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 transmissi on corridor. The resulting hybrid system has significant coupling betw een the ac and dc circuits, not only because bf the proximity of the c ircuits, but also from the fact that they may share the same sending e nd or receiving end ac systems. The resultant interaction produces ove rvoltages on the dc system which can be somewhat higher than for a con ventional dc scheme, This paper presents a study of these overvoltages .