The simulation of the early-time High-altitude Electromagnetic Pulse (HEMP) environment (El) with bicone-cage antenna in free space requires utilization of the spherical wave to reproduce the boundless plane wave....The simulation of the early-time High-altitude Electromagnetic Pulse (HEMP) environment (El) with bicone-cage antenna in free space requires utilization of the spherical wave to reproduce the boundless plane wave. The transient radiation of the antenna above the lossy ground is computed using the Finite-Difference Time-Domain (FDTD) method The determining factors of the field waveform are explored and analysed on the basis of the physical evolution process of the transient radiation. The typical waveform of the electric field and the field distribution characteristics, both of which are important for HEMP simulator design and the effect tests, are presented. The study indicates that the simulation should be analysed from the perspective of both environment building and simulator applications.展开更多
The strength of the power frequency electric intensity and magnetic field of the 500-kV double circuit transmission lines was calculated by using the equivalent charge method and the Ampere's Law, and the environm...The strength of the power frequency electric intensity and magnetic field of the 500-kV double circuit transmission lines was calculated by using the equivalent charge method and the Ampere's Law, and the environmental impact factors of the fields were evaluated. By optimizing the phase sequence, the frequency electric intensity and magnetic field strength can be reduced. Within a distance of 25 m from the center of the transmission line, the power frequency electric intensity and magnetic field strength fall off sharply with the distance increase. Finally, the best phase sequence and the minimum ground clearance of the transmission lines were obtained to meet the requirements of the least impact on envionment.展开更多
文摘The simulation of the early-time High-altitude Electromagnetic Pulse (HEMP) environment (El) with bicone-cage antenna in free space requires utilization of the spherical wave to reproduce the boundless plane wave. The transient radiation of the antenna above the lossy ground is computed using the Finite-Difference Time-Domain (FDTD) method The determining factors of the field waveform are explored and analysed on the basis of the physical evolution process of the transient radiation. The typical waveform of the electric field and the field distribution characteristics, both of which are important for HEMP simulator design and the effect tests, are presented. The study indicates that the simulation should be analysed from the perspective of both environment building and simulator applications.
文摘The strength of the power frequency electric intensity and magnetic field of the 500-kV double circuit transmission lines was calculated by using the equivalent charge method and the Ampere's Law, and the environmental impact factors of the fields were evaluated. By optimizing the phase sequence, the frequency electric intensity and magnetic field strength can be reduced. Within a distance of 25 m from the center of the transmission line, the power frequency electric intensity and magnetic field strength fall off sharply with the distance increase. Finally, the best phase sequence and the minimum ground clearance of the transmission lines were obtained to meet the requirements of the least impact on envionment.