| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a protective relay capable of accurately responding to a wide detection range of a current transformer, while controlling its manufacturing cost. <P>SOLUTION: A plurality of input taps are provided on an auxiliary current transformer 5. An A/D converter 27, a plurality of input ranges of which are changeable, is provided on a circuit 6 connected electrically to the secondary side of the auxiliary current transformer 5. The manufacturing cost can be controlled without providing circuits of a plurality of systems or without increasing resolutions of the A/D converter 27 unnecessarily. The protective relay can accurately respond to the wide detection range of the current transformer 3 by the multiplication of the kinds of winding ratio of the auxiliary current transformer 5 and the kinds of the input ranges of the A/D converter 27. <P>COPYRIGHT: (C)2008,JPO&INPIT |
