Induced overvoltages on an AC-DC hybrid transmission system

Adding a DC circuit to an existing transmission line is one method of significantly increasing the power transfer capability of a transmission corridor. The resulting hybrid system has significant coupling between the AC and DC circuits, not only because of the proximity of the circuits, but also from the fact that they may share the same sending end or receiving end AC systems. The resultant interaction produces overvoltages on the DC system which can be somewhat higher than for a conventional DC scheme. This paper presents a study of these overvoltages.<
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