| 摘要 |
PROBLEM TO BE SOLVED: To surely obtain protection coordination among power generating facilities by lowering the costs of the facilities and connecting the facilities in series, by collectively protecting the facilities from a main substation when overcurrents occur in system connecting lines by transmitting information on failures and opening/closing states to the main substation from I/O interfaces. SOLUTION: In linking devices 21-2N, ground-fault protection is performed by distinguishing local ground faults and system ground faults from each other by means of switches 4 and 5 and ground-fault directional relays 6 and 8. For protecting the devices 21-2N when ground- faults occur, protection coordination is obtained among the devices 21-2N in such a way that the occurrence of an overcurrent is detected by means of an overcurrent relay 9 and, when the relay 9 detects the occurrence, the operations of the switches 4 and 5 are locked and collective protection is performed from a main substation 1. In order to obtain the protection coordination when the overcurrent occurs, a function of transmitting information on failures and opening/closing states to a remote supervisory and controlling facility and another function of controlling the opening/closing of the switches 4 and 5 following opening/closing commands from the remote supervisory and controlling facility are provided by installing an I/O interface 10 to each linking device 2. The power supply for the functions is secured from the system connecting lines in the linking devices 21-2N through a transformer 11 for control. |
