Wind Turbine Generator Torque Modulation for Gearbox Noise
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wind turbines generate structure-borne vibrations and associated noise, particularly from gear tooth meshing in the gearbox, which can exceed allowable noise limits and disturb neighbors or animal life.
Innovation Solution
A method for controlling generator operation by obtaining measures of rotational speed and gearbox vibrations, generating a torque modulating signal to match and cancel out gearbox vibrations, adjusting the phase and amplitude to minimize resultant vibrations, and injecting the adjusted signal into the generator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the generator operates at high power output, then energy production is improved, but gearbox vibrations from gear tooth meshing increase and generate excessive noise
Solution Approach 1:
The patent applies preliminary anti-action by generating a torque modulating signal that creates vibrations in the generator shaft which are designed to counteract and cancel out the gearbox vibrations from gear tooth meshing. The controller pre-calculates and applies this counteracting torque modulation before the harmful vibrations fully manifest, thereby reducing noise while maintaining power output.
Solution Approach 2:
The patent utilizes mechanical vibration by intentionally modulating the torque on the generator shaft at frequencies that match the gearbox vibration frequencies. This creates controlled vibrations in the generator that interfere destructively with the unwanted gearbox vibrations, reducing the overall noise while preserving energy production capability.
2Object-generated harmful factors
If torque modulation is applied to reduce gearbox vibrations, then noise is reduced, but generator control complexity increases
Solution Approach 1:
The patent implements feedback by continuously monitoring the actual generator shaft angle and comparing it with the estimated shaft angle derived from the torque modulating signal. The controller uses this feedback information to adjust and optimize the torque modulation parameters, ensuring effective vibration reduction while adapting to varying operating conditions, thereby managing control complexity through intelligent adaptation.
Solution Approach 2:
The patent replaces direct mechanical vibration damping mechanisms with an electrical control approach. Instead of using physical dampers or mechanical modifications to the gearbox, the system uses electronic torque modulation signals applied to the generator, substituting complex mechanical solutions with more controllable electrical and computational methods.
3Object-generated harmful factors
If the phase angle and amplitude of torque modulating signal are continuously adjusted to minimize vibrations, then noise reduction is improved, but control precision requirements increase
Solution Approach 1:
The patent applies self-service by enabling the generator and gearbox system to automatically adjust its own vibration characteristics through torque modulation. The system uses its own operational parameters (shaft angle, power output) to generate the corrective torque signals, making the system self-regulating and reducing the need for external precise measurement and control infrastructure.
Solution Approach 2:
The patent utilizes parameter changes by dynamically adjusting the phase angle and amplitude of the torque modulating signal based on real-time operating conditions. The controller modifies these parameters to match the varying vibration characteristics of the gearbox across different power outputs, maintaining effective noise reduction without requiring fixed high-precision settings.
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
Reduces noise generated by the wind turbine power train by minimizing vibrations from gear tooth meshing, thereby reducing overall noise emissions.
Implementation Method 1
generating a torque modulating signal to match and cancel out gearbox vibrations
Implementation Method 2
adjusting the phase and amplitude to minimize resultant vibrations
Data Source
AI summary
A method for controlling operation of a generator for a wind turbine is disclosed. At least one amplitude of a harmonic in the gearbox vibrations is determined. A torque modulating signal for the generator is generated. A phase angle and the amplitude are adjusted during operation of the generator, until a minimum in amplitude of a resultant vibration is reached, thereby obtaining an adjusted torque modulating signal. The adjusted torque modulating signal is injected into the generator, resulting in the resultant vibration of vibrations of the gearbox and vibrations of the generator, corresponding to the harmonic in the gearbox vibrations, being reduced.