Optimization of Electrode Contour for Improvement of Insulation Performance of High Voltage Vacuum Circuit Breaker

For the improvement of the electrical insulation performance of the vacuum circuit breakers (VCB) and vacuum interrupters (VI), the authors develop the computer-aided optimization technique based on the electric field calculation. For this background, the authors developed a computer-aided optimization tool for VCB and VI electrical insulation design. Using this tool, in this paper, the authors evaluated the several design variables necessary for optimizing the electrode contour of main contactor and center shield in VI. The influences of the various factors like area effect of breakdown, arrangement of VIs, etc. to the optimization result were investigated. The optimization results revealed that the electric field distribution in VI was greatly influenced by floating potential of the center shielding electrode. Finally it is concluded that the arrangement of VI in the VCB grounded wall should be carefully considered in the optimization and design procedure