| 摘要 |
PROBLEM TO BE SOLVED: To display a power factor of each phase by using a phase voltage basis obtained from a line voltage basis in the measurement of a three-phase three-line electric power line system using a two-power meter method in order to make a phase relation between a voltage and a current understood more easily, and to surely detect incorrect connection. SOLUTION: A method for detecting a connection state is provided in which a phase differenceθ1 of the phase current I1 of a first phase and a phase differenceθ2 of the phase current I2 of a third phase with an inter-line voltage U1 as a refrence are converted into phase differencesα1,α2, respectively, on the basis of the phase voltage, and then a power factor PF1(cos(α1)) of the first phase and a power factor PF2(cos(α2)) of the third phase are displayed, and an abnormal state is displayed whenα1,α2>0°is satisfied. COPYRIGHT: (C)2010,JPO&INPIT
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