scholarly journals Robust Adaptive PI Control of Wave Energy Converters with Uncertain and Nonlinear Dynamics

2022 ◽  
Author(s):  
Nguyen Hoai Nam
Keyword(s):  
Optimal Control ◽  
Wave Energy ◽  
Control Strategy ◽  
Pi Control ◽  
Optimal Control Strategy ◽  
Robust Optimal Control ◽  
Point Absorber ◽  
Wave Energy Converters ◽  
Robust Adaptive ◽  
Control Implementation

There exist several approaches to design the optimal control strategy to harvest wave energy with a point absorber. However they are generally based on the assumption that the WEC and the PTO dynamics are well-known. In the practical WEC control implementation, this is generally not the case. The objective of this paper is to design a robust optimal control strategy that can take into account the uncertain WEC and PTO dynamics. Our choice is a robust adaptive PI control law. The proposed controller is validated and compared through simulation for irregular sea states.

scholarly journals Robust Adaptive PI Control of Wave Energy Converters with Uncertain and Nonlinear Dynamics

2022 ◽  
Author(s):  
Nguyen Hoai Nam
Keyword(s):  
Optimal Control ◽  
Wave Energy ◽  
Control Strategy ◽  
Pi Control ◽  
Optimal Control Strategy ◽  
Robust Optimal Control ◽  
Point Absorber ◽  
Wave Energy Converters ◽  
Robust Adaptive ◽  
Control Implementation

There exist several approaches to design the optimal control strategy to harvest wave energy with a point absorber. However they are generally based on the assumption that the WEC and the PTO dynamics are well-known. In the practical WEC control implementation, this is generally not the case. The objective of this paper is to design a robust optimal control strategy that can take into account the uncertain WEC and PTO dynamics. Our choice is a robust adaptive PI control law. The proposed controller is validated and compared through simulation for irregular sea states.

Optimising Reactive Control in Non-Ideal Efficiency Wave Energy Converters

2014 ◽  
Author(s):  
T. Strager ◽  
A. Martin dit Neuville ◽  
P. Fernández López ◽  
G. Giorgio ◽  
T. Mureşan ◽  
...  
Keyword(s):  
Optimal Control ◽  
Wave Energy ◽  
Electrical Power ◽  
Control Parameters ◽  
Reactive Control ◽  
Simple Method ◽  
Point Absorber ◽  
Wave Energy Converters ◽  
The Mean ◽  
Energy Converters

When analytically optimising the control strategy in wave energy converters which use a point absorber, the efficiency aspect is generally neglected. The results presented in this paper provide an analytical expression for the mean harvested electrical power in non-ideal efficiency situations. These have been derived under the assumptions of monochromatic incoming waves and linear system behaviour. This allows to establish the power factor of a system with non-ideal efficiency. The locus of the optimal reactive control parameters is then studied and an alternative method of representation is developed to model the optimal control parameters. Ultimately we present a simple method of choosing optimal control parameters for any combination of efficiency and wave frequency.

Wave Energy Extraction Maximization Using Direct Transcription

2012 ◽  
Author(s):  
James T. Allison ◽  
Allen Kaitharath ◽  
Daniel R. Herber
Keyword(s):  
Optimal Control ◽  
Wave Energy ◽  
Nonlinear Models ◽  
Cost Effective ◽  
Ocean Waves ◽  
Open Loop ◽  
Energy Extraction ◽  
Optimal Control Strategy ◽  
Direct Transcription ◽  
Wave Energy Converters

Wave energy converters (WECs) extract energy from the motion of ocean waves. A variety of different WEC devices have been studied over the past several decades, with emphasis on cost-effective energy extraction. Active control has been shown to improve energy production significantly. Here we investigate energy extraction potential of a tethered heaving cylinder WEC using direct transcription (DT), an open-loop optimal control strategy. This enables direct inclusion of asymmetric constraints on power and tether force, practical considerations not considered in previous studies, and opens the door to WEC optimal control problems with more realistic nonlinear models and integration of control design with physical system design.

Empirical Demonstration of Acausal Control Strategies for Wave Energy Converters

2013 ◽  
Author(s):  
James Eder ◽  
James Bretl ◽  
Kathleen Edwards
Keyword(s):  
Real Time ◽  
Wave Energy ◽  
Control Strategy ◽  
Control Strategies ◽  
Complex Conjugate ◽  
Optimal Control Strategy ◽  
Wave Energy Converters ◽  
Wave Elevation ◽  
Linear Damping ◽  
Empirical Demonstration

The benefit of acausal control strategies for Wave Energy Convertors (WECs) is empirically demonstrated in a wave tank. An upstream wave gage is used to provide real time predictions of the wave elevation at the WEC’s location. Using a sub-optimal control strategy based upon complex conjugate control, these predictions are used to generate real time force commands for the Power Take Off (PTO) system. Empirical comparisons are made between the acausal control strategy and a simple linear damping approach.

Application of Optimal Control Strategy to Converter Gas Recovery System

2012 ◽  
Vol 38 (6) ◽  
pp. 1017 ◽  
Author(s):  
Jia-Yan ZHANG ◽  
Zhong-Hai MA ◽  
Xiao-Bin QIAN ◽  
Shao-Ming LI ◽  
Jia-Hong LANG
Keyword(s):  
Optimal Control ◽  
Control Strategy ◽  
Optimal Control Strategy ◽  
Gas Recovery ◽  
Recovery System ◽  
Converter Gas
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