OPTIMAL EXPANSION PLANNING OF DISTRIBUTION NETWORK WITH DISTRIBUTED GENERATION BY UTILIZING GRID-BASED MULTI-OBJECTIVE HARMONY SEARCH ALGORITHM (CASE STUDY: DEBREMARKOS DISTRIBUTION NETWORK)

Abstract

Electrical energy plays a vital role in the socio-economic development. To combat for the power system profile problems, distribution substation needs to be established considering future expansion due to urbanization. Debre Markos (D/M) distribution network needs expansion planning to meet the growing load demand. To evaluate the capability of the existing distribution network and to supply reliable power for future expansion, demand forecast for the years 2017/18-2022/23-2027/28 has been performed by using trend forcasting technigue withl east sequre approximation and evaluating the load flow by using backward-forward sweep load flow. According to the results, the existingnetwork cannot meet the existing load demand and it has major problems of increased voltage deviation and power loss. In this thesis, D/M distribution network expansion planning considering future demand growth and distributed generation placement and sizing is carried out using Grid based Multi-Objective Harmony Search Algorithm (GrMHSA). The total real power loss (Pl), total reactive power loss (Ql) and total voltage deviation (VD) at the target year for the base case by taking the existing line and the projected bus data are 7434.9kw, 7391.8kvar and 58.6952p.u for D/M Feeder 3 and 470.7058kw, 404.5524kvar and 6.4412p.u for D/M Feeder 4 respectively. After applying GrMHSA optimization technique for DG sizing and placement, the total Pl, total Ql and VD at the target year are 95.398kw,124.979kvar and 0.479p.u for D/M Feeder 3 (F3A and F3B) and 30.811kw, 37.727kvar and 0.533p.u for D/M Feeder 4 respectively