Analysis of voltage profile in multi-grounded four-wire power distribution systems considering the ground resistance

Most power distribution systems in North America employ a four-wire multi-grounded neutral design. This paper has explained the inherent characteristics of multi-grounded three-phase four-wire distribution systems under unbalanced situations. As a result, the mechanism of voltage swell and voltage sag in MGN feeders becomes difficult to understand. Thepurpose of this letter is to reveal and quantify all factors that contribute to voltage swell and voltage sag in multi-grounded neutral system. Sags and swells are the most common types of power quality disturbances. The results are expected to help utility engineers to understand the impact of MGN on distribution system operations.