Epoxy bushing used in medium voltage switchgear

The paper describes design and development of a new bushing for the use in medium voltage metalclad switchgears with metal compartments. The bushing has been developed using a two dimensional quasistationary electromagnetic field on the basis of finite element method. Various combinations of conductive, insulated and earthed parts, connected with the bushing have been treated in the development phase. The calculations of electric field have been used as a basis for the definition of bushing's dimensions, geometrical form of conductive parts (fixed and withdrawable contact) and distances between conductive and earthed parts. The bushing, designed on the basis of simulation calculations' results, is made of epoxy pitch.