Improving the Energy Conversion Efficiency for Hydrokinetic Turbines Using MPPT Controller

The research presented in this paper involves the design of a power control system for a hydrokinetic turbine previously tested in real operating conditions. A maximum power point tracking (MPPT) algorithm was designed and simulated using the required parameters for a specific electric generator. The proposed system consists of a generator connected to the hydrokinetic turbine, a three-phase uncontrolled rectifier, a direct current (DC) boost converter with MPPT control to extract maximum available power, and a buck converter to control the amount of power delivered to the load. In order to test the MPPT algorithm, we built the individual blocks on the basis of the corresponding equations of each component. The algorithm considered the specific parameters of the previously tested turbine as input data and simulated the same water velocities for which the turbine had been tested. Thus, the simulation predicted a power output of 105 W for a water velocity of 1.33 m/s, 60 W for 1 m/s, and 30 W for 0.83 m/s. The efficiency of the control system was demonstrated when the instantaneous power value was maintained at a maximum point, regardless of the rotational speed according to the experimental power curves of the driving rotor obtained for certain water velocities.