A Hybrid Flexible Arc Suppression Method for Generator Stator Ground Faults Based on Slot Potential Analysis Unit

For generator stator ground faults, the active arc suppression method typically needs the large-capacity inverter, leading to huge size and high cost. Moreover, the existing compensated parameter calculation method based on coil potentials cannot suppress arc at the non-coil connection points. To address these limitations, a hybrid flexible arc suppression method is proposed in this paper. By combining with the arc suppression coil grounding method, only the third harmonic and partial fundamental currents need to be compensated by the active arc suppression device, which significantly reduces the inverter capacity requirement. Instead of the coil potential analysis unit, slot potential analysis unit is used to characterize the winding potential distribution. Analytical equations are formulated to precisely calculate the fundamental and the third-harmonic fault potentials across the entire windings. The calculation results are used to determine the compensated parameters, enabling reliable arc suppression at any fault position within the entire windings. Effectiveness of the proposed method is validated by simulation and experiment.