An Evaluation of the Effect of Weakly Formalized Factors on the Reliability Index of Power Facilities

Abstract

Effective operation of intelligent electronic devices and fiber optic cables, which are used in the formation of modern power facilities, as well as their reliability indices depend on changing external operating conditions. In this respect, it is important to evaluate the effect of weakly formalized factors, which are not taken into account in the traditional reliability calculation methods, on the reliability indices of the elements of power facilities. A digital substation (DSS) was adopted as the object of study. A method for evaluating DSS reliability has been developed taking into account the effect of weakly formalized factors in the form of temperature and humidity of the environment. The findings concerning the extent of the effect of weakly formalized factors on the reliability indices of DSS elements using the fuzzy-logic membership function based on a quantitative description of qualitative (verbal) concepts, such as temperature and humidity, are obtained. These concepts describe the conditions of changing environment. The facility availability factor that shows the DSS ability to withstand different external effects while maintaining power supply to consumers is considered as a parameter characterizing the DSS reliability. It is also recommended to use the developed method when evaluating the reliability of Smart Grid elements of different power systems taking into account the effect of weakly formalized environmental factors on them.