Hardware-In-the-Loop test rig for the ISWEC wave energy system

The Hardware-In-the-Loop (HIL) simulation is a powerful mean to reduce costs in the design and manufacturing process of an engineering system. HIL techniques allow to use real components inside a simulation of a mathematical model. In this work such techniques are used on the ISWEC wave energy system. ISWEC (Inertial Sea Wave Energy Converter) converts sea waves energy to electric energy by means of the gyroscopic effects produced by a spinning flywheel. The peculiarity of the system lays in the fact that all the moving parts needed to produce energy are sealed inside a hull and therefore protected from the aggressive ocean climate. During the research process on the ISWEC, the gyroscope and the electric generator have been manufactured and mounted on a test rig able to simulate the wave actions on the hull of ISWEC. Those real parts of the system have been replaced inside the full mathematical model of ISWEC. Such HIL system is validated against real wave tank tests carried out at the INSEAN in Rome. The HIL simulations proved to reproduce the real behavior in water waves of ISWEC with errors as small as the 10%.