Parametric Wave Energy Conversion With Depth-Adjustable Subsea Paravane
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Solution Overview
Problem
Conventional wave energy converters (WECs) face challenges in operating under varying wave conditions, including exceeding capacity limits and not accounting for ocean currents, leading to shutdowns and interrupted energy capture, and inefficiencies due to reacting to only heave-up forces.
Innovation Solution
A wave energy converter system with a depth-adjustable paravane and a power take-off (PTO) mechanism, controlled by a controller to regulate energy transfer, allowing operation across different wave conditions and utilizing both heave-up and heave-down forces for efficient energy harvesting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a WEC is shut-down and placed into survival mode when approaching maximum operating conditions, then the mechanical interface and PTO are protected from damage, but wave energy capture is interrupted
Solution Approach 1:
The paravane depth is made dynamically adjustable through a depth control system that can raise or lower the paravane relative to the water surface. When wave conditions approach maximum operating conditions, the paravane is raised to reduce the mechanical interface area and forces, allowing the WEC to remain in operation rather than shutting down. This dynamic adjustment resolves the contradiction by protecting the system while maintaining continuous energy capture.
2Stability of the object's composition
If a buoy or positive buoyant WEC is used, then the structure provides stability and浮力, but it only reacts to heave-up forces
Solution Approach 1:
A ballast system is implemented to counterbalance the buoyant force, enabling the paravane to react to both heave-up and heave-down forces. The ballast weight allows the system to utilize the full wave cycle for energy generation, doubling the theoretical efficiency compared to systems that only capture heave-up forces. This resolves the contradiction by maintaining structural stability through controlled ballast while maximizing energy capture from both upward and downward wave motions.
3Device complexity
If the paravane depth is fixed, then the mechanical interface is simplified, but the WEC cannot adapt to varying wave conditions
Solution Approach 1:
A depth control system with actuators is introduced to dynamically adjust the paravane depth based on real-time wave conditions. The controller monitors wave parameters and automatically positions the paravane at optimal depths to maintain operation within maximum operating conditions while capturing maximum energy. This dynamic capability resolves the contradiction by adding adaptability without permanently complicating the mechanical interface.
4Device complexity
If the WEC operates only in a fixed direction, then the mechanical interface is simplified, but it cannot harvest energy from waves approaching from different directions
Solution Approach 1:
A rotational actuator system is implemented to dynamically adjust the azimuth orientation of the paravane. The controller monitors wave direction and rotates the paravane to face incoming waves from any direction, enabling continuous energy harvest regardless of wave approach angle. This dynamic directional adjustment resolves the contradiction by adding versatility while maintaining a relatively simple mechanical interface through modular actuation.
Data Source
AI summary
A system for converting wave energy into electricity is provided. The system includes a wave energy mechanical interface, a power take off coupled with the wave energy mechanical interface, and a generator coupled with the power take off. A controller is coupled with the power take off. The controller is configured to regulate impedance of energy transferred from the power take off to the generator.