Hybrid modular multilevel converter(MMC)has a broad prospect in long-distance

bulk-power high voltage direct current(HVDC)transmission with overhead lines. To analytically investigate the operating characteristics of converters

the dynamic and static analytical models of hybrid MMC are proposed. By solving the nonlinear equations regarding the internal electric quantities and control quantities though the static analytical model

the operating region of the converter under certain DC voltage and power is analytically obtained. The simulation results from electromagnetic model and the calculation results from the static analytical model regarding the internal quantities of the converter under different DC voltage levels are compared

which verifies the correctness of the static analytical model. A calculation method for the power operating zone of hybrid MMC is presented with multiple operating constraints considered

especially the constraint about feasible balancing of half-bridge sub-modules. The operating zones under different DC voltages are calculated

and the impact of various operating constraints and converter parameters like sub-module capacitor

arm inductance and full-bridge sub-module ratio on the operating zones are studied. The proposed analytical models provide the foundation for parameter design

steady-state analysis and small-signal modeling of hybrid MMC.