Unified Power Flow Calculation of AC-DC Hybrid Distribution Networks with Multiple VSC Converters

In AC/DC hybrid distribution networks, power flow calculation serves as a critical foundation for planning and operational control strategies. To achieve accurate and efficient power flow calculations in AC/DC hybrid distribution networks with multiple converter connections, this study proposes a unified power flow calculation method for AC/DC distribution networks incorporating multi-voltage source converter (VSC). First, the node types are classified into four categories based on whether they are directly connected to a converter. Next, a mathematical model of the voltage source converter is established, along with its power equations and fundamental control modes. Subsequently, the power equations for AC and DC system nodes are formulated, with a detailed classification and discussion of the equations for different node types. A unified power flow calculation model is developed for the AC/DC hybrid distribution networks, incorporating a two-stage method for rapid generation of the iterative matrix. Finally, by comparing power flow calculation results under different converter control modes, the algorithm’s speed, accuracy, and robustness are validated.