Abstract
Since the electrical environmental factors such as electric field, ion current and ion density under HVDC transmission lines, are regarded as important factors relating to biological effects, measurements have been conducted in many countries.
One of important concerns in Japan is the electric shocks (similar to carpet shocks) which are caused by charged voltage due to ion current flows into the human bodies wearing shoes with highly resistive sole under HVDC transmission lines. Consideration is given to the prevention of such shocks in designing the height of the HVDC transmission lines.
In order to clarify the characteristics of ion flow electrification, long-term-measurements have been carried out under HVDC test lines since 1971 in CRIEPI.
Charged voltage is a key factor in determining the height of line conductors, because the reduction in charged voltage influences directly the cost of DC transmission lines.
Therefore, a series of tests and analysis were carried out in CRIEPI as a part of the research project for evaluation of the electric environment and corona effects under HVDC bipolar double circuit transmission lines.
This paper describes the influence of conductor height, pole spacing and pole arrangement on the charged voltage and proposes an empirical equation to estimate the charged voltage on the basis of long-term-measurements.
