RT Journal Article T1 Speed control of oil-hydraulic power take-off system for oscillating body type wave energy converters A1 Gaspar, José F. A1 Kamarlouei, Mojtaba A1 Sinha, Ashank A1 Xu, Haitong A1 Calvário, Miguel A1 Faÿ, François Xavier A1 Robles, Eider A1 Soares, C. Guedes AB The variable displacement oil-hydraulic pumps for the Power Take-Off (PTO) of wave energy converters must work above 80% of maximum displacement in order to have an overall efficiency of approximately 94.5%. This is achieved by controlling their rotational speed when the oil-hydraulic power fluctuates in time. Three speed control strategies have been presented, the first fixing the maximum possible speed in each sea state, the second by slowly varying the pump speed between speed peak values and average ones, and the third by working with highly variable speed reference values. The worst pump efficiency is achieved with the first strategy while the best one with the third strategy. However, the first has less impact than the third one in the pump lifecycle. On the other hand, the second strategy is used to make a trade-off between pump efficiency and lifecycle. However, this paper presents a fourth speed control strategy, which is a hybrid of the second and third strategies. So, the objectives of this paper were to know if these strategies are implementable in a test rig and also on a new PTO concept and determining what modifications should be introduced in these PTO strategies and hardware. This paper also contributes with the application of new methodologies in this field of research for the modelling of pump efficiency and pressure control, such as Neuro-Fuzzy modelling and Fuzzy Logic control systems. SN 0960-1481 YR 2016 FD 2016-11-01 LA eng NO Gaspar , J F , Kamarlouei , M , Sinha , A , Xu , H , Calvário , M , Faÿ , F X , Robles , E & Soares , C G 2016 , ' Speed control of oil-hydraulic power take-off system for oscillating body type wave energy converters ' , Renewable Energy , vol. 97 , pp. 769-783 . https://doi.org/10.1016/j.renene.2016.06.015 NO Publisher Copyright: © 2016 Elsevier Ltd. NO This work was performed within the Strategic Research Plan of the Center for Marine Technology and Ocean Engineering, which is financed by Portuguese Foundation for Science and Technology (Fundação para a Ciência e Tecnologia-FCT) and the project “Generic hydraulic power take-off system for wave energy converters” funded by the Portuguese Foundation for Science and Technology (FCT) under contract PTDC/EMS-SIS-1145/2014 . The testing has received support from MARINET, a European Community – Research Infrastructure Action under the FP7 “Capacities” Specific Programme, grant agreement nr. 262552 . The research leading to these results is also part of the OceaNET project, which has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement nr. 607656 . DS TECNALIA Publications RD 28 sept 2024