SOLVING FOR 3-PHASE CONDUCTIVELY ISOLATED BUSBAR VOLTAGES USING PHASECOMPONENT

Three phase busbar voltage solutions, derived from the Y-bus network m odel and unbalanced current injections, are used in a variety of three phase power system network analysis applications, such as Z-bus power flow and short circuit studies. When phase coordinate analysis is use d to solve these problems, existing techniques can result in divide-by -zero errors. These errors occur when the network contains one or more islands conductively isolated from the ground. This paper combines th e limit processes of calculus and linear circuit analysis to derive an algorithm which can perform a LDL(T) factorization of the phase coord inate Y-bus model of such networks. This factorization can then be use d to solve for voltages in islands conductively isolated from ground, yet energized through magnetic coupling to one or more islands with a ground reference.