Effect of line modeling methods on neutral-to-earth voltage analysis of multi-grounded distribution feeders

Abstract

Accurate determination of neutral-to-earth voltages (NEV) in multi-grounded distribution circuits can be quite important, particularly in systems where loads are highly unbalanced or have considerable triplen harmonic current content. Some commercially-available and open source software are capable of representing distribution systems in adequate detail for performing NEV analysis. However, results can vary among programs depending on how the distribution line and associated grounding systems are modeled. This paper describes ways to model distribution lines and grounding systems to perform NEV analysis focusing on the earth return model. A simple test feeder is used to show how different distribution line and grounding system models affect NEV analysis.