Three-phase power-flow methods using sequence components

Abstract

Power flow is an important tool in power system planning and operational studies. The single-phase power-flow algorithms assume a balanced power system operation and a balanced power system model. There are many cases where the system unbalance cannot be ignored due to unbalanced loads, untransposed transmission lines and a combination of balanced with unbalanced networks in distribution systems. Therefore a three-phase powerflow program that deals with unbalanced power system will be a useful analytical tool. A variety of three-phase power-flow algorithms have been studied for solving unbalanced power systems. These algorithms can be categorized into two groups. The first group solves a general network structure such as Newton Raphson method [1]-[5], Fast Decoupled method [3], [6], the hybrid method [7], and the bus admittance method [8]. The second group considers primarily the radial structure of distribution networks such as the compensation based method.