| 摘要 |
PURPOSE:To shorten response time of relay by executing logic operation with shorter operation period than a predetermined one upon judgement of no fault through a fault judging element and executing the logic operation with the predetermined period upon judgement of fault. CONSTITUTION:When both main judging elements M1, M2 make judgement of no fault, output signals m1, m2 are 0 and the register in a timer circuit T2 is reset with shorter operation period than a predetermined one thus setting an output signal tm2 to 0 and a trip signal to 0. when the signal m1 is 1, e.g. a fault in the electrical station at its end, the trip signal is brought immedately to 1 through an OR gate 1 thus interrupting a circuitbreaker CB. When the signal m2 is 1, e.g. a fault in the electrical station at the opposite end, a timer circuit T2 is started through an event counter CO and the signal tm2 is brought to 1 upon finish of predetermined count while the trip signal is brought to 1 through the OR gate 1 thus interrupting the circuitbreaker CB. By such arrangement, response time of protective relay is shortened. |
