Underlying mechanisms and human perception thresholds in electric fields of high-voltage power lines
As part of the energy transition, the low-less transportation of energy over long distances becomes more important. Therefore, more direct current (DC) overhead power lines will be installed instead of the commonly used alternating current (AC) lines, and new hybrid overhead power lines will be formed through the combination of AC and DC lines on the same pylons. However, limit values for DC and hybrid fields do not exist and mechanisms of the human perception of electric fields have been rarely investigated in the past.
In our large-scale study including more than 200 participants, we determined perception thresholds for DC and AC electric fields, as well as the influence of ion currents and relative humidity (Kursawe et al., 2021). Moreover, an increased perceptibility of hybrid electric fields was found and further investigated in a follow-up study including 50 participants. These findings indicated a significant influence of the AC component on the perception thresholds. Our current studies firstly aim to determine the lowest perception threshold of hybrid electric fields and to specify the influence of the DC component on the perception performance. Secondly, we are investigating the underlying mechanisms of the human perception of electric fields focusing on the influence of individual body hair and hair characteristics.
All studies are conducted in our exposure laboratory at the University Hospital RWTH Aachen specially designed and build for this purpose. DC electric fields of up to 50 kV/m combined with ion currents of up to 550 nA/m2 can be generated. The maximum AC electric field strength at a frequency of 50 Hz is reached at 30 kV/m. The combination of both DC and AC (referred to as hybrid electric field) do not exceed values of 50 kV/m. Additionally, temperature and relative humidity can be varied independently in the exposure laboratory depending on the research question. Several safety precautions and measures were implemented to ensure a safe conducting of double-blind experimental studies. For a precise description of the laboratory setup and the technical implementation, see our publication (Jankowiak et al., 2021).
Dr. phil. Michael Kursawe
Kathrin Jankowiak, Ralph Kühn, Michael Kursawe