Optimal electric design of condenser graded high voltage AC bushings

The application of Genetic Algorithm for optimal electrical design of high voltage bushing concentric foils in transformers is investigated. Condenser-bushings contain concentric conductive foils which are isolated against another. By adjusting the number, diameter and length of these cylinders as well as the electrical strength of insulating material between foils, the voltage drop and also electrical stress in the core and along the surface can be affected by variation of partial capacitances between the conducting cylinders. This paper aims to find optimal design of concentric conductive foils for having lower maximum and well-distributed electric stress and also a constant voltage drop for different layers subject to some practical constrains by using Genetic Algorithm optimization method.