Optimal Integration of Renewable Energy–Based Distributed Generation Units in Radial Distribution System

Abstract

Determining the optimal integration of renewable energy–based distributed generation units (DGUs) in electric distribution systems brings many positive technical and economic impacts and contributes significantly for improving the performance of the distribution system. The suitable installation of DGUs is always a challenging problem because the output behaviors of DGUs, specifically photovoltaic units (PVUs) and wind turbine units (WTUs) are strongly affected by stochastic natural conditions. In this study, the main purpose is to address optimal nonlinear constrained problems with three targets in the multiobjective function (MOF) for minimizing (1) total power loss, (2) voltage deviation, and (3) the cost of purchasing energy from the main grid considering the uncertainties of solar irradiance and wind speed in the actual region in Binh Thuan Province, Vietnam. This paper solves three problems related to optimal connection of DGUs in the distribution system considering constant power generation and consumption with unity power factor (PF) (Problem 1), constant power generation and consumption with optimal PF (Problem 2), and time-varying power generation and consumption with optimal PF (Problem 3). Besides, this research also proposes a novel meta-heuristic optimization algorithm called revised coyote optimization algorithm (RCOA) for addressing the optimization problems of the simultaneous integration of DGUs in IEEE 69-bus radial distribution system. The obtained results in above three problems are compared with the original and published methods to demonstrate the superior economic and technical benefits of the proposed method.