抄録
The recent trend in the development and the application of Vacuum Circuit Breakers (VCBs) as an environmental friendly equipment for electric power transmission and distribution is described. Using VCB's for circuit breakers and switchgear and extending the range of application of VCB's lead to reduce the usage of SF6 gas, whose global warming potential is approximately 23900 times that of CO2. The rated voltages and interruption currents of VCB's have increased up to 145 kV/40 kA for single break due to the improvement of the electrode materials and structures. Also, SF6 gas free switchgear up to 84 kV using compressed dry air insulation systems have been developed.