This paper summarises the key outcomes of WP2 of the IMAGINE project, which aimed to provide technical specifications that can assist in the definition of the load environment for a novel 250kW Electro-Mechanical Generator (EMG) Power Take-Off (PTO). A series of complex, yet realistic, design situations were considered, namely those involving operational and parked scenarios, framed in a shortlist of design load cases (DLCs). A range of wave energy converter (WEC) types and target sites were covered, aiming to maximise the range of applicability of the PTO.
Fully coupled WEC-Sim models were created to obtain estimates of key metrics that allow the definition of the loading environment affecting the PTO. The coupling of the environmental conditions with the type of WEC (and its operational state) strongly conditions the WEC loading, and thus EMG PTO loading. ULS and FLS metrics were derived, to characterise extreme and fatigue loads affecting the PTO.
The analysis allows a range of key findings to be derived. These include generic findings with implications to WEC and / or WEC subsystem design, and that are applicable in a wider context to the wave energy field. In particular, the methodology followed to quantify e.g. ULS loads provides insight into the applicability and robustness of different numerical approaches. In future work, it is also foreseeable that the developed WEC models will be integrated in a hardware-in-the-loop (HWIL) environment to allow representative load inputs to be recreated in controlled, onshore based, real-time tests involving a physical EMG PTO.