For wave energy to become a major future contributor of renewable energy it is a requirement that the efficiency and reliability of the Power Take-Off (PTO) systems is significantly improved. However, the cost of installing and testing PTO-systems at sea is very high. The focus of the current paper is therefore on the design and commissioning of a full scale wave simulator for testing PTO-systems for point absorbers. The challenge is to be able to design a system, which mimics the behavior of a wave when interacting with a given PTO-system – especially when considering discrete type PTO-systems. The paper presents the designed system, including the major design considerations. A model of the complete system is presented and controllers for the system are developed. These enable the system to emulate the wave behavior and the wave–float interaction. Finally both simulation and experimental results are presented, showing that the system is able to emulate real waves up to three meters in height and with a resulting force of more than 800 kN.
International Journal of Marine Energy, 2016, Vol 13
Control; Mechatronic design; Power Take-Off; Testing facility; Wave power