DIGITAL TYPE PROTECTIVE RELAY

摘要

PROBLEM TO BE SOLVED: To provide a digital type protective relay of which the cost is reduced and the reliability is improved by simplifying circuit configuration by performing sampling frequency switching and restart processing in a combination manner, thereby eliminating the need to independently provide a protective relay output lock circuit or a time cooperation circuit.SOLUTION: The digital type protective relay includes: a system frequency detection part 5 for detecting that a system frequency of a power system subjected to protection is switched; a sampling frequency switching circuit 6 which switches a sampling frequency in accordance with the system frequency detected by the system frequency detection part 5; a CPU unit 14 including a plurality of CPU boards; and a multi-restart part 7 which performs collective restart processing of all the CPU boards included in the CPU unit 14 when the sampling frequency switching circuit 6 switches the sampling frequency.SELECTED DRAWING: Figure 1