Under the new situation where distribution network is developing into AC/DC hybrid distribution network

a three-phase unbalanced AC/DC power flow calculation algorithm considering interconnection from AC unbalanced networks with DC systems is proposed. Firstly

the three-phase steady-state power flow model of voltage source converter (VSC) is established. The power flow calculation equation of a three-phase VSC and DC distribution network is deduced in detail and the unbalanced system is compensated. Furthermore

considering different control methods and control strategies for multi-terminal DC system with voltage source converters (VSC-MTDC) in distribution network

a three-phase unbalanced AC/DC sequential iteration power flow calculation algorithm for distribution network is proposed. Based on the modularization idea

global iteration is not required

and the algorithm calculation could start from any direction of AC or DC side. As a result

the AC/DC power flow calculation is decoupled

and the over-limit variables can be corrected automatically. Finally

the simulation results on the modified IEEE 37-bus test feeder system demonstrate the effectiveness

rapidity and accuracy of the proposed algorithm.