An AC/DC alternating power flow algorithm based on forward-backward sweep method for the distribution network with SST

Solid state transformer(SST) is an energy flow operation device of Energy Internet, in order to research the operation of SST and its effect on the power flow calculation in distribution network, an AC/DC alternating power flow algorithm based on forward-backward sweep method(FBSM) for the distribution network with SST(DNWS) is proposed. In this paper, the steady-state model and control methods of SST are analyzed in detail. Then, the DNWS is partitioned into three parts: AC system 1 connected to SST, SST and AC system 2 connected to SST according to its structural features. In this network, the overall distribution of power flow is calculated by the algorithm in which the DC power flow calculation is nested in the AC power flow calculation that is based on FBSM. Elaborating the ability of power flow regulation of SST and SST's control methods, the algorithm can calculate the control variables and state variables of SST and can take into account the SST loss more accurately. Finally, the validity and correctness of the algorithm are verified by the example results.