Toward a CPFLOW-based algorithm to compute all the type-1 load-flow solutions in electric power systems

This paper presents a potential algorithm based on continuation power flow (CPFLOW) to compute all the Type-1 load-flow solutions. Type-1 solutions are of a single positive real-part eigenvalue associated with Jacobian of load-flow equations and are used in conjunction with techniques such as energy methods and the voltage instability proximity index (VIPI) for assessing system voltage stability. The benefits of the proposed algorithm are the following. The algorithm has the potential to find all the Type-1 load-flow solutions by tracing a small number of homotopy curves. Traditional methods, which can locate some of the Type-1 solutions, suffer from the uncertainty that there might be another Type-1 solution that might be more suitable for voltage stability assessment. This uncertainty is eliminated if all the Type-1 solutions are located. The proposed algorithm has been tested for two example systems, and encouraging results have been obtained. © 2005 IEEE.