Detection of power system operation violations via fuzzy set theory

The purpose of this paper is to apply fuzzy set theory to one of the basic dimensions of power system reliability, the magnitude of a failure. The fuzzy set theory technique introduces an index which is developed from a membership function describing the power system behavior. The membership function developed for specific problems solved by fuzzy set theory is the measure of system behavior and its degree of compatibility. The proposed fuzzy set will include all buses violating their operating constraints and the membership function will rank the magnitudes of failures and identify the weak areas that are subject to violation in the normal operating state. A relationship between the membership function versus p.u./kV identifying the behavior of the operating states for the operator is also identified. The fuzzy set concept in this paper is implemented on the IEEE 25-bus Reliability Test System. Single-level contingencies evaluating the system voltage violations are analyzed and documented.