Phase-decoupled method for three-phase power-flow analysis of unbalanced distribution systems

This paper presents a three-phase power-flow solution method for unbalanced distribution networks, in which each phase is modelled in a decoupled way and therefore can be solved independently. All component models are described using only individual phase voltages, admittances and independent current sources. The component models are decoupled into each phase through compensation current injections whenever necessary. The solution method is based on the Z_bus Gauss approach, with implicit factorisation of the Y_bus matrix for each phase. The approach significantly reduces the overall amount of computation needed to solve sequential three-phase power-flows, becoming itself eligible for use on the real-time operation of modern distribution systems. Test results, showing both the accuracy and speed-up performances of the decoupled approach when applied to several networks, are presented.