There exist two technical solutions for a 1 100 kV GIS in the State Grid of China Ultra High Voltage AC Pilot Project.One adopting a double-break circuit breaker with a closing resistor
whose disconnector has a resistor;the other adopting four-break circuit breaker with closing resistor
whose disconnector has no resistor.This paper introduces the two technical solutions from such aspects as gas pressure
dielectric dimension
choice of interrupting units
specification of a circuit breaker with a closing resistor
and design of disconnectors.Moreover
it illustrates the difference between the two solutions in layouts for UHV GIS and HGIS substations.Conclusions are drawn that both solutions have self characteristics and can meet the requirements of UHV substation for technical parameters and layout.