TESTING METHOD OF INSULATION OF SUBSTATION HAVING GAS-INSULATED SWITCHING DEVICE APPLIED

摘要

PURPOSE:To prevent occurrence of reflection by a method wherein, after a substation constructed of a gas-insulated switching device is completed, breakers and disconnectors are put in appropriate switching states, the provision of a long branch circuit is thereby eliminated and a lightning impulse voltage is impressed on one end, while a resistance being equal substantially to a surge impedance of a bus of the switching device is provided at a terminal. CONSTITUTION:A substation is divided into several blocks so that no large reflection occurs, and a voltage of the same crest value is impressed on each block. For this purpose, first breakers 18, 19, 32 and 60 are closed and disconnectors 40, 41, 43, 44 and 45 are opened. Then, a high-voltage resistor 80 of which the resistance is equal to a surge impedance of a bus 24 is connected to the ground on the air side of a bushing 4, while a lightning impulse voltage generator 90 is provided on the air side of a bushing 1. If a metallic extraneous substance sticks on the surface of an insulating spacer or the like and this causes inversion of the polarity of a lightning impulse voltage and lowering of a insulating performance, the breakers 18, 19, 32 and 60 are opened, while disconnectors 46, 51, 41, 43 and 44 are opened, and thereby impression of the lightning impulse voltage on the main bus 30 side is enabled.