Uncertainty Analysis in Power Systems

This chapter comprehensively deals with various uncertain problems in power system operation such as uncertainty load analysis, probabilistic power flow, fuzzy power flow, economic dispatch with uncertainties, fuzzy economic dispatch, hydrothermal system operation with uncertainty, unit commitment (UC) with uncertainties, VAR optimization with uncertain reactive load, and probabilistic optimal power flow (P-OPF). Probabilistic analysis and fuzzy theory can be used to analyze the uncertainty load. A method of obtaining a stochastic model is to take a deterministic model and transform it into a stochastic model by (1) introducing random variables as inputs or as coefficients or as both; and (2) introducing equation errors as disturbances. The economy of UC of power systems is influenced by approximations in the operation planning methods and by the inaccuracies and uncertainties of input data.