Reliability analysis of distribution systems considering sub-unavailabilities

Abstract

This paper presents a mathematical model that allows a comprehensive description of the restoration process by means of sub-repair times when an element of an electric distribution system fails. The model allows to simulate the effects of devices such as remote controlled breakers, sectionalizers, isolators and fault indicators, on the continuity of supply of distribution systems. This methodology makes use of the classical reliability formulation for series systems but modifying it, taking into account the distinct functions of each type of device, and analyzing their specific effects on the different stages of detection of fault, isolation, repair actions, etc. These stages are modeled using sub-unavailabilities, which correspond to different steps of the restoration process. The main contributions of this paper are the explicit formulation of different repair times and the associated sub-unavailabilities, its use for device modeling and the application to perform systematic reliability analysis of the investments on continuity of supply.