Capacitive-resistive transition in gas insulated DC systems under the influence of particles on the insulator surface

Satisfying the requirements of recent energy transmission, like space saving installations, bridging vast distances between generation and consumption of energy as well as linking offshore wind farms, DC operated gas insulated systems are shifted into the focus. Compared to AC applications, the electrical DC field is, amongst others, determined by temperaturedependent conductivities of the insulating materials. After energising the system, the permittivity dominated electrostatic field is transformed into a quasi-stationary, conductivity dominated electrical field. Based on experiments, a CFD model was developed to pre-calculate the temperature distribution at various electrode temperatures. Following up, time dependent calculations show the changing electrical field distribution.…