An approach to the optimum insulation design of GCB interrupter

The optimum dielectric design of gas circuit breakers (GCB) in a consistent design philosophy is described. Many electric field calculations were carried out on 3 GCB models and the relation between the key design parameters such as distance between tank and shield, major radius of shield electrode and full open distance were analyzed. As a result, it was found that there is a minimum curve in the relation between full open distance and the electric field strength. Using this minimum curve and the allowable electric field strength, we can design the optimum GCB structure. It is also shown, as an example, how to design the optimum GCB of 300 kV by using 3 GCB models.