Development of an efficient utility interactive combined wind/photovoltaic/fuel cell power system with MPPT and DC bus voltage regulation

In this paper, development and simulation of an efficient small-scale centralized dc-bus grid connected hybrid wind/photovoltaic/fuel cell for supplying power to a low voltage distribution system are presented. The hybrid system consists of wind and photovoltaic as a primary power system. A fuel cell is added as a secondary system to ensure continuous power supply and to take care of the intermittent nature of wind and photovoltaic. The objective of this study is to design and control a hybrid system that guarantees the energy continuity. A simple control method is applied to the proposed configuration to simultaneously achieve three desired goals: to extract maximum power from each hybrid power system component; to guarantee dc bus voltage regulation at the input of the inverter; and to transfer the total produced power to the grid at unity power factor, while fulfilling all necessary interconnection requirements. The power fluctuation of the proposed hybrid system has been reduced as compared to that of each individual system and it has been completely suppressed using the FC system. The simulation results indicate that the dc-dc converters are very effective in tracking the maximum power of the wind and photovoltaic sources, the fuel cell controller responds efficiently to the deficit power demands. With both wind and photovoltaic systems operating at their rated capacity, the system can generate power as high as 2 kW and the fuel cell does not need to be utilized in such cases. (C) 2010 Elsevier B.V. All rights reserved.