Hi

Refer this paper from Cigre. There is plenty of material online available for it . 

Regards. 

Thank you Arun.

Hi,

Several methods work, I think.

1. the opening and closing resistor, most effective one and has been employed in GIS.

2. the magnetic ring, i think it's simple and useful, you can find some papers about it.

3. the RF resonator, issued by ABB, as attached.

4. metal oxide arrester, maybe too slow for VFTO.

5. terminal and capacitance components, etc. I'm not quite sure about them, you may find some articles in google.

regards!

good question