Stability limit and uniqueness of voltage solutions for radial power networks

The planning and operation of a distribution system depend heavily on the load flow solutions obtained In this paper, the uniqueness of feasible voltage solution and its stability limit of radial distribution networks is analyzed. The DistFlow method is employed to find the load flow solutions for radial power networks. By using this method, an equivalent 2-bus network can be obtained during the solving process. It is proposed that only one feasible voltage solution exists for a radial power network. Moreover, the feasibility can be judged directly from the sign of the Jacobian determinant of the equivalent 2-bus network obtained. A 22-bus practical system was tested to justify the approach.