Stator Turn-to-turn Fault Detection of Synchronous Generator Using Total Harmonic Distortion (thd) Analyzing of Magnetic Flux Linkage

Diagnostics of synchronous generator turn-to-turn faults can be accomplished by analyzing the anomalies of machine local variable such as magnetic flux linkage. On the other hand, because current transformers and voltage transformers are usually installed in the machine for different purposes as default, the monitoring schemes that depend on the study of these inputs have become a topic of interest. As a consequence, in the last two decades, a variety of methods have been proposed based only on the global external variable (such as stator current and voltage). It must be noted that the global external variable analysis techniques are not capable of detecting all of the potential faults in electrical machines and some researches, including this work, aim to transfer a part of the global external variables analysis knowledge to techniques that monitor the signatures produced by the fault to the electromagnetic flux signals (local variable). Hence, this contribution deals with the analysis of the stator turn-to-turn short circuit fault of salient-pole synchronous generator. In this paper, a fault indicator based on harmonic analysis of the magnetic flux linkage is investigated. Experimental results derived from a 4-pole, 380V, 1500 rpm, 50 Hz, 50 KVA, 3-phase salient-pole synchronous generator, show that the proposed method is useful and effective. Keywords– Synchronous generator, inter-turn fault, magnetic flux linkage, harmonic analysis