Analysis of Induced Voltages on the Sheath of Single-Circuit Underground Power Lines - Part II: With Phases Transposition

This paper investigates the induced voltages that impact the sheath of transposed single-circuit underground transmission lines. The study mainly focuses on three-phase transmission lines’ triangular and flat formations. The investigation hones in on two pivotal aspects: firstly, the calculation of induced voltages, and secondly, the comparison of current imbalances within an underground sub-transmission system. The results indicate that for the triangular formation, phases transposition proves unnecessary, as the induced voltages on the sheath exhibit are the same across all phases. Moreover, the values are the same as those from the triangular formation without phases transposition. On the other hand, for flat formation with phases transposition, the induced voltage in the extreme phases has the same value as the center phase, where the maximum value is generated in the extreme phases. Furthermore, the maximum value of induced voltage generated by continuous cross-bonding is higher than that generated by sectionalized cross-bonding per almost 2 V.