An Approximate Power Flow Method to Deal with the Non-convergence Problem of Power Flow Calculation

A new concept of approximate power flow (APF) is proposed in this paper, aiming to help deal with the non-convergence problem of power flow calculation. In the approximate power flow model, active and reactive power decoupling strategy is adopted, and a branch model with virtual midpoint is the key foundation of the whole research. Based on the branch model, the approximate power flow equation is constructed and its iterative solving method with good characteristics of convergence is also introduced. Active and reactive power automatic adjustment measures are also used to improve the algorithm robustness. The effectiveness and feasibility of this approximate power flow model is proved by the error and robustness analysis for practical examples. The APF program has been developed based on the proposed method, and can be applied to the actual large-scale power grid.