| As a new stage in the development of power grid, the AC/DC hybrid connected power grid is characterized by multi-type DC participation and large-scale AC/DC interconnection. However, the applicability of the unified iteration and alternating iteration algorithms for power flow calculation has not been deeply analyzed. Therefore, based on an AC/DC hybrid connected power grid with multi-type DC, the calculation performance of the two algorithms is compared and studied. The power flow model of the AC/DC hybrid connected power grid with conventional DC, flexible DC, and hybrid DC is derived, and correspon-ding unified iteration and alternating iteration algorithms are proposed. The effectiveness of the power flow model and the accuracy of power flow algorithms are verified by the data of three AC/DC hybrid connected power grid test systems and the actual system of China Southern Power Grid. The convergence performance and calculation speed of the two algorithms are compared and analyzed in combination with the factors such as system load level, system strength, and DC embedding scale. The research results show that during the calculative progress of large-scale AC/DC hybrid connected power grid with multi-type DC, the unified iteration algorithm has higher computational efficiency than that of the alternating iteration algorithm. |
