New experimental system for the study of the effect of temperature and liquid to solid transition on streamers in dielectric liquids: application to cyclohexane

An experimental setup for dielectric testing of insulating liquids in the temperature range from -60 °C to +250 °C has been built. The system uses point-plane geometry, a sensitive differential charge measurement technique, a computer controlled temperature regulator, a photomultiplier and a pulse generator with a fast rise time. This paper presents a detailed overview of the functionality of the system and results obtained in cyclohexane under positive and negative polarity below and above freezing point. Pre-inception current, inception probabilities, streamer charge and emitted light from streamers are reported. The results found in cyclohexane at room temperature compares well to results obtained in other similar setups. A temperature dependence on the injected streamer charge for liquid cyclohexane under positive polarity was observed. No polarity differences were observed for any of the measured quantities in frozen cyclohexane.