| 摘要 |
PROBLEM TO BE SOLVED: To provide a digital protective relay device that does not cause a circuit breaker to malfunction even when a contact failure occurs in a circuit breaker pallet switch.SOLUTION: A digital protection control device includes a pallet switch open phase detection means 7 that detects the open-phase state of a power transmission line based on the open/closed state of the pallet switch 5 of a circuit breaker 4, an analog input means 10 that digitally converts current data, a current amplitude value calculation means 11 that calculates a current amplitude value from current data, a load flow detection means 12 that determines whether a current amplitude value is equal to or lower than a predetermined value, an analog open phase detection means 13 that detects the open-phase state of a power transmission line, a combination determination means 14 that determines the presence or absence of an open-phase state, and an external output means 15 that outputs an open phase interruption command to the circuit breaker 4. |
