| 摘要 |
<P>PROBLEM TO BE SOLVED: To perform sampling synchronization of a PCM current differential relay with accuracy at high speed when transmission error is restored. <P>SOLUTION: Two or more PCM current differential relays 16A-16C are provided in accordance with two or more terminals, which constitute a protecting sections of a power cable 11. In each PCM current differential relay, a current of the power cable at self terminal is subjected to sampling and converted to a PCM signal, and each PCM signal is transmitted and compared with each other through the transmission line so that a failure in the protecting section is detected in the PCM current differential relay. The sampling synchronization operation of current with another PCM current differential relay at another terminal can be performed by one PCM current differential relay, which is provided in accordance with one terminal. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
