UHV AC and DC gas-insulated bushings

Present day oil-paper condenser bushings and potheads perform well at today´s voltage levels and with today´s cables and terminal equipment. However, it appears that with increased voltages and in certain special situations other types of terminations might be necessary or economically desirable. In particular, there appear to be three areas where gas terminations will be most useful: 1. Where the main insulating material of the device or cable is gas. 2. Where there are large dielectric losses in conventional insulating materials at UHV levels. 3. Where there are large high frequency (≈ 240 Hz) dielectric losses in conventional insulating materials during induced voltage tests. This may be more significant if the induced tests decrease in voltage and increase in time.