Impact of Load Models on Elevated Neutral-to-Earth Voltage (NEV) in Distribution Systems

By uniformly grounding the distribution system and the customer's electrical system, neutral-to-earth voltage (NEV) can be moved from the distribution system to grounded objects in a building, like metal water pipes. The customer wiring may also be another possible cause of NEV. Furthermore, NEV is induced by load, leakage, and fault currents flowing through neutral or grounding connections. While ground rods and metallic water lines can channel leakage currents to the earth, every electrical system is subject to voltage-to-earth. Metallic structures connected to neutral or grounding systems will also be at the same NEV. The NEV/stray voltage generally occurs at low voltages and currents, so it is often undetectable. However, when people begin to experience shocks, it becomes a safety issue that, if not addressed, may have a severe impact. Using a backwards/forward sweep approach, this paper examines the effects of various factors on the neutral-to-earth voltage (NEV). An IEEE 13-bus distribution network demonstrates the proposed approach to evaluating NEVs. The results of the study are presented and analyzed. Matlab/Simulink software is used for all simulations.