Gauss-Newton Hybrid Power Flow Algorithm for AC-DC Distribution System

In this paper a hybrid power flow algorithm is proposed for multi-terminal AC-DC distribution system. Droop control is regularly used for multi-terminal system to coordinate the power output of each source, causing that the voltage of the slack bus is also needed to be calculated for power flow with an iteration-based method. So In this paper Newton method is adopted for DC distribution system, and Gaussian algorithm is used for AC distribution system, taking both advantages of less computational complexity and good convergence. Considering that the convergence of Newton method is sensitive to initial value, an initial value calculation method based on constant voltage control is proposed, to ensure the convergence of the algorithm when the initial value ranges with the droop control curve. Finally, the results are tested with a modified IEEE123 case, verifying the validity and correctness of the algorithm.