To reduce development costs by connecting general-purpose computers together via LAN, and synchronizing the times at which processings are made by a computer for input/output processing with times processed by a computer for protection relay calculation.
When a computer 30 for input/output processing as an input/ output processing terminal for transmission line protection outputs system information to LAN 50, a general-purpose computer 40 for protection relay calculation is fed with the system information from the LAN 50 and performs relay operation. If an circuit breaker in the power system needs to be opened, the computer for protection relay calculation outputs a trip signal to the LAN 50. At this time, since the timing for sampling the respective amounts of information on the power system needs to be the same, a time-of-day synchronizing means is constituted, using the transfer control parts 64 and 69 of the computers, and the time-of-day synchronization control between the computers 30 and 40 is carried out by software processing.
ITO KENJI
NAKAYAMA HIDEO
INOUE KAZUSHIGE
SHIMANO SHINJI
KANSAI ELECTRIC POWER CO
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