Fault Calculation for Modular Multilevel Matrix Converter Considering Control Characteristics

The development of offshore wind power presents new challenges and opportunities for the integration into the power system, with the Frequency Division Transmission System (FFTS) gaining significant attention as an efficient grid connection technology. By reducing the transmission frequency, it is possible to decrease the line reactance and charging power, thus increasing the transmission capacity of the lines. This represents one of the highly promising approaches for integrating offshore wind power. However, challenges exist for the Frequency Division Offshore Transmission System, particularly during fault conditions, necessitating targeted research into fault current limiting schemes and adjustments to protection parameters to ensure the safe and stable operation of the system. Current research predominantly focuses on the operational control of the Modular Multilevel Converter (M3C) itself, with relatively scant investigation into the transient fault characteristics at the sending and receiving ends of M3C. Addressing this issue, a literature proposes a fault transient analysis method considering control characteristics, validated in PSCAD/EMTDC. Such studies hold significant theoretical and engineering value in addressing issues related to equipment parameter design, control strategies, and protection configuration selection.