Adaptive 100% Injection-Based Generator Stator Ground Fault Protection With Real-Time Fault Location Capability

The paper presents a novel adaptive stator ground fault protection scheme with fault location capability for high-impedance grounded synchronous generators. The protection scheme uses already available neutral grounding signals in the existing subharmonic injection protection to obtain a Kalman adaptive filter (KAF) for real-time stator insulation parameter estimation. The KAF estimator yields a method of continuous tracking of stator insulation condition during healthy operations. This information is then used for real-time stator ground fault detection as well as fault location. The effectiveness of the proposed method is verified using extensive experiments performed on a lab-scale unit-connected generating station.