A Simulation Model for Electrical Tree in Solid Insulation Using CSM Coupled with GAs

A new model for investigating the growth of electrical tree in solid insulation using hyperbolic needle-to-plane gaps is used. Accurate computation of electric field is a pre-requisite for calculating the growth of electrical tree. The electric field distribution is obtained from Laplace´s equation by treating the tree structure as an extension of the stressed electrode i.e. conducting medium. The electric field is redistributed during each growth of the electrical tree. This is achieved by using charge simulation method coupled with genetic algorithms. Series of vertical and inclined line charges are used for simulating the tree, for these inclined line charges, a coordinate transformation is performed. Then, the electric field is calculated in the original coordinate system. The used needle tip radius is 3 mum while the gap spacing varies from 0.3 to 15 mm. The results have been assessed through comparison with experimental data.