• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2004.05a
• /
• pp.581-585
• /
• 2004

The wave shapes of electromagnetic pulses radiated from lightning discharges are significantly changeable one of the topics concerning on EMI/EMC of modern electronic systems is the efficient and economic protection of electronic circuits against transient voltages caused by not only by cloud-to-ground lightning but also by intracloud lightning discharges. In this work, in order to obtain the detailed information about lightning electromagenetic pulses, the electromagnetic pulses radiated from intracloud lightning discharge processes were measured and analyzed statistically.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.20 no.2
• /
• pp.81-88
• /
• 2006

In this study, the electric and magnetic fields measuring system were designed and fabricated to investigate the electric characteristics of lightning discharges. Frequency bandwidth of electric field measuring system ranges from 40[Hz] to 2.6[MHz] and its response characteristic is 2.1[(V/m)/mV]. Frequency bandwidth of magnetic field measuring system ranges from 300[Hz] to 1[MHz] and its response characteristic is 2.8[nT/mV]. Electric and magnetic fields due to intracloud lightning discharges were observed and their waveform parameters were statistically analyzed. As a result, waveform parameters of electric and magnetic fields are nearly independent of polarity. The mean rise times and the zero-crossing times of electric and magnetic fields are approximately $5.5[{\mu}s]\;and\;21[{\mu}s]$, respectively.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.19 no.6
• /
• pp.59-66
• /
• 2005

This paper presents some features and statistics of electromagnetic pulses radiated from intracloud lightning discharges. The LabVIEW based-measurement system of time-dependent electromagnetic fields was constructed. The frequency bandwidth of the measuring system ranged from 300[Hz] to 1[MHz], and the response sensitivity was 2.78(mV/nT). The resolution and the maximum recording length of the data acquisition system were 12(bits) and 100[ms], respectively. In the electromagnetic pulses radiated from intracloud discharges, a pronounced bipolar pulse appeared with one or more fast pulses superimposed on the initial front part of the bipolar pulse. The mean duration of intracloud discharges was $1.05{\pm}0.32[ms]$, and an average of about 8 outburst pulses appeared for a period.

• Journal of Sensor Science and Technology
• /
• v.5 no.2
• /
• pp.47-54
• /
• 1996

This paper deals with the electric field sensor and automatic measuring system of the time-varying space electric field produced by lightning discharges. The theoretical principle and the design rule of the measuring devices are investigated, and the semisphere-type electric field sensor and the signal process system are fabricated. From the calibration experiments, the frequency bandwidth of the measuring system ranges from 200 [Hz] to 1.56 [MHz] and the sensitivity is 0.96 [m V/V/m] as the amplification gain is 10. In addition, the electric field waveforms produced by lightning discharges are observed by the proposed electric field measuring system from June to August in 1995. The data is sampled with the time interval of 200 [ns] and is automatically recorded by transient signal analyzer(Necolet Pro 30), the resolution of which is 12 bit. And it is registered at personal computer. The electric field waveforms produced by intracloud discharge tend to be bipolar, with two or three narrow and fast rising pulses superimposed on the initial half-cycle.