The Early Detection of Stator Winding Shorted Turns in Permanent Magnet Three Phase Generators by Analysis of its Phase Voltages

The permanent magnet synchronous generator (PMSG) finds application in wind turbines and tidal stream generators. Those turbines, especially tidal stream devices are by definition, located in often remote and inaccessible locations which in turn makes maintenance issues a challenge. It is therefore necessary to employ condition monitoring methodologies to flag issues before they become critical or catastrophic. Stator winding inter-turn insulation breakdown is a particular issue in PMSGs. This paper proposes a methodology for the early detection of inter-turn short circuits in real time thus allowing remedial action to be taken before further winding problems develop. The methodology is based on the fact that inter-turn short circuits cause a phase voltage imbalance. The case study details the use of an Arduino microcontroller to detect the phase voltage imbalance and signal the result in binary format to a programmable controller (PLC). The study indicated that the methodology is both feasible and robust for detecting stator phase winding inter-turn short circuits.