A polyphase 500 kA current measuring system with Rogowski coils

A polyphase current measuring system is described. The design parameters are given, followed by theoretical consideration of how they can be met. The practical realisation, as well as some actual results, are given. It is shown that 450 kA peak AC currents with DC components, having time constants up to 250 ms, can be measured within 2% accuracy. The main advantages of this system are the potential-free measurements and the low cost compared to shunt or CT measuring systems.