| 摘要 |
PROBLEM TO BE SOLVED: To prevent a relay device from answering needlessly, even in a case where a current transformer for a meter caused saturation, when an external accident occurs in the non-power terminal of a transformer. SOLUTION: In a transformer protective relay device 1A equipped with a ratio differential relay 11 introducing the AC current of each terminal of a transformer and outputting a protection command at internal accident time of the transformer, a first means 13 which introduces the AC current of the non-power terminal of the transformer and computes the amplitude value of the AC current of the non-power terminal or the quantity proportional to it, a second means 14 which outputs a signal when the quantity computed with the first means 13 fulfills the specified conditions, and a control means 12 which controls the protection command output of the ratio differential relay 11, using the output signal of the second means 14 are installed. |
