Challenges of an AC Line and a Parallel Mono-Polar DC Line Separated on a Same Right of Way

Ground resistivity, zero sequence currents, frequency response, phase domain modelling The purpose of this research is to look at the reason of significant zero sequence transients in ac lines caused by transients in a surrounding earth return dc circuit. A qualitative reasoning as well as a quantitative parametric examination are offered. The results reveal that even for relatively close lines, very significant transients can occur. Furthermore, transients appear only when non-zero ground resistivity is incorporated in the model. Different ground resistivities, earthing resistances, and the presence or absence of ground wires are also investigated. The document should be of interest to utilities that operate alternating current and direct current lines on the same right of way.