Decomposition of Real and Reactive Power Flows: A Method Suited for On-Line Applications

Guided by the experience that real power is most sensitive to nodal phase angles and reactive power to voltage magnitudes, a new method of power flow optimization is developed which exploits this decoupling and consequently reduces problem size. This decomposition of the real and reactive equations results in the formation of two subproblems-one corresponding to the real power equations and the other to the reactive power equations. In practice, the two subproblems are alternatively solved until the desired accuracy is attained. The method has considerable potential for real time applications such as voltage control, economic dispatch, security analysis, etc., where in many situations the solution of only one subproblem will be required. The algorithm was originally developed for applications related to system security and for this purpose linear programming is used for optimizing each of the subproblems. A test case study of a 38-node network demonstrates the convergence properties of the algorithm.