Real-time wave excitation force estimation for an experimental multi-DOF WEC

Hillis, Andrew; Brask, Annette; Whitlam, Craig

doi:10.1016/j.oceaneng.2020.107788

Cited by 13 publications

(5 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, this approach requires wave measurement, which may be not applicable for some offshore applications. In this case, one promising approach is to estimate the excitation force by designing unknown input observers [6,315,618,352].…”

Section: Discussionmentioning

confidence: 99%

“…Research work on control systems [352,835] for WEC devices is also ongoing, with specific emphasis on passive control [814,673,271], reactive control [354,241,733,7], phase control [96,688], and latching control [762,847,770,452]. Sandia National Laboratory in the US, Wave Energy Scotland, and the Centre of Ocean Research (COER) at the National University of Ireland, Maynooth, are all involved in augmenting WEC control systems in particular.…”

Section: Efficiency Augmentationmentioning

confidence: 99%

See 1 more Smart Citation

Modelling and Optimisation of Wave Energy Converters

Ning¹,

Ding²

2022

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 99%

Section: Efficiency Augmentationmentioning

confidence: 99%

Modelling and Optimisation of Wave Energy Converters

Ning¹,

Ding²

2022

View full text Add to dashboard Cite

“…Herein, WES can be dependably achieved via the in situ wave-measuring buoy. Additionally, WEC motion can be utilized to identify wave excitation force/moment [14,34,35]. Thereby, WES could be theoretically estimated via the identified wave excitation force/moment and the corresponding transfer function.…”

Section: Ltb Internal-mass Position Adjustmentmentioning

confidence: 99%

Multi-Timescale Lookup Table Based Maximum Power Point Tracking of an Inverse-Pendulum Wave Energy Converter: Power Assessments and Sensitivity Study

Yue,

Zhang,

Meng

et al. 2023

Energies

View full text Add to dashboard Cite

A novel, inverse-pendulum wave energy converter (NIPWEC) is a device that can achieve natural period control via a mass-position-adjusting mechanism and a moveable internal mass. Although the energy capture capacity of a NIPWEC has already been proven, it is still meaningful to research how to effectively control the NIPWEC in real time for maximum wave energy absorption in irregular waves. This paper proposes a multi-timescale lookup table based maximum power point tracking (MLTB MPPT) strategy for the NIPWEC. The MLTB MPPT strategy was implemented to achieve a theoretical “optimal phase” and “optimal amplitude” by adjusting both the position of the internal mass and linear power take-off (PTO) damping. It consists of two core parts, i.e., internal mass position adjustment based on a 1D resonance position table and PTO damping tuning based on a 2D optimal PTO damping table. Furthermore, power assessments and sensitivity study were conducted for eight irregular-wave sea states with diverse wave spectra. The results show that energy period resonance and the lookup table based PTO damping tuning have the highest possibility of obtaining the maximum mean time-averaged absorbed power. Additionally, both of them are robust to parameter variations. In the next step, the tracking performance of the MLTB MPPT strategy in terms of changing sea states will be studied in-depth.

show abstract

“…The system input is a vector comprising the 4‐DOF PTO control force u and

{{boldf}_{eR}, {boldf}_{eF}}

, which are the 6‐DOF wave excitation force vectors acting on the reactor and float calculated using BEM‐derived frequency‐dependent excitation coefficients as shown in Equation () [16]. The system output is

{false[x_{R} {\dot{boldx}}_{F} false]}^{T}

.…”

Section: The Wavesub Wecmentioning

confidence: 99%

Wave energy converter platform stabilisation and mooring load reduction through power take‐off control

Hillis

Courtney

Brask

2021

IET Renewable Power Gen

Self Cite

View full text Add to dashboard Cite

Mooring systems are a significant capital cost of a floating wave energy converter and their premature failure negatively impacts operational costs. Excessive peak loads and accumulated fatigue damage can lead to failure, so these factors are cost drivers in wave energy converter design. Here, the potential to reduce platform motion and mooring loads through modification of the power take-off (PTO) control are investigated. An approximate velocity tracking control strategy is implemented with a linear quadratic regulator design method using differential weighting of system states. It is demonstrated that the controller can be tuned to capture similar mean power to an optimally tuned, passively damped system while significantly reducing mooring line cyclic loading. The relative accumulated fatigue damage in the mooring lines in a high energy sea-state is found to be reduced by between 43% and 92% as a result of using the approximate velocity tracking control strategy.

show abstract

Real-time wave excitation force estimation for an experimental multi-DOF WEC

Cited by 13 publications

References 15 publications

Modelling and Optimisation of Wave Energy Converters

Modelling and Optimisation of Wave Energy Converters

Multi-Timescale Lookup Table Based Maximum Power Point Tracking of an Inverse-Pendulum Wave Energy Converter: Power Assessments and Sensitivity Study

Wave energy converter platform stabilisation and mooring load reduction through power take‐off control

Contact Info

Product

Resources

About