Distinguishing motor starts from short circuits through phase-angle measurements.
Yenchek MR; Cawley JC; Brautigam AL; Peterson JS
IEEE Trans Ind Appl 2002 Jan/Feb; 38(1):195-202
The National Institute for Occupational Safety and Health investigated how the starting of induction motors may cause nuisance tripping of short-circuit protection on coal mine power systems. This research had a dual purpose: 1) to identify how motor-start waveforms differ from those for short circuits and 2) to devise a method to provide short-circuit protection without intentional time delays to account for motor starts. This technology will help ensure that surface temperatures of energized electrical apparatus will not exceed gas or dust ignition thresholds when short circuits occur.
Coal-mining; Mining-industry; Electrical-safety; Electrical-hazards; Underground-mining; Mining-equipment; Electrical-equipment; Electrical-properties; Electronic-circuits; Voltage-regulation;
Author Keywords: Longwalls; mining; motor; phase angle; short circuit
National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory, P.O. Box 18070, Pittsburgh, PA 15236-0070
IEEE Transactions on Industry Applications