| 摘要 |
PROBLEM TO BE SOLVED: To obtain a PCM current differential relay realizing highly accurate protection for transmission system by matching the sampling timing of transmission line current PCM signal without being subjected to restrictive conditions on the propagation lag time of the transmission line thereby comparing the transmission line current PCM signal of a host unit accurately with that from a counterpart unit. SOLUTION: The PCM current differential relay 11-A, 11-B comprises a section 22-A, 22-B for generating a sampling clock synchronized in phase with a transmission line current, an analog/digital converting section 21-A, 21-B for sampling the transmission line current with the sampling clock and converting it into a PCM signal, a section 23-A, 23-B for transmitting the PCM signal in a frame structure synchronized in phase with the transmission line current to a counterpart unit, and a processing section 24-A, 24-B for comparing a PCM signal received from the counterpart unit with that of its own unit and detecting a transmission line fault. |
