Wave Energy Converter Phasing for Constant-Power Microgrids
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wave energy converter arrays face inefficiencies in energy capture and require complex energy storage systems due to variable wave inputs, necessitating advanced power electronic and control system designs to stabilize and integrate renewable energy into the grid.
Innovation Solution
A power packet network is implemented for wave energy converter arrays, where each converter is physically spaced and phased to minimize energy storage requirements, leveraging the WEC location to optimize power capture and quality by injecting phased electrical power into a collection bus, utilizing AC RLC circuits and AC to AC converters to emulate an N-phase AC system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wave energy converters are closely spaced to maximize energy capture, then energy capture efficiency is improved, but power quality and grid stability deteriorate due to variable and unsynchronized power output
Solution Approach 1:
The patent divides the wave energy converter array into multiple independently controlled units, each with its own power electronics interface. This segmentation allows each WEC to operate independently and contribute power at different phases, maintaining high energy capture while enabling individual power quality control through phase-shifting capabilities of the power electronic converters.
Solution Approach 2:
The patent employs power electronic converters that can dynamically change the phase angle of power injection from each WEC into the collection bus. By adjusting the phase parameter of each converter, the system maintains constant total power output and stable bus voltage despite variable wave conditions, thus improving power quality while maintaining energy capture efficiency.
2Ease of operation
If conventional power converter designs are used for voltage conversion, then voltage conversion is achieved, but device complexity increases due to additional energy storage systems and control components required for grid stability
Solution Approach 1:
The patent designs power electronic converters that perform multiple functions simultaneously: voltage conversion, phase shifting, power quality regulation, and grid stability maintenance. This multi-functionality eliminates the need for separate energy storage systems and control components, reducing overall device complexity while maintaining full voltage conversion capability and grid stability.
Solution Approach 2:
The power electronic converters are designed to automatically regulate power output and maintain grid stability without requiring external energy storage systems. The converters self-adjust their operation to provide constant power output and maintain bus voltage stability, making the system self-sufficient and reducing complexity by eliminating separate control components.
3Ease of manufacture
If wave energy converters operate independently without phasing, then installation is simplified, but energy storage requirements increase to maintain constant bus voltage
Solution Approach 1:
The patent maintains independent WEC units for simple installation but segments the power injection into different phases through power electronic converters. This allows each WEC to be installed independently while the converters create phased power injection patterns that reduce total energy storage requirements by smoothing power fluctuations through phase diversity.
Solution Approach 2:
The patent introduces phase angle as a controllable parameter in power injection without changing the physical installation configuration. By adjusting the phase parameter of each converter, the system reduces power fluctuations and minimizes energy storage requirements while maintaining installation simplicity.
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
This approach minimizes energy storage needs while maintaining constant bus voltage, enhancing power quality and capture efficiency, and allows for seamless integration into the grid, reducing complexity and costs.
Implementation Method 1
each wave energy converter converts incoming water wave motion to electrical power
Implementation Method 2
a buoy that converts the incoming water wave motion to a mechanical motion and a power take-off that converts the mechanical motion to an electrical power
Implementation Method 3
each of the wave energy converters is physically spaced with respect to each other and the incoming water wave such that the electrical power injected into the collection bus from each of the wave energy converters is phased with respect to each other
Data Source
AI summary
One of the biggest challenges for all renewable energy sources (RES) is that they are variable power generators which will require reactive power or energy storage systems (ESS) to provide reliable power quality (ideally power factor of one) at the power grid generation side. The present invention is directed to a power packet network (PPN) for integrating wave energy converter (WEC) arrays into microgrids. Specifically, an array of WECs can be physically positioned such that the incoming regular waves will produce an output emulating an N-phase AC system such that the PPN output power is constant. ESS requirements are thereby minimized whilst maintaining grid stability with high power quality. This will enable RES integration onto a future smart grid for large-scale adoption and cost reduction while preserving high efficiency, reliability, and resiliency.