A New Method for the Construction of Maximal Steady-State Security Regions of Power Systems

This paper presents a method to compute maximal steady-state security regions based on the DC load flow model. The proposed method consists of three steps. First, an initial region (hyperbox) is obtained explicitly using an analytic method. A developed algorithem is then utilized to expand the upper and lower bounds of the initial region in as many dimensions as possible. The algorithm is based on a necessary and sufficient condition for a region to be secure. Due to the proposed condition, the algorithm is computationally very efficient. Finally, the expanded security region is used to initiate a set of optimization problems, which can be solved to yield maximal regions. Applications of security regions to power system planning and operation are discussed. Numerical testing indicates that the algorithms proposed to expand the initial region produces nearly maximal security regions. The results of the paper provide a systematic way to deal with practical issues such as the size of security regions and computational efficiency.