A Hybrid VSC-HVDC System based on Modular Multilevel Converter and Alternate Arm Converter

The interoperability challenges of emerging modular voltage source converter (VSC) topologies HVDC systems should be addressed along with rapid transformation of power systems driven by the need for more interconnected networks. This paper derives a hybrid VSC-HVDC model and demonstrates the interoperability of emerging alternate arm converter (AAC) with the state-of-the-art modular multilevel converter (MMC) in HVDC systems. The study provides primary steps towards detailed analysis of AAC interoperability in complex dc grid configurations. A detailed set of results based on the 800 MVA hybrid VSC-HVDC system demonstrate the interoperability performance of the AAC under different operating scenarios and verify associated control functions.