Combined active and reactive dispatch with multiple objectives using an analytic hierarchical process

A fully coupled active and reactive dispatch using linear programming and an analytic hierarchical process is developed. The purpose of combined active and reactive dispatch (CARD) is to achieve the overall objective of minimum generation cost and to improve the distribution of reactive power and voltage, subject to constraints which ensure system security. Security is defined as the maintenance of individual circuit flows, generator reactive power output and system voltages within limits under normal system conditions and contingency cases. The weighting factors of different kinds of objective functions are determined by an analytic hierarchical process (AHP), considering the relative importance of these objective functions. The developed method is demonstrated through its application to determine the combined active and reactive dispatch of a 713-node network representing a practical power system, provided by the National Grid Company plc (NGC). The calculation results show that a good balance can be achieved among the various objectives and a satisfactory generation pattern is obtained from the enhanced CARD program