Temporary Overvoltage and GPR Characteristics of Distribution Feeders With Multigrounded Neutral

Three-phase four-wire multigrounded neutral (MGN) is the preferred distribution line configuration in North America. Its performance characteristics, such as temporary overvoltage (voltage swell) and ground potential rise (GPR), are difficult to understand and assess due to the presence of a neutral conductor and the conductor´s multiple grounding nature. The characteristics are further affected by unique parameters, such as grounding intervals and the coupling between neutral and phase conductors. This paper conducts analytical studies on the phenomena of temporary overvoltage and GPR associated with MGN configurations. The purpose is to reveal the mechanisms leading to the phenomena and their contributing factors. Approximate formulae are derived to quantify the impact of various factors. The findings are confirmed by the simulation results.