Optimal Power Flow of a Battery/Wind/PV/Grid Hybrid System: Case of South Africa

Abstract

Photovoltaic and wind systems have been demonstrated to be sustainable alternatives of producing electricity in rural electrification, particularly in islanded applications. Currently, the advancement of research in the area of power electronics has allowed the connection of these renewable resources to the grid with bidirectional power flow. In this work, the optimal power scheduling for a grid-connected photovoltaic–wind–battery hybrid system is proposed to maximize the use of solar and wind resources to assist customers at demand side. The developed model for the hybrid system’s optimal power flow management aims to minimize electricity purchased from the grid while maximizing the energy sold to the grid as well as the production of the renewable sources subject to the power balance, photovoltaic, wind, and battery storage outputs as well as other operational constraints. Relating to demand-side management, a control technique is developed to optimally schedule the power flow from the different components of the hybrid system over 24-h horizon. Simulations are performed using MATLAB, and the results demonstrate that operating the proposed hybrid system under the developed optimal energy management model can reduce the operation cost and allow consumers to generate substantial income by selling power to the grid.