Features and capabilities of grounding systems in modern power systems
University of New Brunswick
Ground currents and ground potential rise are major causes for thermal damages, degraded performance, poor power quality, and safety risks in power system equipment (generating units, transformers, home appliances, substations, etc.). Transient changes in ground currents and potentials are typically triggered by ground faults (single-line-to-ground and double-line-to-ground faults), as well as steady-state high-harmonic current-flows to system grounding. In many cases, the rapid rise in ground potential during a ground fault, can lead to transient over-voltages and/or phase inversion, which pose significant challenges to the operation of various power system equipment. Adverse impacts of high ground currents and potentials can be reduced by an adequate design of grounding systems. This thesis provides detailed time-domain models of grounding system designs, along with their recommended settings that can ensure stable operation of power system equipment. In addition, this thesis presents performance and comparison results for grounding system designs during and post ground faults.