A New Efficient Nonlinear Programming-Based Method for Branch Overload Elimination

Abstract

A simple and efficient method for eliminating branch overloads in power systems is presented in this paper. The overloads are eliminated by corrective control actions, which are computed by an efficient and accurate nonlinear programming method. Generation rescheduling and load shedding are the main controls used. The idea of adaptative local optimization is introduced, making the computation of appropriate generation rescheduling a very efficient process. Load shedding is used as a last resort, when further generation rescheduling is no longer possible. Heuristics are added in order to speed up the computation process and to take into account some practical aspects of power systems operation. A special procedure is carried out in case of critical situations, where emergency control actions are defined. The method's general idea is to keep the new secure operating point as close as possible to the original one while minimizing the amount of load shedding. The method can be a helpful tool for operation planning studies, security analysis, and reliability evaluation of power systems. Simulations have been carried out for small test to large real life systems in order to show the effectiveness of the proposed method.