Leakage currents on naturally contaminated porcelain and silicone insulators.

The leakage current measurements on standard post insulators and on rod insulators without sheds were carried out. The porcelain and silicone rubber insulators were tested at Glogow station under the voltage of 75 kV. It was shown that the currents on porcelain insulators are sometimes greater than the currents on silicone insulators. However, the currents on both insulator types are often similar. Silicone rubber insulators are more contaminated than porcelain insulators. The current analysis has been made using the static theory of pollution flashover