Abstract
Because the gas forced cooling type gas-insulated transformer was considered to be available up to approximately 60MVA, several types of liquid cooling large-capacity gas-insulated transformer have been developed. But liquid cooling type has a disadvantage of complex structure for liquid cooling.
In this reason, authors have been studying to develop the simple design of gas forced cooling large-capacity gas-insulated transformer. This paper deals with reseach and development of cooling and insulation technology of large-capacity gas-insulated transformer. Cooling characteristics of high pressure SF6 gas have been studied for cooling design. Turn-to-turn and section-to-section insulation of gas-insulated transformer winding have been studied for insulation design. Furthermore, development of 275kV 300MVA gas-insulated transformer is described.
