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A model predictive control-based power converter system for oscillating water column wave energy converters

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journal contribution
posted on 2023-05-19, 12:49 authored by Rajapakse, G, Shantha Jayasinghe Arachchillage, Alan FlemingAlan Fleming, Michael NegnevitskyMichael Negnevitsky
Despite the predictability and availability at large scale, wave energy conversion (WEC) has still not become a mainstream renewable energy technology. One of the main reasons is the large variations in the extracted power which could lead to instabilities in the power grid. In addition, maintaining the speed of the turbine within optimal range under changing wave conditions is another control challenge, especially in oscillating water column (OWC) type WEC systems. As a solution to the first issue, this paper proposes the direct connection of a battery bank into the dc-link of the back-to-back power converter system, thereby smoothening the power delivered to the grid. For the second issue, model predictive controllers (MPCs) are developed for the rectifier and the inverter of the back-to-back converter system aiming to maintain the turbine speed within its optimum range. In addition, MPC controllers are designed to control the battery current as well, in both charging and discharging conditions. Operations of the proposed battery direct integration scheme and control solutions are verified through computer simulations. Simulation results show that the proposed integrated energy storage and control solutions are capable of delivering smooth power to the grid while maintaining the turbine speed within its optimum range under varying wave conditions.

History

Publication title

Energies

Volume

10

Issue

10

Article number

1631

Number

1631

Pagination

1-17

ISSN

1996-1073

Department/School

Australian Maritime College

Publisher

MDPI AG

Place of publication

Switzerland

Rights statement

© 2017 by the authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) http://creativecommons.org/licenses/by/4.0/

Repository Status

  • Open

Socio-economic Objectives

Wave energy