Three-phase power flow based on four-conductor current injection method for unbalanced distribution networks

This work presents a new formulation for the power flow problem, with explicit representation of the neutral conductor and grounding. This methodology has been named the four-conductor current injection method (FCIM). The Newton-Raphson method is applied to solve the set of nonlinear current injection equations that are derived using phase coordinates, and the complex variables are written in rectangular form. The proposed algorithm can be used to analyze both balanced and unbalanced systems, meshed or radial, with controls and distributed generation, and is shown to be very efficient and robust for large scale systems. Index Terms--Current injection method, distributed generation, distribution systems, four-wire systems, induction machine modeling, three-phase power flow, unbalanced operation.