GAS-INSULATED INSTRUMENT TRANSFORMER FOR POWER DEMANDMETER

PURPOSE:To achieve miniaturization and light weight and at the same time easy handling at the time of periodical inspection by providing an optical CT and an optical PT for detecting current and voltage of a three-phase primary conductor in a tank where an insulation gas is enclosed. CONSTITUTION:An instrument transformer consists of a tank 11, an insulation spacer 12, a reciprocating conductor 13 (13U-13W), a primary conductor 14 (14U-14W), an optical CT15 (15U-15W), and an optical PT16 (16U-16W). Also, a going path and a returning path of the conductor 13 is connected to a power supply side of each phase and load side main circuit conductors LU1-LW1 and LU2-LW2. Further, light is given through a light-emitting element in a secondary terminal box 18, an optical cable, and a light-receiving circuit for the optical CT15 and the optical PT16, the received light output is converted to electrical signal, and goes through arithmetic operation, thus enabling current and voltage transformation output corresponding to a size of a conduction current of the conductor 14 and a size of a voltage in reference to the ground to be generated.