switching impulse

[royclh]

hi, is there any hand calculation method available that can roughly determine the switching overvoltage at different voltage level and its propagation in a network? I know the value can be determined via the simulation program. Any document you can refer me to will be greatly appreciated. Many thanks

 

[prc]

Switching impulse values corresponding to various system voltages are given in various national standards.What is the need for hand calculation ?

 

[royclh]

IEC standard does not specify any switching impulse test value below 245kV. There has been a debate about whether the switching impulse test should be performed in a large wind farm below 245kV. Basically, I hope to find out if there is any quick hand calculation method that can give me a rough idea what is the suitable level of switching impulse test to be performed if required.