Optimisation of End Insulation Design in Power Transformer

Abstract

The power transformer is an important component in power system that must be highly efficient and reliable in peration. Insulation design in power transformer is one of the important factors for determining reliability and size. It is essential to find a compact optimal design for insulation that satisfies the technical specifications with minimum manufacturing cost. In the transformer insulation design, the top end and bottom end insulation between winding and yoke of a power transformer is one of the important factor determining the total window height of the power transformer; hence optimization in the end will result in reduction in total cost and size of the transformer. In this paper electrostatic finite element analysis of power transformer end insulation is carried out, the cumulative stress distribution for each oil gap is determined and safety margin is evaluated by comparing it with industrial withstand curve. The value of top end and bottom end clearance of winding to yoke is optimised so that the value of window height is minimum and the end insulation design is reliable.