A comparison of approaches integrating power take-off systems into wave energy converters simulations

Paper in proceeding, 2025

In the design of a wave energy converter (WEC) in general, one critical aspect is to develop the power take-off (PTO) system since it has a significant impact on the overall energy harnessing efficiency. Therefore, the modelling of a PTO system should be considered in the simulation of a WEC and carefully tuned with its parameters to guarantee prediction accuracy. However, it is a challenge to model a WEC system with the hydrodynamic system, mooring system and PTO system in a fast and robust way due to various limitations of commercial software and in-house codes. This paper compares four WEC system models, which include either a simplified or a full PTO system model. They also integrate simplified, modified or full hydrodynamic system models. The most complex model considers a complete WEC system with a full hydrodynamic system, full PTO system and mooring system. The study object is the point-absorber WEC WaveEL 3.0 designed by Waves4Power AB. The power performance of the WEC is calculated for six sea states using the four models with different fidelities. The results of the four models are analyzed, and their pros and cons are discussed. Modelling strategies to fulfil different simulation goals are suggested.