Novel prediction methods applied to voltage controls

Two methods which assist voltage control decisions by predicting the impact of voltage controllers on power system voltages are discussed. Both methods offer possibilities for voltage control studies and are particularly adapted to expert system implementations. First, control regions are readily determined using rule-based searches among the electric system topology and based on initial reactive power flows. Second, sensitivities of voltages with respect to controls are computed using adjoint-network-based voltage predictions which do not require Jacobian computations and which are well adapted to admittance switching actions. These methods are used in the framework of an expert system currently being developed by the authors. The theories and implementations of both methods are discussed, and results using the IEEE-118 power system are presented