A loop-analysis theory based linear power flow method for three-phase distribution power system

The linear power flow (LPF) models are particularly important in the context of optimization algorithms for three-phase distribution systems with the high penetration of distributed renewable generations. With several approximations on network modelling, voltage drop calculation, link power calculation, voltage controlled bus and ZIP loads, this paper proposed a three-phase LPF model for three-phase unbalanced distribution networks based on loop-analysis theory. The method can deal with voltage-controlled (PV) & Load (PQ) buses and ZIP loads. The approximations of the star and delta connections ZIP loads are also analyzed. Test results based on several standard IEEE test feeders and an improved 615bus test system proved the effectiveness and accuracy of the proposed algorithm. The proposed LPF solution gives a simple, more robust, and potentially faster solution for modern distribution power system.