| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an abnormality sign determining device for electric quantity data, having high sensitivity and reliability obtained by calculating a coefficient of correlation on each pair of a large amount of input electric quantity data input into a plurality of protective control measuring instruments and determining an abnormality sign on the basis of the coefficient of the correlation. <P>SOLUTION: The electric quantity at the same point in a power system is captured in three or more digital protective control measuring instruments 3<SB>-1</SB>to 3<SB>-N</SB>, and a Pearson's product-moment correlation coefficient is used to determine an abnormality sign in instrument transformers (VT, CT) 4<SB>-1</SB>to 4<SB>-N</SB>or an abnormality sign in an analog circuit provided to the protective control measuring instruments 3<SB>-1</SB>to 3<SB>-N</SB>. <P>COPYRIGHT: (C)2010,JPO&INPIT |
