VSC based DC grid power flow algorithm and AC/DC power flow algorithm

This paper attempts to establish a complete and unified DC Power Grid steady-state model, including the entire DC component such as VSC inverter, DC bus, DC line, DC-DC converters, etc. Based on steady-state model of DC Power Grid, a DC power flow algorithm is established which involves DC power flow equations construction, solution using Newton´s method. Then, this paper compares two AC/DC alternating iteration method (single-step alternating and sequential alternating), considers VSC constant DC power mode, studies the setting of the initial value, and presented a complete AC/DC power flow algorithm. Finally, the proposed algorithm is applied to CIGRE B4-58 DC power test system to show the validity of the algorithm. The convergence characteristics of the algorithm are also analyzed to verify the adaptive of the algorithm.