DECOMPOSITION METHODS FOR SOLVING POWER NETWORK PROBLEMS

Abstract

Due to fast growing developments, the demand for electrical energy is increasing rapidly. Therefore the size and complexity of power network is also growing up tremendously. As the size of network increases it becomes difficult and time consuming to analyze the complete network . This study is directed towards the development of efficient decomposition method which can be used for load flow solution, contingency analysis and optimal load flow solutions. A very efficient and robust method method has been introduced for the solution of the load flow problems and for the power system optimization problem. The decomposition method presented in this study, decomposes the large size networks into number of blocks from the weak coupling point such that the effect on the boundary nodes is minimum. In the presented technique, each block contains total number of its existing buses plus the external boundary buses. The buses connecting the boundary lines and present buses in the remaining network termed as external boundary buses, are modeled as swing buses. The load flow solution of each block is carried out by Gauss-Seidel method. The boundary bus voltages are updated after solving each block After solving each block, the coordination of blocks is carried out for getting the solution of complete network.The practical .networks are solved as a whole and with the proposed decomposition technique, and results are compared . The proposed decomposition technique for load flow problem is successfully applied to a number of test systems including 26-bus model of SPC transmission system, test system, 64-bus and 103-bus model.