A5039393057- Wave and Wind Energy Systems
- HVDC Systems and Fault Protection
- Wind Energy Research and Development
- Fluid Dynamics and Vibration Analysis
- Frequency Control in Power Systems
- Coastal and Marine Management
- Microgrid Control and Optimization
- Oceanographic and Atmospheric Processes
- Offshore Engineering and Technologies
- Ocean Waves and Remote Sensing
- Mechanical stress and fatigue analysis
- Advanced Numerical Methods in Computational Mathematics
- Tropical and Extratropical Cyclones Research
- Perovskite Materials and Applications
National University of Ireland, Maynooth
2013
A model-free algorithm is developed for the reactive control of a wave energy converter. Artificial neural networks are used to map significant height, period, and power take-off damping stiffness coefficients mean absorbed maximum displacement. These values computed during time horizon spanning multiple cycles, with data being collected throughout lifetime device so as train off-line every 20 horizons. Initially, random selected controller achieve sufficient exploration. Afterwards,...
In this article, reinforcement learning is used to obtain optimal reactive control of a two-body point absorber. particular, the Q-learning algorithm adopted for maximization energy extraction in each sea state. The controller damping and stiffness coefficients are varied steps, observing associated reward, which corresponds an increase absorbed power, or penalty, owing large displacements. generated power averaged over time horizon spanning several wave cycles due periodicity ocean waves,...
An algorithm has been developed for the resistive control of a nonlinear model wave energy converter using least-squares policy iteration, which incorporates function approximation, with tabular and radial basis functions being used as features. With this method, controller learns optimal power take-off damping coefficient in each sea state maximization mean generated power. The performance is assessed against two online reinforcement learning schemes: Q-learning SARSA. In both regular...
For wave energy converters, the input resource has a typical period of 5–20 s depending on site location and dominant seastates. Wave converters generally produce mechanical power twice per cycle therefore storage available, electrical output half resource. These regular changes induce voltage change at point connection (POC) which is proportional to amplitude same frequency. Therefore coupling converter will cause flicker POC, may exceed permitted limits under specific conditions. This...
Wave Energy Converters (WECs) have been in development for several decades with some devices now coming close to commercial realities. As such, pilot projects are being developed, particularly the UK and Ireland, deploy WECs on a pre-commercial array scale. The ultimate ambition is multiple installed ‘wave farm’ similar fashion offshore wind farms. For large scale farms inter-array export electrical systems can represent more than 20% of project’s capital expenditure. Submarine power cables...
Here, least-squares policy iteration, a reinforcement learning algorithm, is applied to the reactive control of wave energy converter for first time. Simulations linear point absorber are used this analysis. The focus study on implementation displacement constraints. use penalty term effective in teaching controller avoid selection combinations damping and stiffness coefficients that would result excessive displacements particular sea states. However, can learn actions bad only after trying...
Voltage flicker is a power quality problem caused by regularly oscillating active and reactive either from load or generator. The regular oscillations induce voltage change at the grid connection which proportional to amplitude of oscillation same frequency. impedance (grid strength) point factor in oscillation. frequency band interest for evaluation 0.01-20Hz, most severe 8.8Hz. primary resource wave energy converters lies within this range. Therefore coupling input output converter will...
Many wave energy converter developers opt to carry out scaled prototype open water testing of their device as part technology development. Developers who have done this recently include Sea Power (1/5 scale, Galway Bay, 2017), CorPower (1/4 EMEC, 2018) and Marine Systems FaBTest, ongoing). Scaled offers several benefits, including more representative realisations sub-systems, identification resolution technological issues associated with scaling-up, de-risking the manufacturing marine...
The subject of this paper is the development physical and numerical models a tank test programme to investigate performance multi wave energy absorber platform (MWAP). inspired by proposed designs for large scale platforms be used floating offshore wind (FOW). modular design model enables variable number absorbers mounted platform, with up 9 tested simultaneously. are simplified version submerged pressure differential device, each incorporating set mechanical springs approximate response...