Experimental studies on discharge initiation from an icicle tip under DC voltage

Electric discharge between the tip of an icicle and a plane electrode has been studied because of its relevance to the flashover of high voltage ice-covered insulators. Using an icicle/iced-plate system, the corona discharge at the icicle tip was investigated under DC voltage. The influence of different parameters such as gap distance, temperature and water conductivity on the corona inception voltage (V_inc) was examined and analysed. The corona discharge process was depicted and the influence of the corona discharge on the icicle tip was illustrated. A novel discharge characteristic under the icicle tip was found when T=-5°C according to under the metal electrode, which needs to be verified further. All results will improve our understanding on discharge activities under atmospheric icing and are available to find solutions to improve insulators characteristics.