric field distribution of SiC doped tri-post insulator inside a DC GIL was studied by using electric-thermal multi-physics simulations. The potential application of such tri-post insulator was discussed.
Experimental/Modeling methods
The electric-thermal multi-physics simulations were carried out by finite element method using COMSOL. The thermal field model was established considering thermal conduction, convection, and radiation process. The electric field model was established considering gas ionization and charge accumulation. The parameters of SiC doping epoxy resin used in simulations were acquired by experiments.
Results/discussion
The electric field concentration at interfaces were suppressed as the mass fraction of SiC in epoxy resin increased. The electric field regulation effects in this work are in-line with the previous researches that non-linear conductivity materials can modify local electric field in DC spacer and post insulator.
Conclusions
In this work, the electric field regulation effects of non-linear conductivity materials were studied by simulation, and the maximum value of electric field of tri-post insulator at the interfaces had a 32% decrease under DC voltage.
 

DC gas insulated transmission line,Multi-physics coupling,tri-post insulators,nonlinear condcutivity,Finite Element Method