Power system reliability evaluation and quality assessment by fuzzy logic technique

The basic function of a power system is to supply electrical energy to both large and small customers as economically as possible, and with an acceptable degree of reliability and quality. Reliability and quality are two essential measures and important components of all power system planning and operation procedures. Reliability is one of the key design factors when designing complex, critical and expensive systems. This paper presents a fuzzy logic technique for evaluating the reliability of complex and large power systems to deal with their imprecise variables. In the proposed technique, fuzzy set theory was used to evaluate the coefficients of different terms in reliability expression. Systems with hundreds of buses and tens of complex stations can be analyzed using advanced and numerically effective large-scale algorithms for reliability and quality assessment. An advanced computer program for large-scale reliability and quality assessment is studied and applied to a full-scale model of the Saudi Arabia electricity system. The proposed algorithm is very useful to the on-line security assessment of large and complex power systems. The results obtained are claimed to have far-reaching implications on various planning and operation aspects of the Saudi power system.