A novel load flow model for distribution systems based on current injections

With the wide application of distributed generators (DGs) and other distributed energy sources (DERs) being integrated to distribution systems, the DGs can be described as different load flow models. Traditional load flow calculation model might have difficulty in getting the load flow results fast and accurately. A novel model to solve the load flow problem is proposed in this paper, especially for distribution systems with DGs. Based on the analysis of DGs' characteristics, the buses are classified into 5 types: slack bus, PQ bus, interconnecting (IC) bus, PV bus and PI bus. Using the current injection equations written in rectangular coordinates, different variables (I, θ, V, α, I
x
, Q) are introduced into the proposed model for different bus types. The computational results validate the effectiveness and accuracy of the proposed method, when compared to the traditional load flow model in terms of power injections.