| 摘要 |
PROBLEM TO BE SOLVED: To provide a measuring device and method capable of directly measuring, even in case of a change in frequency of a power system that is a measuring object, the voltage, effective value of current, active power, reactive power and frequency of the power system with a minimized error from sampling data without performing a correction operation. SOLUTION: This device comprises an anti-aliasing filter, a sample holding means for sampling and holding the waveform of voltage in an AC signal every predetermined period, an analog/digital conversion means for converting analog data to digital data, a basic wave extraction means for extracting a basic wave component around a commercial frequency, a voltage value temporary storage means for temporarily storing voltage values up to 4 samples before, and a voltage value computing means for substituting the voltage values up to 4 samples before to an arithmetic expression. The effective value of the voltage that is a measuring object is computed with the following arithmetic expression. COPYRIGHT: (C)2005,JPO&NCIPI
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