Linear Three-Phase Power Flow for Unbalanced Active Distribution Networks with PV Nodes

High penetration of distributed renewable energy promotes the development of an active distribution network (ADN). The power flow calculation is the basis of ADN analysis. This paper proposes an approximate linear three-phase power flow model for an ADN with the consideration of the ZIP model of the loads and PV nodes. The proposed method is not limited to radial topology and can handle high R/X ratio branches. Case studies on the IEEE 37-node distribution network show a high accuracy and the proposed method is applicable to practical uses such as linear or convex optimal power flow of the ADN.