PURPOSE: To provide a transformation-of-electrical-energy installation whose designing and manufacturing time is reduced by simplifying the shape of a gas-insulated bus, which reduces the length of a connection bus and which is provided with an excellent effect to enhance a dealing property in the accident of a gas-insulated switchgear by making the transformation-of-electrical- energy installation small anal by ensuring the proper separating interval between transformers.

CONSTITUTION: A plurality of transformers 1 are arranged by keeping a definite distance. Every transformer 1 is connected to main buses 10 by a gas-insulated switchgear 11. A cooler 2 and a conservator 3 are installed at the upper part of every transformer 1. A connection part 5 is installed at the side face of every transformer 1, and the gas-insulated switchgear 11 is connected to the connection part 5. The gas-insulated switchgear 11 is constituted of a gas- insulated bus 6 which is connected to the connection part 5, of a lightning arrester 7, of a gas breaker 8 and of disconnectors 9, and it is connected to the main buses 10 at the disconnectors 9. Every transformer 1 is arranged in the earth or to be lower than the surface level of the earth.