Energy dispatch strategy for a photovoltaic–wind–diesel–battery hybrid power system

• An energy dispatch model of a PV–wind–diesel–battery hybrid system is proposed.
• Model predictive control is applied to the hybrid system.
• Model maximizes use of renewable energy and minimizes of diesel generator usage.
• Effect of seasonal variations in demand, wind and solar resources on fuel cost is shown.
• Diesel consumption is higher in winter than in summer.

In this paper, an energy dispatch model that satisfies the load demand, taking into account the intermittent nature of the solar and wind energy sources and variations in demand, is presented for a solar photovoltaic–wind–diesel–battery hybrid power supply system. Model predictive control techniques are applied in the management and control of such a power supply system. The emphasis in this work is on the co-ordinated management of energy flow from the battery, wind, photovoltaic and diesel generators when the system is subject to disturbances. The results show that the advantages of the approach become apparent in its capability to attenuate and its robustness against uncertainties and external disturbances. When compared with the open loop model, the closed-loop model is shown to be more superior owing to its ability to predict future system behavior and compute appropriate corrective control actions required to meet variations in demand and radiation. Diesel consumption is generally shown to be more in winter than in summer. This work thus presents a more practical solution to the energy dispatch problem.