| 摘要 |
PURPOSE:To obtain a digital type protective relay which can be applied in a frequency range wider than that of the prior art. CONSTITUTION:The digital type protecting relay comprises a plurality of digital filter processors 11, 21 of l/ (1-Z-2<-2n>) (n is natural number), a plurality of wide band filter processors 12, 22 of (1 + 0.25<-6n>)/(1-0.25), a plurality of amplitude value calculating processors 13, 23 of eta1<2>=Im-3<2>-Im.Im-6 and eta2<2>= Jm-6<2>- Jm.Jn-12, a maximum amplitude value detector 20 for selectively outputting larger one of a plurality of square values eta1<2>, eta2<2> of amplitude values, and a relay discriminator 14 for comparing the maximum amplitude value eta<2> with a settled value. |
