Plasma arcing is a common phenomenon during contact separation of high voltage direct current (HVDC) relays. In short circuit situations, a rapid increase of direct current initiates the separation of relay contacts, and hence arc formation at the contacts. To this day, the presence of these arcs poses a great challenge to relay manufacturers. Mainly because the arcs excessively heat, melt, boil, and vaporize the contact spots, and as such the relays are mostly damaged afterwards. A detailed understanding of the exact processes within the relays under such high currents during contact separation is therefore required to prevent complete damage of the relays. In this work, the contact separation of a Panasonic AEV14012 relay is being investigated using simulations. A time dependent current, ranging from 0.2 to 2.5 kA is applied to a gradually opening relay. The initial results demonstrate the plasma arc formation and time dependent arc growth at both contact spots of the relay. It is established from the results that; the temperatures of the arcs are higher than the melting temperature of the contact materials of the relay. It is therefore expected that; long arc dwell times will lead to permanent damage of the relay contacts.

The authors acknowledge the funding of the European Regional Development Fund (EFRE), and the collaboration with Panasonic Industrial Devices Europe GmbH, as part of the ARKE project.