Wind Turbine Electrolyser Switching for Low-Power Torque Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in wind turbine generators is to control torque effectively during low power situations, particularly when the voltage across the electrolyser is low, leading to hydrogen cross-over and safety hazards, and reducing the efficiency of green hydrogen production from renewable energy sources.
Innovation Solution
The solution involves a wind turbine system with selectively operable electrical conductors connecting electrolysis cells to a rectifier, allowing for optimized operation based on available power and condition, enabling better torque control and reducing hydrogen cross-over by varying the number of electrolysis cells in use and their location within the stack.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the voltage across the electrolyser is low, then the current through the electrolyser is drastically reduced, but the torque in the generator drops significantly leading to unbalanced loads and improper control
Solution Approach 1:
The electrolyser stack is divided into multiple independently controllable sections, each with its own electrical connectors. This segmentation allows the system to selectively activate only the number of electrolysis cells needed to match available power, preventing torque drops and maintaining load balance during low wind conditions.
Solution Approach 2:
The system dynamically adjusts the number of active electrolysis cells based on real-time power availability from the wind turbine generator. By selectively connecting or disconnecting electrolysis cell sections through controllable electrical conductors, the system adapts to varying wind conditions while maintaining stable generator torque and balanced loads.
2Productivity
If the electrolyser is operated at low loads, then potentially useful green energy can be utilized, but hydrogen cross-over may result in an explosive gas mixture being formed
Solution Approach 1:
Instead of operating the entire electrolyser stack at low load (which risks hydrogen cross-over), the system activates only the necessary number of electrolysis cell sections to match available power. This partial operation ensures each active cell operates at adequate current density, preventing hydrogen cross-over while still utilizing low wind energy for safe hydrogen production.
Solution Approach 2:
The system changes the operational parameters by adjusting the number of active electrolysis cells based on power availability. When power is low, fewer cells are activated, ensuring each operates above the minimum current density threshold that prevents hydrogen cross-over, thus maintaining safety while enabling green hydrogen production across a wider range of wind conditions.
3Loss of energy
If an electrolyser is directly connected to the generator in a DC-coupled connection, then cost of convertor and electrical efficiency are improved, but sudden low generator torque leads to unbalanced loads and unwanted noise
Solution Approach 1:
The electrolyser is segmented into multiple independently controllable sections, allowing the system to maintain stable torque by adjusting the number of active cells rather than allowing torque to fluctuate. This segmentation enables the DC-coupled connection to maintain high electrical efficiency while avoiding the unbalanced loads and noise that would result from sudden torque changes.
4Productivity
If the number of electrolysis cells in use is increased, then more hydrogen can be produced, but the torque control becomes more difficult during low power situations
Solution Approach 1:
The system dynamically adjusts the number of active electrolysis cells to match power availability, making torque control easier during low power situations. When wind power is low, fewer cells are activated to prevent torque drops; when power is abundant, more cells are activated to increase hydrogen production. This dynamic adjustment simplifies torque control while optimizing productivity across all operating conditions.
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 maintains generator torque at acceptable levels, allows for efficient operation of electrolysis cells during low power conditions, and reduces the risk of hydrogen cross-over, enabling the use of low wind energy for green hydrogen production while prolonging electrolyser life through balanced usage.
Implementation Method 1
Hydrogen production via water electrolysis
Data Source
AI summary
A wind turbine generator is connected to a rectifier which is directly DC coupled to one or more electrolysers. The, or each, electrolyser comprises a plurality of electrolysis cells arranged in one or more stacks, each electrolysis cell comprising a pair of electrodes, and each stack of electrolysis cells comprising at a plurality of electrical connectors. Each electrical connector is in electrical contact with an electrode of an electrolysis cell. The electrical connectors are electrically connectable to the rectifier by a network of selectively operable electrical conductors which are configured so that some or all of the electrolysis cells are operable in dependence on the operative condition of the selectively operable electrical conductors. A method for controlling torque in a wind turbine generator comprising controlling the operation of the selectively operable electrical conductors in dependence on a generator output characteristic.