Alternator Stator Turn Fault Detection by Wing Technique

Stator turn fault (STF) is one of the major causes of alternator failure. If undetected at an early stage, these faults progress into severe failures. This can lead to irreversible alternator damage, unexpected outages, and significant operational losses. The Wing Technique (WT) has been previously reported for induction motors and transformers using current loci for turn fault detection. This paper for the first time applies WT through voltage loci including load currents and introduces it for alternators STF detection. It requires measuring three-phase stator currents and voltages under different operating conditions. This approach considers constructional imbalances, measurement errors, and unbalanced loads. The wing size indicates alternator loading, while its trajectory and area assess fault severity. Experimental validation is performed on a 10 kW, 400 V, 50 Hz, four-pole cylindrical alternator. The proposed technique enhances alternator reliability, efficiency, and safety. It enables predictive maintenance by determining the fault type and severity. Test results confirm the efficacy of the Wing Technique application.