Ground Fault Protection of Synchronous Generators with Frequency-Selective Grounding

• Published in: 2022 IEEE Industry Applications Society Annual Meeting (IAS) pp. 1 - 8
• Main Authors: Saleh, S., Jewett, D., Meng, J., Valdes, M., Ahshan, R., Panetta, S., Mardegan, C.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 09.10.2022
• Subjects: Fault protection; Frequency-selective grounding; ground fault protection of synchronous generators; Grounding; Industry applications; Loading; power system faults; Protective relaying; Solids; Synchronous generators
• ISSN: 2576-702X
• DOI: 10.1109/IAS54023.2022.9939677

This paper experimentally evaluates responses of ground fault protection for synchronous generators, which are grounded using frequency-selective grounding. Frequency-selective grounding is designed to provide a low ground impedance path (similar to solid grounding) for high frequency zero-sequence current components. This grounding system also provides an impedance similar to a low-resistance grounding for low frequency zero-sequence current components. The frequency-dependent equivalent impedance of frequency-selective grounding can affect ground potential and current, which are typically used as inputs for ground fault protective relays. Effects of frequency-selective grounding on ground fault protection are experimentally evaluated using a 7.5 kVA synchronous generator. Experimental tests are conducted for different implementations of ground fault protection, when responding to fault and non-fault events. Evaluation results detailed in this paper demonstrate the negligible effects of frequency-selective grounding on responses of different ground fault protection relays.