Abstract
This work builds a numerical electro-mechanical coupled model of a laboratory-scale horizontal-axis tidal turbine and analyses the turbulent flow impact in the mechanical and electrical variables of the coupled system. Computational Fluid Dynamics/Large Eddy Simulation simulates turbulent flow, and the Actuator Line Method models the rotor blade dynamics. An electrical generator, controllers, power electronics, transformer, transmission lines and electrical grid compose the electrical system. Balances of hydrodynamic-body forces and rotor-electromagnetic torques manage the hydro-mechanical and electro-mechanical interactions, respectively.
Time series of the tidal turbine mechanical and electrical characteristics, hydrodynamic forces distribution over rotor blades, and flow development over the computational domain are analysed. Results show that turbulence influences the tidal turbine’s mechanical and electrical components, thereby compromising the quality of the power supplied to the grid.
The coupled system response undergoing turbulent flow is compared by filtering the control signals for maximum power generation. The simulated mechanical variables are compared with laboratory measurements, and a good agreement is found. The control signal filtering allows the mitigation of the turbulent flow impact in the coupled system model. This mitigation is considerable for electromagnetic torque, generator and grid powers at around 70 %.