Variable-Ballast Wave Energy Converter for Wide-Spectrum Tuning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wave Energy Converters (WECs) face challenges in efficiently extracting energy from the dynamic and complex frequency spectrum of ocean waves due to their superposition of countless frequency and amplitude waves, requiring a system that can adapt to varying conditions on a second or sub-second time scale for maximum energy extraction.
Innovation Solution
A linear, universal modular absorber is introduced, comprising an actuated subassembly and a reference subassembly with a direct drive linear machine, capable of converting linear mechanical motion into electrical energy, and featuring a pressurization system to maintain or modify pressure within the chamber, enhancing mechanical stiffness and power maximization, while adapting to various mechanical interactions with waves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a WEC uses a simple controller with mechanical damping coefficient to maximize power from dominant wave frequency, then the control system is simple and easy to implement, but it cannot efficiently extract energy from the wide frequency spectrum of ocean waves
Solution Approach 1:
The patent implements variable ballast weights that can be dynamically adjusted to change the natural frequency of the floating body, allowing the system to adapt to different dominant wave frequencies and maximize energy extraction across a wide frequency spectrum rather than being fixed to a single frequency
Solution Approach 2:
The system changes the physical parameters of the WEC by adjusting ballast weights, which modifies the mass and natural frequency of the floating body to match varying wave conditions, enabling efficient energy extraction from different frequency components of ocean waves
2Productivity
If a WEC is designed to extract energy from a wide frequency spectrum with rapid adaptation, then energy extraction efficiency is maximized, but the system complexity and engineering design burden increase significantly
Solution Approach 1:
The patent divides the ballast system into separate, modular weight components that can be independently adjusted, allowing the system to be tuned for different wave frequencies without requiring complete system redesign, thus managing complexity through modular segmentation
Solution Approach 2:
The variable ballast system serves multiple functions: it adjusts natural frequency for different wave conditions, provides ballasting for floating stability, and enables the single WEC design to handle a wide frequency spectrum, reducing the need for multiple specialized designs
3Ease of manufacture
If a modularized PTO system is designed to be universally applicable for a wide range of relative mechanical motions, then engineering and design efforts are reduced, but the system must accommodate greater variability in mechanical characteristics
Solution Approach 1:
The modular PTO system is designed with adjustable parameters including variable ballast weights that can be configured to match different mechanical characteristics of floating bodies and wave conditions, allowing a single modular design to adapt to various applications without requiring custom engineering for each case
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The modular absorber effectively converts wave energy into electrical energy by exploiting relative motion between two bodies, providing mechanical stiffness and power maximizing control, and adapting to diverse wave conditions, thus enhancing energy extraction efficiency and reducing engineering redundancy.
Implementation Method 1
containing a direct drive linear machine for converting linear mechanical motion into electrical energy
Implementation Method 2
featuring a pressurization system to maintain or modify pressure within the chamber, enhancing mechanical stiffness
Implementation Method 3
an actuating body provides an input force, in this case the buoyancy and hydrodynamic excitation through the drag of floating body in the wave orbital
Implementation Method 4
hydrodynamic excitation through the drag of floating body in the wave orbital
Data Source
AI summary
A two-body wave energy converter utilizing a linear, universal modular absorber. A linear module, contains a direct drive linear machine for converting linear mechanical motion into electrical energy. The linear module is connected between two oscillating mechanical bodies, exploiting their relative motion. A wave activated floating body follows the wave motion, while a reaction body is tethered to a mass on the seabed providing a stable kinematic reference in operational waves. In large waves, the mass on the seabed lifts, providing heave compliance to the whole wave energy converter reducing ultimate loads in survival wave conditions.