An AC/DC power flow algorithm considering controls state transformation

In the calculation of AC / DC power flow, how to consider the control mode of HVDC transmission system effectively is a problem that must be considered in power system planning and operation. In this paper, based on the principle of equivalent power and AC / DC system alternating decoupling solving, a power flow calculation program is presented. The main control modes of HVDC transmission system and their mutual conversion are considered in program. The DC lines in the case of EPRI-36 are modified as an example for calculation and analysis through the function of user program interface (UPI) of power system analysis software package (PSASP). The AC bus voltage of rectifier side and inverter side are regulated, and the corresponding operation state of the power flow is calculated. The results show that the AC / DC power flow algorithm proposed in this paper can be used to deal with the transformation of the DC operation mode which is caused by the change of operating conditions.