摘要 |
<p>1531430 Detecting faults on polyphase lines WESTINGHOUSE ELECTRIC CORP 31 Dec 1975 [7 Feb 1975] 53370/75 Heading H2K A three-phase protective system detects earth faults by monitoring a first signal representing the zero-sequence current at one end of a line and phase-to-phase faults by monitoring a second signal representing the difference of any two of the phase currents, each signal being compared in phase with a corresponding signal from the other end of the line to determine whether the fault is internal or external to the line. The details of the monitoring and phase-comparing systems are as described in Specification 1,449,682.</p> |