Offshore Wind Turbine Vibration Damping via Rotor Tumble Mode
Solution Overview
Problem
Offshore wind turbines experience undesirable vibrations due to wave forces acting on the foundation, which can lead to damage and premature aging, especially when the turbine is at a standstill.
Innovation Solution
Operating the wind turbine in a 'tumble mode' with a constant blade angle, adjusting the rotor's idle speed to induce sufficient aerodynamic damping, and actively monitoring and controlling parameters like wind speed and vibration amplitude to stabilize the support structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the wind turbine is operated at a standstill, then energy consumption is minimized, but vibrations are excited in the support structure due to wave forces acting on the foundation
Solution Approach 1:
The patent applies aerodynamic damping through controlled rotor rotation to counteract harmful vibrations in the support structure. The rotor is spun at a specific idle speed to generate aerodynamic forces that dampen the vibrations excited by wave forces on the foundation, resolving the contradiction between energy minimization and vibration reduction.
Solution Approach 2:
The patent changes the operational parameters of the wind turbine by adjusting the rotor speed to a specific idle range (1-10 rpm) and setting the blade pitch angle to a predetermined value. This parameter adjustment enables aerodynamic damping without significant energy consumption, addressing both the energy minimization and vibration reduction requirements.
2Object-affected harmful factors
If the rotor is spun at high speed to generate aerodynamic damping, then vibrations are reduced, but energy consumption and torque increase
Solution Approach 1:
The patent optimizes the rotor speed parameter to a low idle range (1-10 rpm) that is sufficient to generate aerodynamic damping effects while minimizing energy consumption. This parameter optimization resolves the contradiction between vibration reduction and energy usage by finding the minimum effective operating point.
Solution Approach 2:
The patent maintains continuous rotor rotation at a low idle speed to provide ongoing aerodynamic damping without the need for high-speed operation. This continuous low-level operation achieves vibration reduction while keeping energy consumption minimal, avoiding the need for intermittent high-energy interventions.
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 method effectively reduces vibrations in the support structure by leveraging aerodynamic damping, minimizing mechanical effects from waves and preventing damage, while maintaining low torque and energy consumption.
Implementation Method 1
it has been recognized that the effect of aerodynamic damping can be utilized by guiding the wind energy installation in tumble mode in order to reduce vibrations in the support structure
Implementation Method 2
The damping of the vibrations is based on the movement of the rotor caused by the vibration of the supporting structure in the air mass of the flow tube, which is subject to the inertial effect and is generated by the spinning operation
Data Source
Figure 1
Figure 2a~2b
Figure 3a~3b
AI summary
The invention relates to a method for operating a wind turbine (1), in particular a wind turbine (1) founded in a body of water (14), wherein the wind turbine (1) comprises a support structure (2, 13) and a rotor (4, 5) arranged on the support structure (2, 13), the rotor (4, 5) having a rotor blade (5). The invention further relates to a wind turbine (1), in particular a wind turbine (1) founded in a body of water (14), with a support structure (2, 13) and a rotor (4, 5) comprising a rotor blade (5). The invention is characterized in that, in order to reduce the vibrations of the support structure (2, 13) generated by mechanical forces acting on it, the wind turbine (1) is operated in a spin cycle.