Electronic circuit for accurate measuring of lightning continuous currents sensed by Rogowski coil

This paper is dedicated to the question of measuring lightning continuous currents on the basis of a Rogowski coil. A precise capturing of lightning continuous current (CC — upward lightning from tall objects [1]) via Rogowski coil is one of the most difficult issues. First of all, the parameter ranges of CC should be known in order to design of precise measuring equipment on the basis of Rogowski coil. One of such important parameter of CC is its range of rate of change di/dt. The necessary data of CC has been obtained by real measurements carried out at ORS Gaisberg communication tower in Austria [2], [3], [4]. Also, the common difficulties by measuring of CC on the basis of Rogowski coil, such as superimposing of lightning impulse currents during CC, appropriate time constant for integrator, are discussed. Initial investigation by designing of appropriate measuring circuit was done with help of network simulation software. Then the optimized circuit was built and tested in the lab. The results of simulations as well as measurements are presented.