| 摘要 |
<p>PURPOSE:To facilitate the identification of a faulty portion of a protective relay, when supervisory signal data have exceeded the tolerances, by judging the object analog filters as defective. CONSTITUTION:Arithmetic circuits 22a and 22b for amplitude do arithmetic on the amplitude of high frequency supervisory signals for every channel and enter the results into comparators 23a and 23b, thereby checking whether the relative errors between the theoretical values of supervisory signals and the results are within the tolerance K1. An arithmetic circuit 24 for amplitude makes arithmetic on the amplitude of the vector sum of high frequency supervisory signals of two different channels, and checks whether an input to a comparator 25 is within the tolerance k2. AND circuits 36a, 36b are to detect the results of comparison by the comparators 23a, 23b, and 25 with the supervisory signal data in object channels when the results have exceeded the tolerances. When this detection is output, the analog filter in the corresponding channel is judged as defective. Thus, a defective portion can be identified easily.</p> |
