Off-Line Detection of Static Eccentricity in Salient-Pole Synchronous Machines

Since synchronous generators are the main electric power producing devices, it is crucial to guarantee their safe and reliable operation. However, faults may appear and inflict great losses. So, condition monitoring of such machines is critical to avoid unscheduled stops and unplanned maintenance. This paper works towards that direction. The authors are proposing a new off-line method to reliably detect the static eccentricity fault in synchronous salient pole electrical machines. The method is based on the monitoring of all three phase currents of the machine during locked rotor at three different rotor positions. A pseudo zero-sequence current is then calculated, the frequency spectrum of which can reveal reliable indicators to detect this fault. The proposed method has been tested experimentally with success, while the results indicate that it is possible to estimate the fault level severity.