The wave energy converter control competition (WECCCOMP): Wave energy control algorithms compared in both simulation and tank testing

The wave energy control competition established a benchmark problem which was offered as an open challenge to the wave energy system control community. The competition had two stages: In the first stage, competitors used a standard wave energy simulation platform (WEC-Sim) to evaluate their controllers while, in the second stage, competitors were invited to test their controllers in a real-time implementation on a prototype system in a wave tank. The performance function used was based on converted energy across a range of standard sea states, but also included aspects related to economic performance, such as peak/average power, peak force, etc. This paper compares simulated and experimental results and, in particular, examines if the results obtained in a linear system simulation are borne out in reality. Overall, within the scope of the device tested, the range of sea states employed, and the performance metric used, the conclusion is that high-performance WEC controllers work well in practice, with good carry-over from simulation to experimentation. However, the availability of a good WEC mathematical model is deemed to be crucial

CONCEPTION DE SYSTEMES DE COMMANDE AVANCEE PAR CALCULATEUR (METHODOLOGIE ET APPLICATIONS)

GRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF

Spectral Control of Wave Energy Converters with Non-Ideal Power Take-off Systems

Spectral control is an accurate and computationally efficient approach to power-maximising control of wave energy converters (WECs). This work investigates spectral control calculations with explicit derivative computation, applied to WECs with non-ideal power take-off (PTO) systems characterised by an efficiency factor smaller than unity. To ensure the computational efficiency of the spectral control approach, it is proposed in this work to approximate the discontinuous efficiency function by means of a smooth function. A non-ideal efficiency function implies that the cost function is non-quadratic, which requires a slight generalisation of the derivative-based spectral control approach, initially introduced for quadratic cost functions. This generalisation is derived here in some detail given its practical interest. Two application case studies are considered: the Wavestar scale model, employed for the WEC control competition (WECCCOMP), and the 3rd reference model (RM3) two-body heaving point absorber. In both cases, with the approximate efficiency function, the spectral approach calculates WEC trajectory and control force solutions, for which the mean electrical power is shown to lie within a few percent of the true optimal electrical power. Regarding the effect of a non-ideal PTO efficiency upon achievable power production, and concerning heaving point-absorbers, the results obtained are significantly less pessimistic than those of previous studies: the power achieved lies within 80–95% of that obtained by simply applying the efficiency factor to the optimal power with ideal PTO

Éditorial

SCOPUS: ed.jinfo:eu-repo/semantics/publishe

Experimental evaluation of a hybrid MPC strategy for vehicle start-up with an Automated Manual Transmission

International audienc

Unified MPC strategy for idle-speed control, vehicle start-up and gearing applied to an Automated Manual Transmission

International audienc

A phenomenological model for torque transmissibility during dry clutch engagement

International audienc

An efficiency-aware continuous adaptive proportional-integral velocity-feedback control for wave energy converters

International audienceThe main objective in hydrodynamic control of wave energy converters (WECs) is the maximization of the energy captured from the waves. Latching control, model predictive control and "PI" control are examples of implementable strategies surveyed in the literature. "PI" control is the common name of a form of hydrodynamic control where the control force applied to the captor is a proportional-integral feedback of captor velocity. While suboptimal, it has the merit of being simple, requiring only straightforward computations and can be considered a standard solution for WECs with a four-quadrant power takeoff (PTO) system. Adaptive "PI" control has been already discussed in the literature, usually using a gain-scheduling approach, with optimal gains precomputed off-line for a representative set of sea states and applied as a function of estimated sea state conditions. In most literature, only average on-line estimations of sea states have been proposed, with time windows of several minutes. Such intermittent adaptive control laws are clearly suboptimal in terms of energy recovery, since the control gains are not continuously updated whereas the sea state is continuously time-varying. In this paper we present a continuously adaptive "PI" control strategy, whose gains are adapted on-line on a wave-to-wave basis, based on a real-time estimate of the dominant wave frequency of the wave force. The PTO efficiency is taken into account. The proposed control method is validated and compared through experiment for irregular sea states