Induced Stray Voltages from Transmission Lines

Stray voltages are inherent in four-wire multigrounded distribution systems. At the customer´s premise, these voltages result from the interaction of multiple parameters of the primary and secondary neutral systems. The causes of stray voltages typically include large unbalanced loads in the neutral system, high neutral impedance, and lack of equipotential grounding at the customer´s premise. Non-conventional sources of stray voltages may also exist. These sources may consist of large triplen harmonic currents on the neutral system or induction from a nearby transmission line. This paper describes a case study involving induced stray voltages on a single phase distribution line running parallel with a 500 kV transmission line