Development of a smart wave energy converter with tuned variable inertial mass

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K18908
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 24:Aerospace engineering, marine and maritime engineering, and related fields
• Research Institution: University of Tsukuba
• Principal Investigator: Asai Takehiko 筑波大学, システム情報系, 准教授 (90775793)
• Project Period (FY): 2018-06-29 – 2023-03-31
• Keywords: 波力発電 / 同調回転慣性質量機構 / イナーター / 再生可能エネルギー

Outline of Final Research Achievements

This research introduces a point absorber wave energy converter (WEC) with tuned variable inertial mass. The tuned inertial mass (TIM) was introduced in the field of civil engineering as a control device for structures subjected to seismic loadings. Moreover, a point absorber WEC equipped with TIM, in which a motor is used, has been proposed and its effectiveness has been shown. However, since the TI mechanism takes advantage of the resonance of the inertial mass to absorb energy from vibrating buoys, it has been pointed out that the TI could not respond well to the dominant period changes of ocean waves.
Thus, a system to control the inertial mass is developed. In this system, the dominant wave period is calculated by the Fast Fourier Transform using the wave amplitude and the inertial mass is adjusted accordingly. Numerical results showed that the proposed system responded appropriately to the wave period changes and works better than the TIM system.

Free Research Field

構造物の振動制御

Academic Significance and Societal Importance of the Research Achievements

本研究では新たな可動物体型の波力発電装置を提案しており、脱炭素社会を目指す現代社会において大きな社会的意義をもつと考えれる。
また、本研究でも用いられている同調回転慣性質量機構は本来、地震動を受ける建築・土木構造物の制振技術として提案されているものであり、その技術を波力発電装置へ応用することは既存の学問分野を超えた学際的な研究と考えられ、その学術的にも大きな可能性を示したと考えられる。