My existing design is using CT to measure the current through the primary of my welding transformer. this current is of the order of 100A-400A. The value obtained from CT is multiplied with the transformer ratio to determine the secondary current. In the new design I am planning to use the secondary current as this will give me more reliable result. This secondary current is very high upto 25000A this current is not measurable by my CTs. Thus my inclination is towards Rogowski.

Regards,
Prahlad Purohit