Optimal Economic Operation Strategy of Wind Turbine-Diesel Unit with Pumped Hydro Energy Storage

This paper presents an optimal power sharing for a hybrid energy system (HES), which is composed of a wind turbine (WT), a pump-hydro turbine, and a diesel unit (DU). The water storage reservoir is indispensable to ensure the reliability and to improve the system's overall efficiency. The aim of this study is to find the lowest operating cost of generation sources by taking into account the startup/shutdown cost, the maintenance cost, and the fuel cost. As wind and water are the sources of free energy, the maximum use of available energy from WT and hydro turbine (HT) is necessary. The DU is decided to be ON/OFF based on binary particle swarm optimization (BPSO) to minimize the fuel consumption and to improve the energy reliability. In order to compare the cost-effectiveness, the simulation stage has been conducted for three scenarios of DU operation during 24h. In the first scenario, the DU is continuously operated at its maximum efficiency point, without using an optimization technique, if the power produced by a WT and HT is unmet the load demand. The second scenario deals with employing the DU with its optimal power determined by particle swarm optimization (PSO). The third scenario demonstrates how the DU is controlled to be ON/OFF using BPSO, by considering technical and economic constraints. The simulation results clearly indicate the appropriateness of the proposed method for achieving the best operation of the DU.