Disc insulator of electric power transmission line.
Relative permittivity of porcelain ε = 6,
Relative permittivity of cement ε = 2.
Dirt layer thickness 1 mm.
Dirt layer conductivity 30 uS/cm.
Porcelain thermal conductivity 1.4 W/K-m.
Air temperature +20°C, convection coefficient α = 10 W/K-m2.
Calculate the thermal effect of the leakage currents in the insulator.
Leakage current density distribution in the insulator (on the left), insulator temperature profile (on the right).