| 摘要 |
PURPOSE: An apparatus for metering instrument transformer error correction and a metering method are provided to accurately gauge actual used electric energy between a supplier and a consumer and compare metering errors before or after correction when an error is generated with a phase and 3 phase summing value when a metering error is generated due to a MOF(Metering Out Fit) malfunction. CONSTITUTION: A voltage and current measuring part(70) measures phase voltage and a phase current on a MOF(Metering Out Fit) secondary side. The voltage and current measuring part measures voltage using a PT(Potential transformer) at each phase and measures a current using a CT(Current Transformer) at each phase. A power calculation part(71) obtains the vector sum of the phase current before correction and calculates the current of a neutral conductor. Power before correction is calculated using the size and the phase of the phase current and the size and the phase of the phase voltage. A MOF failure determining part(72) determines the malfunction of the MOF using the size of the current of the neutral conductor and the phase of the neutral conductor. The malfunction of the PT or the CT is determined using the size and the phase of the phase current and the size and the phase of the neutral conductor. The PT or CT, in which the malfunction is generated, is displayed by the phase. An image power calculating part(73) calculates image power at the neutral conductor in the phase, in which the malfunction of the MOF is generated, using the size and the phase of the current of a phase which corresponds to a malfunctioning CT and the size and the phase of the neutral conductor. A power calculating part after correction(76) adds up the image power at the neutral conductor and the power before correction and calculates the power after correction.
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