Probabilistic Assessment of the VSC-HVDC Contribution in Voltage Stability Applied to a Hybrid DC-Multi-Infeed Scenario

The still-growing penetration of HVDC links interfaced by Line Commutated Converters (LCC) raises questions about how their operational characteristics will affect the system reliability, particularly in situations of converters stations nearby. In those cases, interaction phenomena tend to reduce voltage and system stability, mainly concurrent commutation failure in the inverters stations caused by near faults in the AC side, which may lead to unwanted interruption of operation. Therefore, techniques to mitigate adverse interactions need to be studied. In this context, this paper presents a commutation failure mitigation technique analysis, in which a VSC-HVDC provides reactive support and direct enhancement in voltage stability in a multi-infeed with two LCC-HVDC links. Besides, this work also presents a statistical study between two methods of VSC-HVDC current control strategies and their efficiency in mitigating commutation failure.