Open AccessMaximising power conversion for heaving point absorbers using a reference‐based control technique
Author(s) -
Wahyudie Addy,
Saeed Omsalama,
Jama Mohammed,
Noura Hassan,
Harib Khalifa
Publication year - 2017
Publication title -
iet renewable power generation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.005
H-Index - 76
eISSN - 1752-1424
pISSN - 1752-1416
DOI - 10.1049/iet-rpg.2016.0255
Subject(s) - control theory (sociology) , pid controller , weighting , servo , controller (irrigation) , servomechanism , computer science , control engineering , engineering , control (management) , temperature control , physics , mechanical engineering , biology , artificial intelligence , agronomy , acoustics
This study considers maximising conversion between the mechanical and electrical powers for heaving point absorbers (HPAs). The objective is implemented by generating the buoy's velocity reference by designing the intrinsic resistance. The authors designed the intrinsic resistance using a rapid procedure involving the mechanical and electrical models of HPAs. The electrical power conversion can be improved by tuning a weighting constant with the constraints on the maximum value of the control force and the power take‐off utilisation index. The value of the intrinsic resistance is varied based on irregular sea states, which are characterised by their significant heights and peak angular frequencies. A simple robust proportional‐integral‐derivative (PID) controller is utilised in the servo feedback control system to follow the velocity reference. The PID controller is designed using the complex polynomial stabilisation to convert the robust performance into a set of linear programming problems. A set of admissible PID controller is obtained to satisfy the robust performance specifications. The authors tested the proposed method in various nominal and perturbation scenarios, and its performance was compared with existing reference and non‐reference based HPA control strategies.