A new Wavelet based ground fault protection scheme for turbo generators

This paper proposes a protection scheme for turbo generators to detect stator ground faults in particular closer to neutral. The scheme considers total generated voltage of the machine and makes use of Wavelet Multi Resolution Analysis. A Fault Index is defined in terms of peak and valley values of the highest-level wavelet decomposition, which is compared with a threshold value to discriminate from other transients like sudden unbalance in load. The results of digital simulation are presented for different fault impedances and fault locations.