Point Absorber PTO Control for Broad-Band Wave Energy Capture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional sea wave energy harvesting systems are inefficient and expensive due to their narrow operating band, inability to capture energy across varying wave conditions, and high energy storage needs, leading to underutilization of sea wave energy.
Innovation Solution
A wave energy system with a power takeoff drum, generator, mooring belt, and control system that dynamically adjusts to sea wave cycles, utilizing a generator as both a motor and a generator, and incorporating a pneumatic return spring assembly and braking system to optimize energy capture across varying wave conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional sea wave energy harvesting systems are designed to harvest energy in particular sea wave conditions, then energy harvesting efficiency is improved for those specific conditions, but the system has a narrow operating band and cannot efficiently harvest energy when sea wave conditions vary
Solution Approach 1:
The patent applies dynamics by making the mooring belt system adjustable and adaptable to varying wave conditions. The belt can be dynamically tensioned and retensioned to maintain optimal operating conditions across different wave heights and frequencies, transforming a static system into one that adapts to changing environmental parameters.
Solution Approach 2:
The system changes physical parameters of the mooring belt (tension, length, configuration) in response to varying wave conditions. By adjusting these parameters, the system maintains efficient energy harvesting across a broad spectrum of wave conditions rather than being optimized for a single set of parameters.
2Device complexity
If traditional sea wave energy harvesting systems operate with narrow operating bands, then system design is simplified for specific conditions, but energy storage requirements increase to provide continuous uninterrupted power
Solution Approach 1:
The patent achieves continuity of useful action by enabling the system to operate efficiently across all wave conditions without interruption. The adaptive mooring belt system ensures continuous energy harvesting from varying waves, eliminating the need for large energy storage systems to bridge periods of low wave activity.
Solution Approach 2:
The system performs preliminary action by pre-tensioning the mooring belt and positioning components to optimize energy capture before waves arrive. This proactive configuration allows the system to immediately begin harvesting energy when wave conditions change, maintaining continuous operation.
3Device complexity
If traditional sea wave energy harvesting systems do not capture energy from the entire wave cycle, then system design is simpler, but energy harvesting efficiency is reduced
Solution Approach 1:
The patent implements continuity of useful action by capturing energy throughout the entire wave cycle. The mooring belt system is configured to harvest energy during both the rising and falling phases of waves, ensuring continuous energy conversion rather than operating only during specific portions of the wave cycle.
Solution Approach 2:
The system utilizes periodic action by synchronizing energy harvesting with the periodic nature of wave cycles. The mooring belt tensioning and energy conversion mechanisms are timed to match the rhythmic rise and fall of waves, maximizing energy capture from each complete wave period.
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 system efficiently captures and converts wave energy across changing conditions, eliminating the need for end stops and reducing energy storage requirements, thereby enhancing energy production and system efficiency.
Implementation Method 1
a pneumatic return spring assembly having a pneumatic return spring connecting to a spring return belt
Implementation Method 2
a generator including a rotor rotationally coupled directly, or indirectly with a gear ratio to the power takeoff drum, a control system controlling the generator to generate electricity during upward portions of sea wave cycles
Implementation Method 3
a braking system connected to the power takeoff drum, the braking system comprised of a braking disc, braking calipers, and braking pads
Data Source
AI summary
A system and method for a for a wave energy converter device that is an axisymmetric point absorber which operates in a tension only condition over a large stroke that can operate in the given wave environment so as to eliminate the need for end stops in normal operation whereby the wave energy converter device has a floating hull with an interior Power Take Off (PTO) that uses an impedance control scheme for impedance matching with the wave environment in which it is deployed so as to maximize electrical power output as compared with a passively operating device of similar size.