ESR 1: Trinity College Dublin

Secondments: SWIRL GENERATORS LTD

Amongst the more widely researched solutions on WECs, oscillating water column (OWC) has attracted considerable attention as these make one of the most effective means of absorbing wave energy. Recently, a new model of a wave energy device has been proposed that is a single body, consisting of a surface float rigidly linked to a substantial mass of trapped sea water. This is an arrangement that looks similar to an OWC, but in operation is quite different, - here the heaving buoy responds to the wave excitation, not the water column.

To maximise the power captured by the PTO, innovative control algorithms  are to be formulated and investigated in this project. Two different types of control algorithms are proposed to be formulated. A semi-active (dependent on time-scale) will be developed for a week-by-week or day-by-day changing of reference mass to re-set for significant change in weather conditions. This will lead to a re-tuning of the device and can be used e.g. for a storm situation control. In addition, a new multi-objective H∞ robust control with a pneumatic air pressure controller will be formulated to optimise the power production from PTO.

 

ESR 2: Aalborg University

Secondments: SWIRL GENERATORS LTD

The aim of the research is to develop new control algorithms for the operation of wave energy devices to optimize the produced electrical power in a stochastic environment. In practical applications, there are several constraints on the motions of the absorber and the actuator force. These have a significant influence on maximization of absorbed power. To this end, the research focuses on stochastic constrained optimal control problems. A large part of the work will be in cooperation with a wave energy company (SWIRL GENERATORS LTD), in Trinity College, Dublin. The controller will generally be useful for hydraulic PTO control and optimization for other wave energy converters. For the published papers refer to the "Outreach" page.

 

ESR 3: Floating Power Plant

Secondments: Aalborg University

Floating Power Plant (FPP) consists of a floating platform supporting a wind turbine and four wave energy absorbing bodies. The device has several advantages when compared with competitors, for instance: safer access, better power quality (less energy production intermittence), higher uptime, broader range of deployment depths, etc.

The wave absorbers of the FPP plant moves inside a chamber with little clearance, resulting in large fluid velocities, large pressure gradients and corresponding numerical complications. There are no off-the-shelf numerical codes available for handling this problem. Since the hydrodynamic forces on the wave absorbers are essential for the global dynamics of the plant, a proper solution to this problem is essential for handling the vibration control problem of the plant.  The research in this workpackage will be dedicated to addressing this problem by modification of available Computational Fluid Dynamics or Smoothed Particle Hydrodynamics numerical codes. Following the development of a new numerical algorithm, an innovative control algorithm for the FPP will be designed for operational and storm conditions.