Simulation and Development of Rogowski Coil for Lightning Current Measurement

The dielectric strength design of a load device is very important for preventing and reducing accidents caused by lightning current. The size of a lightning current is accurately measured to calculate impulse withstand voltage for designing dielectric strength. An electric current sensor should be designed to secure accuracy and economic viability and in this paper, Rogowski coil thus was selected to measure lightning currents in the 100 kA range. This paper analyzed design elements to make a Rogowski coil, with the help of a MATLAB simulation and parameter values were estimated according to the coil structure (coil diameter in fixed external diameter, number of turns, etc.). In the process, a passive integrator was applied while employing an RC element, and a program-based low pass-filter was implemented to remove noise occurring at the initial part of the current waveform. Experiments were also conducted up to the 8/20 μs 100 kA range with an impulse generator. This paper verifies that the output value of the Rogowski coil is accurate as it stood within 5%, when compared with the standard CT.