A Framework Using Uncertainties in the Composite Power System Reliability Evaluation

In Bulk Power System Reliability Evaluation (BPSRE), realistic operating condition constraints are important issues. The limits based on stability and voltage considerations should be adhered to at all times to prevent blackouts, as voltage collapse problems account for uncertainties in power system operation, which is due to uncontrollable progressive decline in voltage. The aspects of uncertainties about future load growth, fuel cost, environmental regulations, etc., are difficult to specify properly within a long-term forecasting probabilistic model. On the other hand, the simple LP models are inadequate in satisfying realistic system objectives and constraints. Dynamical feature of load modeling may be critical in the computation of voltage collapse-related bulk power system reliability indices. Also, the control problem has attracted greater interest as the desire to transport power over longer distances has increased. In this work, while formulating mathematical formulation by considering the voltage collapse phenomena in the existing framework of BPSRE, the reactive power control variables are optimized by using Fuzzy linear programming. The uncertainties in system probabilistic parameters, like Forced Outage Rates, which affects largely the final indices, are also defined using the concept of Fuzzy Number and Linguistic variables. The new indices are found to reflect the integration of probabilistic models and fuzzy concepts. The proposed method has been tested on AEP-14 bus test system, and the results are compared with conventional ones and presented to demonstrate the effect of uncertainties in the system probabilistic parameters.