Radiation Characteristics of Electrical Fast Transient/Burst in Coal Mines

To study the radiated disturbance caused by electrical fast transient/burst (EFT/B), the frequency spectrum of single EFT/B pulse waveform was analyzed by Laplace transformation. The analyzed amplitude spectrum of EFT/B was up to 1 GHz. Analytical expressions of electric dipole radiated electromagnetic fields excited by EFT/B were deduced by using the radiated theory of time-varying current source. The numerical simulation was implemented. Results in time domain show that the radiated electromagnetic fields are proportional to the peak current of EFT/B pulse; the radiated electric field is dominant; the radiated magnetic field is relatively weak and the field strength attenuates with the increase of distance rapidly. The radiation disturbance caused by EFT/B could be observed obviously from the experiments of switching on or off inductive load in a coal mine.