Reliability assessment of distribution network for medium voltage system. Case study: Kigoma substation

Abstract

The Electrical Power System (EPS) with its generation, as well as its transmission and distribution networks are subjected to many events such as accidents, random component failures, increasing power outage due to adverse weather and increased network risk due to aging assets. These kinds of events are unpredictable, but they can be taken into account when deciding the level of distribution at which the system should survive, on other hand EPS is a complicated system from the operation and infrastructure points of view. Despite this; it has to provide the end customers with continuous and reliable power supply. In this study, the reliability assessment of Medium-Voltage (MV) distribution network is investigated. The study examines one practical part of the MV network in KIGOMA substation of south Province with three feeders: Butare, Ntongwe and Gatumba. The network used in this study is the radial distribution system, which represents typical urban distribution systems consisting of residential and industrial customers. The degree of reliability of supply is measured by the frequency, duration and magnitude of disturbances to the electricity supply. Both system indices and system worth indices are calculated and evaluated. In addition, the degree of reliability of five case studies is conducted, which can investigate the effects of automation, ageing and load growth.