In order to enrich the structure form of main circuit of RMU and meet the needs of different customers

akind of dry air insulated RMU with two-side disconnectors main circuit proposal is designed. In this proposal themain circuit structure form the disconnectors are arranged on both ends of vacuum main switch and the earthingswitch is arranged at the outgoing side is adopted. For achieving to meet dielectric requirement of dry air at zerogauge pressure and compact structure at the same time

the main circuit structure is optimized by way of enclosed in-sulation and uniform electrical field method. The electric field of key insulation structure is analyzed through theoreti-cal calculation and finite element simulation. The samples of 12 k V/630 A circuit breaker and load switch are devel-oped and the type test is finished.The product has excellent dielectric performance and the partial discharge of theproduct is less than 10 p C. The successful development of the sample has verified feasibility of technical proposal ofthe two-side disconnector and enriched the structure form of the gas filling RMU.