Parameters of the Electric and Magnetic Field Waveforms Associated with Lightning Return Strokes

초록

One of the topics concerning electromagnetic compatibility of modern electronic circuits is to take protection from transient overvoltages caused by not only lightning return strokes but also induced lightning discharges. In this paper, the vertical electric and horizontal magnetic fields from lightning return strokes were measured and analyed. The electric and magnetic field waveforms associated with lightning return strokes have several large subsidiary peaks which decrease with time. There were not much differences between the electric and magnetic field waveforms when the distance from lightning return strokes to observation station is more than 50km. Averages of 10-90% rise times of electric fields are 4.65us for the positive lightning return strokes and 3.29us for the negative lightning return strokes, respectively. Also in the positive and negative lightning return strokes,averages of the zero-to-zero crossing times in the wave tail of magnetic fields are significantly longer than those of electric fields.