Sliding mode control for heaving wave energy converter

The most accurate wave energy converter models for heaving point absorbers include nonlinearities, which increase as resonance is achieved to maximize the energy capture. Over the power production spectrum and within the physical limits of the devices, the efficiency of wave energy converters can be enhanced by employing a control scheme that accounts for these nonlinearities. This paper proposes a sliding mode control for a heaving point absorber that includes the nonlinear effects of the dynamic and static Froude-Krylov forces. The sliding mode controller tracks a reference velocity that matches the phase of the excitation force to ensure higher energy absorption. This control algorithm is tested in regular linear waves and is compared to a complex-conjugate control and a nonlinear variation of the complex-conjugate control. The results show that the sliding mode control successfully tracks the reference and keeps the device displacement bounded while absorbing more energy than the other control strategies. Furthermore, due to the robustness of the control law, it can also accommodate disturbances and uncertainties in the dynamic model of the wave energy converter.

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Second Order Sliding Mode Control of Oscillating Water Column Wave Energy Converters for Power Improvement

IEEE Transactions on Sustainable Energy ◽

10.1109/tste.2020.3035501 ◽

2020 ◽

pp. 1-1

Author(s):

Daniel Tim Gaebele ◽

Mario Edgardo Magana ◽

Ted Brekken ◽

Joao C. C. Henriques ◽

Ana Alexandra de Freitas Dias Ipolliti Carrelhas ◽

...

Keyword(s):

Sliding Mode Control ◽

Water Column ◽

Wave Energy ◽

Sliding Mode ◽

Second Order ◽

Oscillating Water Column ◽

Mode Control ◽

Wave Energy Converters ◽

Second Order Sliding Mode ◽

Energy Converters

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Sliding mode and fuzzy logic control for heaving wave energy converter

52nd IEEE Conference on Decision and Control ◽

10.1109/cdc.2013.6760122 ◽

2013 ◽

Cited By ~ 1

Author(s):

Addy Wahyudie ◽

Muhammad Abdi Jama ◽

Ali Assi ◽

Hassan Noura

Keyword(s):

Fuzzy Logic ◽

Wave Energy ◽

Fuzzy Logic Control ◽

Sliding Mode ◽

Wave Energy Converter ◽

Energy Converter ◽

Logic Control

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Sliding Mode Control for Power Output Maximization in a Wave Energy Systems

Energy Procedia ◽

10.1016/j.egypro.2015.07.332 ◽

2015 ◽

Vol 75 ◽

pp. 265-270 ◽

Cited By ~ 4

Author(s):

Oscar Barambones ◽

J.M. Gonzalez de Durana

Keyword(s):

Sliding Mode Control ◽

Wave Energy ◽

Power Output ◽

Sliding Mode ◽

Energy Systems ◽

Mode Control ◽

Output Maximization

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Spring-resonance-assisted maximal power tracking control of a direct-drive wave energy converter

Transactions of the Institute of Measurement and Control ◽

10.1177/01423312211013212 ◽

2021 ◽

pp. 014233122110132

Author(s):

Ning Wang ◽

Yusen Jia ◽

Shui Fu

Keyword(s):

Wave Energy ◽

Tracking Control ◽

Sliding Mode ◽

Wave Energy Converter ◽

Direct Drive ◽

Maximal Power ◽

Energy Converter ◽

System A ◽

Control Framework ◽

Fast Adaptation

In this paper, to finely accommodate large-range wave frequencies on same sea areas, a spring resonance mechanism is created to facilitate maximal power tracking control of a direct-drive wave energy converter (DWEC) that is expected to be equipped on same sea areas, whereby the spring-resonance-assisted module is devised by mover-coaxial springs and reshapes the resonant-frequency pertaining to a specific spectrum. By virtue of modeling the spring-resonance-assisted DWEC system, a finite-time disturbance observer (FDO) is deployed to rapidly compensate environmental disturbances. Accordingly, the FDO-based integral sliding-mode (ISM) control framework is proposed, to accurately achieve the resonance between the DWEC buoy and wave, thereby contributing to spring-resonance-assisted maximal power tracking control (SR-MPTC) of the DWEC. Simulation studies and comprehensive comparisons demonstrate that the proposed SR-MPTC scheme performs remarkably fast adaptation and accurately maximal power tracking in the presence of disturbances and spring resonance assistance.

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