Publica
Hier finden Sie wissenschaftliche Publikationen aus den FraunhoferInstituten. Balancing power output and structural fatigue of wave energy converters by means of control strategies
 Energies 7 (2014), Nr.4, S.22462273 ISSN: 19961073 

 Englisch 
 Zeitschriftenaufsatz, Elektronische Publikation 
 Fraunhofer IWES () 
Abstract
In order to reduce the cost of electricity produced by wave energy converters (WECs), the benefit of selling electricity as well as the investment costs of the structure has to be considered. This paper presents a methodology for assessing the control strategy for a WEC with respect to both energy output and structural fatigue loads. Different active and passive control strategies are implemented (proportional (P) controller, proportionalintegral (PI) controller, proportionalintegralderivative with memory compensation (PID) controller, model predictive control (MPC) and maximum energy controller (MEC)), and load timeseries resulting from numerical simulations are used to design structural parts based on fatigue analysis using rainflow counting, StressNumber (SN) curves and Miner's rule. The objective of the methodology is to obtain a costeffective WEC with a more comprehensive analysis of a WEC based on a combination of well known control strategies and standardised fatigue methods. The presented method is then applied to a particular case study, the Wavestar WEC, for a specific location in the North Sea. Results, which are based on numerical simulations, show the importance of balancing the gained power against structural fatigue. Based on a simple cost model, the PI controller is shown as a viable solution.