IEEE Transactions on Power Apparatus and Systems · 1977 · 35 citations · 6 references
EngineeringComputer EngineeringElectrical EngineeringCircuit TheoryElectric MachinesPower ElectronicsCondition MonitoringFault DetectionGenerator OperationPower QualityProtection SystemsSynchronous MachinesFault AnalysisFault ProtectionFault Protection SystemsGenerator ProtectionGenerator Protection SystemsNegative Sequence CurrentsRelay ProtectionSynchronous Generator Operation
An on-line digital computer technique for the protection of a generator against internal asymmetrical faults is described in this paper. The proposed technique relies on the detection of a second harmonic component in the field current at the onset of a fault in the armature winding. Discrimination against external faults is achieved by monitoring the direction of the negative sequence power flow at the machine terminals. Tests have been conducted on a laboratory synchronous generator for various types of internal and external faults. Results show that the total time for internal fault detection and tripping is well within half a cycle of the 60 Hz signal. A simple extension to negative sequence relaying and loss of excitation relaying is proposed.
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