An Iterative Refining Approach to Design the Control of Wave Energy Converters with Numerical Modeling and Scaled HIL Testing

Abstract

The aim of this work is to show that a significant increase of the efficiency of a Wave Energy Converter (WEC) can be achieved already at an early design stage, through the choice of a turbine and control regulation, by means of an accurate Wave-to-Wire (W2W) modeling that couples the hydrodynamic response calibrated in a wave flume to a Hardware-In-the-Loop (HIL) test bench with sizes and rates not matching those of the system under development. Information on this procedure is relevant to save time, because the acquisition, the installation, and the setup of a test rig are not quick and easy. Moreover, power electronics and electric machines to emulate turbines and electric generators matching the real systems are not low-cost equipment. The use of HIL is important in the development of WECs also because it allows the carrying out of tests in a controlled environment, and this is again time- and money-saving if compared to tests done on a real system installed at the sea. Furthermore, W2W modeling can be applied to several Power Take-Off (PTO) configurations to experiment different control strategies. The method here proposed, concerning a specific HIL for testing power electronics and control laws for a specific WECs, may have a more general validity.

Performance Comparison of Offline and Real-Time Models of a Power Take-Off for Qualification Activities of Wave Energy Converters

“…Moreover, the hardware-in-the-loop (HIL) testing scheme is considered as a state-of-the-art tool to bridge the gap between the laboratory and the real operational environment in several industries, such as automotive, aerospace and power systems. In the wave energy sector, HIL testing has already been used for different PTO concepts [12], [13], [14], [15], [16], [17].…”

Multi-Objective Shape Optimization of Multi-Axis Wave Energy Converter

“…The hydrodynamic model is a critical part of any WEC design optimization process since it is one of the most important elements influencing the best WEC configuration. However, the hydrodynamic model used for WEC optimization forces is an uneasy trade-off between computing practicability and modeling accuracy [15]. The dynamics associated with point absorber WEC are presented as follows.…”