Wind Turbine Generator Air Gap Control for Noise Reduction
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Solution Overview
Problem
Wind power installations with gearless generators produce unwanted noise due to mechanical vibrations between the rotor and stator, which can exceed predefined noise limits, leading to unfavorable operating points when attempting to reduce rotational speed.
Innovation Solution
A method is proposed to control the wind power installation by adjusting the air gap thickness between the rotor and stator, which changes with temperature, using a control regulation that sets a relationship between rotational speed and power output based on the air gap thickness to minimize noise levels, allowing for targeted adjustments to operating points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the rotational speed of the generator is decreased to reduce noise levels, then the noise emission is reduced, but the operating point becomes unfavorable and power output decreases
Solution Approach 1:
The patent applies parameter changes by adjusting the air gap thickness between rotor and stator to modify the magnetic interaction characteristics. By changing the air gap parameter, the system can reduce mechanical vibrations and noise emission without necessarily decreasing rotational speed, thus avoiding the unfavorable operating point that would result from simple speed reduction.
Solution Approach 2:
The control regulation is selected or set in a manner which is dependent on the air gap thickness, making the control system adaptive. This dynamic adjustment allows the system to optimize the relationship between rotational speed and power output based on current air gap conditions, enabling noise reduction while maintaining favorable operating points.
2Object-affected harmful factors
If the air gap thickness is increased to reduce mechanical vibrations, then the noise level decreases, but the magnetic interaction efficiency is reduced
Solution Approach 1:
The system dynamically adjusts the control regulation based on the air gap thickness. When the air gap increases (due to thermal expansion), the control regulation is modified to compensate for the reduced magnetic interaction efficiency, thereby maintaining power output while benefiting from the reduced mechanical vibrations and noise.
Solution Approach 2:
By intentionally modifying the air gap thickness parameter (through thermal management or mechanical adjustment), the system changes the magnetic field distribution to reduce mechanical vibrations and noise, while the control regulation compensates for efficiency changes to maintain overall power output.
3Object-affected harmful factors
If the control regulation is changed to reduce noise, then the noise emission is reduced, but the operating point becomes unfavorable
Solution Approach 1:
The control regulation is made dynamic and adaptive by selecting or setting it in a manner which is dependent on the air gap thickness. This allows the system to automatically adjust to changing conditions without manual intervention, maintaining favorable operating points while reducing noise emission through coordinated adjustments of rotational speed and power output.
Solution Approach 2:
The system uses feedback from the air gap thickness measurement to continuously adjust the control regulation. This closed-loop control ensures that noise reduction measures do not push the system into unfavorable operating points, as the control parameters are automatically optimized based on real-time air gap 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 effectively reduces noise levels by adjusting the air gap thickness and corresponding control regulations, maintaining optimal operating points while adhering to noise limits, even under varying wind conditions.
Implementation Method 1
If the stator heats up here, it can expand as a result and can increase in size in comparison with the rotor. The air gap thickness is increased as a result.
Data Source
AI summary
Provided is a method for controlling a wind power installation, the wind power installation having a generator for the generation of electric current, the generator having an air gap with a variable air gap thickness, the wind power installation being controlled in a part load range by means of a control regulation, the wind power installation being controlled in a manner which is dependent on the air gap thickness, the control regulation being selected or set in a manner which is dependent on the air gap width.