Evaluation of the losses in unbalanced three-phase power systems

The problem of evaluating the losses in unbalanced three-phase power systems is considered. To take into account the uncertainties which can affect the losses, the evaluation is effected by applying probabilistic techniques of analysis; both closed form solutions and Monte Carlo procedures including correlation among the loads are presented. The proposed approaches, in order to reduce the computational efforts, employ a simplified losses modeling. Numerical applications to a test system are also discussed, showing that the results are not much different from those obtainable by the Monte Carlo simulation of the exact nonlinear model based on the three-phase load-flow