Monopolar operation of Modular Multilevel DC-DC Converter Based Hybrid Bipolar HVDC Links

Abstract

Modular multilevel converter has been identified as an effective solution for bidirectional power flow between line commutated converter (LCC) and voltage source converter (VSC) based high voltage dc (HVdc) links which has encouraged multi-terminal bipolar operation in HVdc transmission. This paper introduces topological modification and novel philosophy of operation for an existing modular dc-dc converter topology for operation between monopolar VSC and bipolar LCC based dc links. The effectiveness of the philosophy is demonstrated in multi-terminal operation by simulation in MATLAB/Simulink platform.