With the steady development of voltage source converter (VSC) and parallel DC grid based on VSC

the future power grid may become hybrid AC/DC networks containing multi-DC buses

multi-DC lines and multi-DC loads. The steady-state model and control mode of VSC are analyzed

and the power flow model of AC/DC networks containing DC grid based on VSC is derived. Then the power flow solution for DC grid with different control modes is studied prior to proposing a generalized alternating iterative power flow algorithm. This algorithm decouples the AC grid and the DC grid according to different control modes of the VSC station. In each iteration of the algorithm

AC grid iteration follows the DC grid iteration. The algorithm will not stop calculating AC and DC alternatively until the DC grid

VSC station and AC grid are all convergent. Diverse control modes of DC grid

the constraint of variables and the change of VSC control mode are taken into consideration. Finally

with the modified IEEE 57-bus AC/DC networks

several simulation results clearly verified the feasibility and effectiveness of the proposed algorithm.