Dynamic Model of the Seawater Low-Head Turbine for Wave Energy Conversion

In this paper, a dynamic model of a seawater low-head turbine for an Overtopping BReakwater Energy Conversion (OBREC) system is presented. The model is not based on the physical similarity of hydraulic machines, as classical models are, and is easy to tune and lightweight to execute. These characteristics make the model ideal for preliminary control simulations or hardware-in-the-loop tests because it removes the necessity of depicting a particular turbine before starting the control design. This study provides the static characteristics of the developed models in terms of torque and power as a function of speed and water height. These diagrams agree with the experimental studies conducted on physical turbines of similar characteristics as reported in other studies. In addition, the models were dynamically tested for energy conversion and power exchange with a power grid. The perturb and observe method was adopted for the test, and it was observed that its tuning depended on the water wavelength.