Research on the application of SLCC DC transmission technology in high-voltage DC transmission projects

High-voltage direct current (HVDC) transmission technology has become the core means for long-distance and large-capacity power transmission due to its advantages such as large transmission capacity, low loss, and strong stability. Traditional HVDC technology based on line-commutated converters (LCC) has inherent defects such as the limitation of the short-circuit capacity of the receiving-end system and the inability to achieve multi-terminal interconnection. Although the flexible DC technology based on voltage-source converters (VSC) has the capability to connect renewable energy, it is constrained by component costs and technical maturity. As a new converter topology integrating the technical advantages of LCC and VSC, SLCC (Half-Bridge Modular Multilevel Converter) enhances system flexibility and reduces fault current levels through optimized control strategies, while maintaining high engineering economy. This paper aims to explore the operational characteristics and engineering application feasibility of SLCC technology in HVDC projects.