Real-Time Optimization Control of a Floating Type Wave Energy Converter

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K15223
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 24020:Marine engineering-related
• Research Institution: National Institute of Maritime, Port and Aviation Technology
• Principal Investigator: Taniguchi Tomoki 国立研究開発法人海上・港湾・航空技術研究所, その他部局等, 研究員 (80586678)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 波力発電装置 / 非線形モデル予測制御 / 実時間制御

Outline of Final Research Achievements

We applied a nonlinear model predictive control (NMPC) which incorporates the continuous GMRES method to a floating-point-absorber type wave energy converter (FPAWEC), and evaluated motions and power production performance by model tests. The sampling time of the tests was 50 milliseconds. We investigated fundamental characteristics of the NMPC by an onshore test bench, which was constructed by a power take-off module of the FPAWEC model. The performance of the NMPC was also assessed by 1-Dof PAWEC model test. Since the FPAWEC has a prismatic joint to connect a float and a spar; the FPAWEC has motion constrains, equations of motion of the FPAWEC were derived by the Kane’s equation, which uses the principle of virtual power. The NMPC was implemented on the FPAWEC model, and motions and power production performance were compared with other control strategy, the resistive load control, and the approximate complex-conjugate control with considering the copper loss.

Free Research Field

船舶海洋工学

Academic Significance and Societal Importance of the Research Achievements

日本近海は欧米に比べて波パワーが小さい．また，遠浅の海域も少なく，海洋再生エネルギーを効率よく取得するには，沖合に展開可能な浮体式施設の活用が望ましい．
本研究では，先行研究では1自由度系PAWECへの適用に留まっていたNMPCをFPAWECに適用し，水槽試験にて制御周期50 msでの実時間制御を確認すると伴に，他の制御法を実装した場合と運動性能及び発電性能を比較した．2浮体系となるFPAWECにもNMPCの様な制約条件付最適化手法が適用可能であることを実験的に示した点は学術的意義がある．また，本研究成果は，沖合利用可能で高効率な浮体式波力発電施設の開発に資するため，社会的意義もあると思われる．