Wind Turbine Tower Deflection Control for Power Transitions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for controlling wind energy installations when there is a change in nominal power value are inefficient, as they do not reliably implement changes within a predetermined time interval, especially considering non-linear relationships between operating parameters and power targets.
Innovation Solution
A method that calculates a control function for operating parameters based on the thrust of the rotor, using a parameterized time function for tower deflection to minimize load on the wind energy installation, allowing for non-linear adjustments to achieve the new power target within the specified time frame.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a simple ramp approach with constant rise or fall is used to change power target value, then the control implementation is simple, but the actual power value cannot reliably reach the new target within the predetermined time interval due to non-linear relationships between operating parameters and power target
Solution Approach 1:
The patent transforms the control approach from directly controlling operating parameters (pitch angle, torque) to controlling the tower deflection parameter. By calculating a control function based on tower deflection that accounts for the tower's natural frequency and damping, the system reliably achieves the new power target within the predetermined time interval while maintaining simple implementation through a unified control parameter.
2Ease of operation
If operating parameters are adjusted linearly to achieve new target power value, then the control method is straightforward, but the mechanical load on the wind turbine tower is not minimized and may cause excessive vibrations
Solution Approach 1:
The patent changes the control parameter from operating parameters (pitch angle, torque) to tower deflection. The control function is designed to minimize the mechanical load on the tower by accounting for the tower's natural frequency and damping characteristics, thereby reducing vibrations and mechanical stress while maintaining straightforward control implementation.
Solution Approach 2:
The patent explicitly considers the tower's natural frequency and damping when designing the control function for tower deflection. By shaping the deflection profile to avoid resonant frequencies and account for damping characteristics, the system minimizes mechanical vibrations and load on the tower structure during power transitions.
3Device complexity
If the tower deflection is not considered in the control function, then the control system is simpler, but the mechanical vibrations and load on the tower structure increase
Solution Approach 1:
The patent introduces tower deflection as the control parameter and incorporates the tower's natural frequency and damping into the control function. This approach maintains relatively simple control system architecture while significantly improving tower structure stability by minimizing vibrations and mechanical load during power transitions.
Data Source
Figure 1
Figure 2
AI summary
A method for controlling a wind turbine comprising a tower and a motor equipped with at least one rotor blade adjustable in its blade pitch angle, when a power setpoint changes, wherein the change in the power setpoint occurs within a predetermined time interval and by controlling one or more power-determining operating parameters, characterized by the following method steps: - A parameterized time function of the tower deflection is defined for the predetermined time interval, wherein a series of boundary conditions are defined for the parameterized time function of the tower deflection, - a thrust force of the rotor on the tower of the wind turbine is determined for the parameterized time function of the tower deflection, and - a function for controlling the operating parameter or parameters is calculated from the thrust force of the rotor.