Improved Phase-coordinate Fixed-point Iterative Method Based on Equivalent Admittance Approximation for Power Flow Calculation in Three-phase Distribution Systems

This paper proposes an improved and unified fixed-point iterative method to solve the power flow problem in three-phase distribution systems by phase-coordinates. The proposed method which has definitude physical meaning in essence is to searching for the equivalent admittance approximations of the loads. And an improved decoupled method in topology for modeling the distribution equipment is given, which makes the models of distribution equipment easy to integrate into the proposed method. The solution characteristics analysis of the proposed method is given as well. The validity and effectiveness of the proposed method can be demonstrated by the numerical test systems.