Numerical Modeling of a Direct-Drive Tidal Turbine System for Laboratory Testing

This work presents a numerical modeling framework for a laboratory-scale tidal turbine equipped with a directdrive Permanent Magnet Synchronous Generator (PMSG) and a power conversion system. The proposed framework extends conventional modeling approaches by integrating a computational hydrodynamics model within a MATLAB/Simulink environment to simulate the complete Power Take-Off (PTO) system. A fast Boundary Integral Equation Method (BIEM) solver, developed at CNR-INM, is used to estimate the hydrodynamic loads on the turbine rotor blades under varying flow velocities and rotational speeds. The BIEM solver, written in Fortran, is valid for horizontal-axis turbines operating in arbitrary inviscid flow and is coupled with a detailed electromechanical model of the generator and converter through a custom co-simulation interface. The integrated hydrodynamic/electromechanical model provides a support tool for the preliminary design of the turbine PTO system and allows investigation of the performance of alternative control strategies under highly variable onset flow conditions. Simulation results demonstrate the capability of platform to reproduce key system dynamics, offering a valuable tool for control development, system optimization, and future Hardware-in-the-Loop (HIL) applications.