Faults analysis for combined MMC and AAC with practical HVDC grid

Modular Multilevel Converter (M²C) and Alternate-Arm Converter (A²C) are the prevalent types of voltage-source converter (VSC) topology for HVDC applications. A novel model of the VSC using combined M²C and A²C is proposed in this paper. This new model is applied to practical HVDC links between France and Spain, which has 320 kV, 2 GW by inserting M²C in sending end and A²C in receiving end. The combination models are interconnecting with two 400 kV high-voltage AC grids. This paper considers the interaction of the combined models with all types of faults analyses. DC Line-to-Line and DC Line-to-Ground Faults are carried out. Symmetrical and unsymmetrical faults are carried out involves all types of faults. Single-phase, two phase and three phase to ground faults at the sending side of the proposed models are tested one by one.