A new method for OPF combining interior point method and filled function method

Due to the nonconvexity of optimal power flow (OPF) problem, the methods based on the Karush-Kuhn-Tucker necessary conditions can only guarantee to get a local minimal solution. This paper presents a new method by combining primal-dual interior point method (PDIPM) and filled function method (FFM), which can converge to a global minimum of the OPF problem. The proposed method includes two stages in each iteration. In the first stage, a minimum of the OPF problem will be obtained by PDIPM and if it traps at a local minimum, the second stage by FFM can help to escape from the previously local minimum and provide a better initial point for the first stage. By repeating the two stages, a global minimum of the OPF problem can be obtained finally. The numerical results show that the proposed method can escape from local minima and converge to the global optimal solution effectively.