Design, Modelling, and Optimization of Grid-Connected Solar Photovoltaic and Wind Hybrid System: A Case Study of Dire Dawa City

Abstract

Ethiopia predominantly generates its electricity via hydropower, a resource that is dependent on fluctuations in water levels. To address this issue, this thesis investigates the design, modeling, and optimization of a grid-connected solar photovoltaic (PV) and wind hybrid system for Dire Dawa City, Ethiopia. The Felema district was selected for this research due to its potential for solar and wind resources, proximity to the existing grid, and availability of suitable land. The optimal configuration of 20 MW of solar PV, 22.5 MW of wind power, and 10 MW from the grid was determined using the HOMER Pro software. This hybrid system has a net present cost of $42.3 million and a levelized cost of energy of $0.037/kWh. To model and simulate the performance of this hybrid system, MATLAB/Simulink was utilized. For the solar PV system, a fuzzy logic control-based maximum power point tracking (MPPT) algorithm was implemented and shown to have superior tracking efficiency compared to other MPPT methods. The wind energy conversion system employed a doubly-fed induction generator (DFIG) with an indirect optimal torque control (OTC) strategy. The complete PV-wind hybrid system was then connected to the utility grid according to IEEE standards. The results of this study demonstrate the technical and economic viability of a grid-connected solar-wind hybrid system to supplement Ethiopia's hydropower-dominated electricity generation, improving the country's energy security and resilience.