An unified iterative algorithm for load flow analysis of power system including wind farms

Abstract

This paper presents a new power flow (PF) technique for distribution system including wind farms (WFs) with asynchronous generators (AGs) represented by RXv bus model using an unified iterative algorithm. With RXv bus model, AGs are supposed as RX load buses with their equivalent impedances and v is wind speed. In addition, it is assumed that wind speed is a known variable which combined with the AGs' impedance to become the RXv model. The paper proposes a highly efficient and accurate method which combines the slip variables corresponding to the AGs with the nodal voltage magnitudes and angles of the network in a single frame-of-reference for a unified iterative solution. The method retains Newton Raphson (NR) quadratic convergence characteristics. By considering characteristics of AGs, the RXv bus model is more suitable. To validate the proposed model, the modified IEEE 30-bus system with two connected WFs is used to represent wind generators in power flow analysis. Calculated results of load flow analysis program show that the proposed model and the unified calculating method are feasible and accurate.