Title :
Tunable Control Strategy for Wave Energy Converters With Limited Power Takeoff Rating
Author :
Tedeschi, Elisabetta ; Molinas, Marta
Author_Institution :
Norwegian Univ. of Sci. & Technol., Trondheim, Norway
Abstract :
In wave energy converters (WECs), the maximum power extraction would be achievable at the expense of a very high rating of the electric and power electronics equipment. The goal of this paper is to show how a convenient tradeoff between high-power extraction and viable electrical device rating can be achieved by a proper choice of the WEC control strategy. Referring to a direct coupled point absorber in heave operating in regular waves, it will be analytically shown how most common control techniques impact on both the power performance and the power takeoff (PTO) rating. Thus, a tool that can assist in the preliminary PTO sizing by taking into account the main constraints imposed by the application is obtained. Following, an adaptive control strategy including a reactive component is proposed, whose goal is to improve the overall system performance when the WEC is already operative in the sea. Its effectiveness in increasing the average power extraction while respecting the PTO peak power constraint is proved by computer simulations in both regular and irregular waves, and specific analyses also including the PTO force/torque limitation are finally developed.
Keywords :
adaptive control; power convertors; power generation control; wave power plants; PTO force-torque limitation; PTO peak power constraint; PTO rating; WEC control strategy; adaptive control strategy; computer simulations; direct coupled point absorber; high-power extraction; irregular waves; limited power takeoff rating; maximum power extraction; power electronic equipment; power takeoff rating; reactive component; tunable control strategy; viable electrical device rating; wave energy converters; Damping; Force; Loading; Peak to average power ratio; Power electronics; Reactive power; Resistance; Control strategies; irregular waves; point absorber; power takeoff (PTO); wave energy;
Journal_Title :
Industrial Electronics, IEEE Transactions on
DOI :
10.1109/TIE.2011.2181131