Tidal Turbine Output Control via Submarine Cable Voltage
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Solution Overview
Problem
The challenge in hydroelectric tidal power generation is to accurately control the output of submarine turbine generators while maintaining efficient operation and extending the lifespan of transmission systems, particularly in harsh marine environments where regular maintenance is costly and impractical.
Innovation Solution
A method of remotely controlling the output power of offshore tidal hydroelectric turbine generators by varying the line voltage of submarine power cables to adjust the rotational speed of the turbines, maintaining a minimum voltage level during reduced tidal power conditions to monitor fault conditions and reduce electrical stress on the cables.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the line voltage of submarine power cables is varied to control turbine rotational speed and optimize power generation, then power control efficiency is improved, but electrical stress on cables increases reducing their lifespan
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the line voltage of submarine power cables to control turbine rotational speed. The voltage is varied within specific ranges (e.g., 280-320V for normal operation, reduced to 200-280V during low tidal power conditions) to optimize power generation while preventing excessive electrical stress that would reduce cable lifespan. This controlled parameter variation resolves the contradiction between power control efficiency and cable durability.
2Productivity
If the line voltage is reduced during low tidal power periods, then power generation is optimized for available tidal energy, but fault detection capability in the transmission system is lost
Solution Approach 1:
The patent implements periodic action by maintaining a minimum voltage level (e.g., 200-280V) during low tidal power periods instead of completely reducing voltage. This periodic maintenance of voltage enables continuous fault detection capability in the transmission system while still optimizing power generation for available tidal energy. The system alternates between voltage reduction for optimization and minimum voltage maintenance for monitoring, resolving the contradiction between power generation efficiency and fault detection.
3Productivity
If voltage is continuously varied to track optimal tip-speed ratio, then power generation efficiency is maximized, but electrical stress on cables increases reducing their operational life
Solution Approach 1:
The patent applies partial action by varying voltage within optimized ranges rather than continuously across the full possible range. During low tidal power conditions, voltage is reduced to a specific partial range (200-280V) rather than being completely reduced or continuously varied. This partial voltage variation maintains sufficient power generation efficiency while limiting electrical stress on cables, thereby extending their operational life.
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 allows for efficient power control, extends the lifespan of submarine power cables, and enables early detection of faults, reducing maintenance costs and ensuring reliable operation by maintaining a stable voltage during low tidal power periods.
Implementation Method 1
using at least one submarine power cable transmitting power from said at least one turbine generator to said substation
Implementation Method 2
the method comprising the step of varying the line voltage of the submarine power cable to control the rotational speed of the at least one turbine generator
Data Source
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AI summary
There is described a method for controlling the output of a tidal hydroelectric turbine (10) generator from a remote location, with the need for control circuitry to be housed local to the generator. The rotational speed of the turbine (10), and consequently the output power level of the generator, is controlled by varying the transmission line voltage of the submarine power cable (24) connecting the off-shore turbine with an on-shore substation (22).