Fuzzy logic based evaluation of optimal reliability of bulk power system : a multiobjective approach

Security considerations are important issues in Bulk Power System Reliability Evaluation [BPSRE], as the existing models are based on adequacy analysis and in many cases do not consider the realistic operating conditions. The limits based on stability and voltage considerations have to be observed at all time to prevent blackouts. Due to the complexity of the problem, the existing probabilistic methods encounter objectives and constraints which are not known preciously, specifically when the planning is to be carried out for future. Also some aspects of uncertainty which always exist in practical system do not lend themselves to the analysis by probability based methods. We focuses on 1) Modeling of Voltage Stability and Reactive Power control problem in BPSRE 2) Modeling of uncertainty by Fuzzy Logic method. The reactive power control variables are optimized by using Fuzzy LP which will effectively model the uncertainties present in the power system.. 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 found will reflect the integration of probabilistic models and Fuzzy concepts. The proposed method can be tested on weak power system to demonstrate the effect of voltage stability and uncertainties on Bulk Power System Reliability Indices