| 摘要 |
PURPOSE:To make it possible to calculate an impedance square value having no frequency error, by performing predetermined operation by using current and voltage data which are sampled at a predetermined cycle and mutually set at 90 deg. intervals. CONSTITUTION:When Ai Ai-1, Ai-1 Ai-2 and phi=thetak are set in the frequency characteristic of a reactive component power formula Ai.Bi-1-Bi.Ai-1=Ap.Bp. Sinphi.sin(thetak), Ai-1.Bi-1-Bi.Ai-2=Ap.Bpsin(thetak).sin(thetak) is formed. Herein, when Ai=Bi is set to fix phase relation, x=Ai-1<2>-Ai.Ai-2=A<2>psin<2>(thetak), y=Bi-2<2>-Bi. Bi-2=B<2>Psin<2>(thetak) are obtained. From this, y/x=(Bi-1<2>-Bi. Bi-2)/(Ai-1<2>-Ai. Ai-2)=B<2>p.sin<2>(thetak)/A<2>psin<2>(thetak)=z<2> are formed and the judgement of a level or the measurement of a ratio of x and y can be performed by y<x.k<2> or y>x. K<2> (wherein K is an integer constant).
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