Analysis and mitigation of current unbalance due to induction in heavily loaded multicircuit power lines

High current unbalance may exist due to induction between circuits in a multicircuit right-of-way, especially when some of the circuits have heavy loads. This paper studies the problem and presents a mitigation technique to reduce the current unbalance. A brief analytical derivation is carried out to show the principle of the mitigation technique, which is based on transposition of the lines. The mitigation technique is then applied to an actual right-of-way with six circuits. Comparisons have been made between the untransposed circuits and the transposed circuits. It is shown that the unbalance level can be reduced significantly by appropriate phase transpositions based on the proposed principle. The mitigation technique presented in this paper can be applied to other right-of-way configurations to reduce current unbalances, therefore ensuring stable operation of the heavily loaded power lines.