| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for measuring a power for improving characteristics by reducing a measuring error in all power factor range including the case that the power factor is '-1' in addition to that the power factor is '1' and a power measuring apparatus using the method. SOLUTION: When a multiplying means 1 inputs two signals (v), (i) corresponding to AC voltage and AC current having equal basic frequency and outputs a signal corresponding to power represented by a product of the signals, a discriminating output means 2 separates an output signal of the multiplying means to positive and negative sides. Correcting means 3P, 3N individually multiply the signals separated by the output means by a predetermined coefficient for correcting the error of the multiplying means, outputs it. A combining means 4 combines the signals of the positive side and negative side multiplied by the coefficient by the correcting means corresponding to output polarities of the multiplying means.
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