A novel topology of cross-connected sub-module(CCSM)with DC-fault clearance capability for modular multilevel converter is proposed and discussed. The CCSM containing 12 insulated gate bipolar transistors

12 anti-parallel diodes and 4 capacitors

can output 4

2

0 and -2 electrical level

respectively. The efficiency of CCSM is as high as that of clamp-double sub-modules

while more suitable for bulk power overhead line transmission. The modulation and voltage balancing strategy is also discussed. A simulation model is built in PSCAD/EMTDC

the simulation results proving the validity and the feasibility of the proposed topology and control strategy. This work is supported by State Grid Corporation of China(No. DW1600015).