Development and installation of a test circuit for the reproduction of electric fields from high voltage direct current transmission lines in an exposure chamber

Summary

High voltage direct current (HVDC) transmission lines are used for decades for the transmission of high power over long distances through remote areas. With improvement in converter technology and changing demands on transmission grids, HVDC overhead lines will be increasingly used in dense populated regions like central Europe. For example in Germany, HVDC overhead lines will be used to transfer the energy from the northern offshore windfarms to the load centres in southern and western Germany. To limit the space used for overhead lines, DC and AC overhead lines are planned to be partially mounted on the same tower, thus sharing the same corridor. With this, human beings will be exposed to static and alternating electric fields in presence of ion currents. Therefore the effect of hybrid electric fields on human beings has to be investigated. To fulfil this task a study with two-hundred participants is planned at the RWTH Aachen University Hospital which will examine the ability of human beings to perceive the presence of such electric fields. A test circuit suitable for generating the needed DC and AC fields with and without ion currents is currently put into service. As the electric field at the ground emitted by an overhead line is uniform, not only one field generating electrode but also fourteen additional grading electrodes are used. By this, the uniformity of the electric field in the exposure chamber is secured. For creating the ion current and controlling its strength a special arrangement of another three electrodes is used. As the perception of electric fields also depends on ambient parameters like temperature and humidity, the electric field has to be generated in a closed exposure chamber where these parameters can be controlled. Because of the presence of the participant next to the surrounding electrodes on high voltage potential, the devices for the protection of the participant have to be of a high safety standard. This paper will present the technical requirements on the developed test circuit and the electrode arrangement design.

Additional informations

Authors

HERGERT, JENS, ASSELIN, JOHANSSON, EVANS

Keywords

Perception threshold, HVDC, Ion currents