The influence of space charge and gas pressure during electrical tree initiation and growth

The analysis of the sequence of partial discharges that occur during the growth of electrical trees shows that local space charges play an important role, especially at the early stage. In the space charge build-up, that occurs within the polymer as a consequence of the partial discharges a marked polarity dependence can be found. At the late stage of the tree growth this difference diminishes and the gas pressure in the tree channels is the decisive parameter