Reliability Assessment of Distribution System with Distribution Generation Dangila, Ethiopia

Abstract

The reliability assessment provides to determine existing power system reliability. Equipment
failure decrease reliability and major contributory factor for power system unreliability.
Therefore, the objective of this study was reliability assessment for distribution with DG units
and without DG units, Dangila/Ethiopia substation from 2015 to 2016. SAIFI =774.93,
SAIDI =1231.48, CAIDI = 1.589, ASAI =85.96% and ASUI =14.04 were base case of
indexes. Therefore, the system needs improvement since the standard of country/Ethiopian
Electric Agency (EEA) was (SAIFI =20 and SAIDI= 25). Distribution generation was used to
improve the system. DG was placed at feeder D-07, with five suggested locations (0km, 66km,
80km, 100km, 113.3km, and 146km from substation). And when DG was placed further from
Supply point or the reliability of the power system will be improved more. The size of a single
DG was found to be 3.13 MW. The assessment shown feeder seven (D-07) had more outage
with base case of SAIFI =636, SAIDI=833, CAIDI =1.311. After DG added at D-07 the
indexes were SAIFI =20.0868, SAIDI =25.109, CAIDI =1.25 and ASAI =99.71 % which
were improved and in the standards of country.