MEASUREMENT APPARATUS OF GROUND CAPACITANCE IN ELECTRIC POWER SYSTEM

摘要

PROBLEM TO BE SOLVED: To accurately calculate a ground capacitance for deciding an operating point of a ground-fault relay.

SOLUTION: The measurement apparatus 11 is one for measuring a ground capacitance in an electric power system which continuously connects a limit resistor R1to a tertiary side of a grounding transformer 13 connected to a non-grounding electric circuit 12 and is equipped with a switch SW and a measuring resistor R2for measuring the ground capacitance of the non-grounding electric circuit 12 while being connected to the tertiary side of the grounding transformer 13 through a cable 15. The ground capacitance is calculated in taking an error portion in consideration, which is caused by a tertiary side circuit impedance of the grounding transformer 13 by an arithmetic process of a phase angle based on a three-phase batch grounding admittance Y00before a turn-on of the switch SW and a three-phase batch grounding admittance Y02after the turn-on of the switch SW.

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