A method for planning phase-shifting transformers using linearized networks sensitivities

The authors examine an alternative method for alleviating electric power transmission line overloads that occur during the loss of one or more transmission lines of a large-scale interconnected power system. The proposed method is based on optimizing power-flow paths through the various remaining system transmission lines. The control of power flow paths is achieved using phase-shifting transformers. An algorithm is presented which searches for a nearly optimum location of several phase-shifting transformers so that most overloads can be prevented. This algorithm is intended as a tool for power-system planning studies. The performance of the method was demonstrated on a nine-bus test system