CORRECTION OF THE METHOD FOR MEASURING THE AMPLITUDES OF THE CURRENT OF THE IMPULSE ALONG THE LONG EARTH ELECTRODE

Abstract

An improved method for measuring the amplitude reduction of the lightning current impulse as it flows from the beginning to the end of long horizontal earthing arrangement using ferromagnetic recorders has been substantiated. Two existing methods of pulse amplitude measurements at high voltages, the magnetic recording method and the method using a shunt, are used in justification. It is noted that in a number of cases it becomes necessary to determine the decrease in the pulse amplitude as it flows on a long object. This leads to the need to develop a method for performing such measurements. As an example, a long horizontal earth electrode was investigated when a lightning current pulse moves on it. Based on experimental studies in natural conditions, an improved method for measuring the decrease in the amplitude of the lightning current impulse along a long earth electrode is proposed. The proposed method has a measurement error not exceeding 10 %, and allows simultaneous measurements of the amplitude of the current strength at given points of the object, which can amount to tens or even hundreds. This method is implemented in a simple design and has an affordable manufacturing cost. The results of the experiments performed make it possible to recommend the corrected measurement method for practical use on existing electrical installations. The use of ferromagnetic recorders for recording and measuring the lightning current in areas of complex earthing arrangements is relevant for practical reasons, which include the possibility of measuring during a long wait and long-term storage of measurement results, does not require additional power sources and provides the possibility of synchronous measurements at various points of the grounding device. An important feature of the method is safety for technical equipment and personnel.