Design and control of a stand-alone hybrid power system

• A new stand-alone hybrid power system design and control are carried out.
• The system includes the combination of solar, wind, fuel cell, storage systems and a dump load.
• A grid interaction unit has also been added to the hybrid system.
• A good total harmonic distortion (THD) value has been observed although a nonlinear load is attached.

This work presents a control of stand-alone hybrid system including photovoltaic (PV), wind turbine, fuel cell (PEMFC), storage systems and a dump load (in our case, an electrolyzer). All these sources are connected by a continuous bus to three phase load through a DC–AC converter. A strategy for the power management is designed for the proposed hybrid system to supervise power amount among various energy resources, the storage system and the dump load. In the design, the PV and wind systems are considered as main power resources, whereas PEMFC is used as an additional support, and the dump load is used for the effect of consumption of the surplus power available from sources (i.e. PV and wind), when the battery has been charged completely. The hybrid system includes a modified control algorithm, which has been developed to maintain the DC bus voltage at its reference through the regulation of the DC–DC bidirectional converter between the battery and DC bus. A dynamic model of various components of stand-alone hybrid system is presented along with a maximum power point tracking (MPPT) algorithms of the PV and wind system. The effectiveness of this modified control algorithm method has been verified using the Matlab/Simulink software.