A predictive power control of Doubly fed induction generator for wave energy converter in irregular waves

Abstract

In last decades, renewable energy resources are considered as an alternative energy resource to the World's excessive energy demand. An extremely abundant and promising source of energy exists in oceans. Currently, there are several wave energy converters to harness this energy. Some of them, as in tidal applications, use the Doubly-fed induction generator. This paper deals then with a predictive power control of this generator based Wave Energy Converter under irregular wave climate which is modeled as time series elevation from using Bretschneider spectra. In the proposed control approach, the predicted output power was calculated using a linearized statespace model. The DFIG-based WEC power tracking performances further illustrates the dynamic features of the proposed predictive power control approach.

Review of Marine Hydrokinetic Power Generation and Power Plant

“…This method of generation was analyzed, implemented, and tested in [27,28] using the linear version intended for wave generator applications, and an application for the OWC was given in [29].…”

A Study about Performance and Robustness of Model Predictive Controllers in a WEC System

“…Although, since the last decade, more complex controllers like MPC (model predictive control) are being employed. The interest in implementing MPCs in WEC systems is motivated by the need to increase the productive/economic viability of these systems; due to the fact that these controllers allow them to minimize mechanical fatigue in their structures (limiting the operating ranges) and to focus the control strategy on the maximization of the extracted power directly.Actually, several authors have developed predictive controllers for WECs [7][8][9][10][11][12][13][14][15][16][17]. These MPCs can be grouped according to the characteristics of the cost function optimized.…”

“…On the one hand, the authors in [8,10-16] used a cost function in which the extraction of mechanical power was directly maximized. Whereas, on the other hand, in [9,17], the authors proposed a cost function to maximize power extraction by minimizing the error between the speed of oscillation of the system and a setpoint for it. In addition to the above classification, MPCs can be distinguished according to the mathematical model used for their design.…”

“…On one side, in [9][10][11]13,14], a reduced model was used for the design, which did not consider the dynamics of the radiation force. Meanwhile,in [7,8,12,13,[15][16][17], such dynamics were considered in the design model. Moreover, the previous works did not consider the dynamics of the power take-off system (PTO), neither in the evaluation, nor in the design of the MPCs.…”

“…Finally, the treatment carried out in the case of non-feasibility when solving the cost functions with restrictions should be highlighted. In this aspect, the works in [9,10,13] considered a more complete approach by adding soft constrains in the case of non-feasibility.This paper analyses the main approaches of MPCs applied to PAW systems [8][9][10][11][12][13][14][15][16][17]. In addition, a new design is proposed: MPC based on a model with an embedded integrator for controllers that follow a setpoint for the speed of oscillation of the PAW.…”