Partial discharges and breakdown in C₃F₈

Traditional search processes of gases or gas mixtures for replacing SF₆ involve time consuming measurements of partial discharges and breakdown behaviour for several voltage waveforms and different field configurations. Recently a model for prediction of this behaviour for SF₆ was described in literature. The model only requires basic properties of the gas such as the critical field strength and the effective ionization coefficient, which can be obtained by swarm parameter measurements, and thermodynamic properties, which can be calculated. In this paper, we show for the well-known and electronegative gas octafluoropropane (C₃F₈) that it is possible to transfer the model developed for SF₆ to this gas to describe the breakdown behaviour of C₃F₈. Thus the model can be beneficial in the screening process of new insulation gases. (paper)