Pourvali Souraki - Aliabad (Golestan) Power Plant Sana Co. Operation And Maintenance,Iran, Hassan.pourvali@gmail.com
Salman Amirkhani - Department Of Electrical Engineering, Aliabad katoul Branch, Islamic Azad University, Aliabad katoul, Iran, Amirkhan@aliabadiau .ac.ir
Masoud Radmehr - Young Researchers And Elite Club, Aliabad katoul Branch, Islamic Azad University, Aliabad katoul, Iran, Masoud_radmehr@yahoo .com

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.

Distribution systems, Ground resistance, voltage sag, voltage swell