Analysis of the three-dimensional hybrid electric fields and the related electrostatic induction effects of 800Â kV DC and 500Â kV AC parallel transmission lines considering environmental factors

With the great development of ultra high voltage (UHV) transmission technology, there exist some 800 kV DC and 500 kV AC parallel transmission lines sharing the right of way in China. Due to hybrid electric field induced by 800 kV DC and 500 kV AC parallel transmission lines, the electromagnetic environment of the parallel lines will become more complex compared to that of either individual line. Furthermore, environmental factors such as relative air humidity, relative air density and wire surface equivalent roughness coefficient will influence hybrid electric field along the long transmission line from west to east China. This paper first establishes the equivalent model of transmission lines, human body and rain drop. Afterwards, the three dimensional electric field and ion flow field below the 800 kV DC and 500 kV AC parallel transmission lines are calculated by combining the 3-D modified CSM (charge simulation method) and the Deutsch hypothesis respectively. Next, different hybrid electric field distributions are obtained with different environmental factors. Finally, related electrostatic induction effects on human body under the parallel transmission lines are also analyzed. It is concluded that the induced currents on the surface of the human body are within the range of limited values specified by INCIRP with different environmental factors.