Dynamic characteristics of the corona discharge during the energised icing process of conductors

Considerable differences exist between the energised icing process and the non-energised icing process of conductors. The main reasons that contribute to these differences are the complex interactions between the icing process and the corona discharge. To reveal these interactions, the dynamic characteristics of the corona discharge in energised icing process have to be studied. The energised icing tests of conductors are carried out in the artificial climate chamber. The short-term statistical characteristic and the long-term variance trend of corona properties are obtained by using the Q-V trace method. Experimental results are analysed as well. The results indicate that the distribution of the magnitude and the power of the discharge approximately obeys the normal distribution. Also, with the accumulating of the ice, the mean values of the short-term discharge power and the magnitude increase initially then saturation appears after the increasing period. The saturation time is related to the icing velocity of the conductor. When the electric field strength is >10 kV/cm, the icing velocity will decrease if the electric field is increased. The standard deviations of the magnitude remain in the same level when the electric field is varying.