摘要 |
A current differential pilot protective relay apparatus for multi-terminal high-voltage, three-phase alternating current transmission lines. The pilot protective relay system provides comparison, at each terminal of the transmission line, of the currents flowing on each phase of the three-phase transmission line at each terminal thereof. A novel scheme of summing the current-derived signals at one terminal reduces the number of receivers and transmitters necessary to send the local signal from each terminal to all of the other terminals. Instead, the current-derived signals are summed at one of the terminals and the sum signal is then transmitted to each of the other terminals.
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