Wind Turbine Drivetrain Vibration Damping via Segmented Speed Sensing
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Solution Overview
Problem
Newer, larger wind turbines face challenges in accurately detecting drivetrain vibrations due to lower frequencies, leading to potential equipment overloads from inappropriate torque modulation.
Innovation Solution
Implementing high fidelity encoders at multiple locations along the drivetrain to measure speed errors between the rotor and generator, using these errors to generate torque deviation signals to dampen vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If bandpass filter is used to detect drivetrain vibrations from generator speed, then vibration detection is enabled, but measurement precision deteriorates due to lower frequencies in newer, larger wind turbines
Solution Approach 1:
The patent divides the drivetrain into multiple segments with sensors at different locations (rotor shaft, gearbox input, gearbox output, generator shaft). Each segment's speed is measured independently, and vibrations are detected by comparing the segmented speed measurements rather than using a single bandpass filtered signal, thereby improving measurement precision without increasing filter complexity
Solution Approach 2:
The patent introduces speed measurements at intermediate locations (rotor shaft and gearbox) as mediators between the generator speed and actual drivetrain vibrations. These intermediary measurements provide additional information that helps accurately detect vibrations without requiring complex bandpass filtering of the generator speed signal
2Ease of operation
If bandpass filtered generator speed is used as proxy for drivetrain vibration, then control function is simplified, but reliability deteriorates when filtered speed is not a good proxy
Solution Approach 1:
The patent implements feedback by continuously comparing speed measurements from multiple locations and using the differences to detect vibrations. The control system receives feedback from segmented speed measurements and adjusts torque modulation accordingly, ensuring reliable vibration detection without relying on a potentially inaccurate single-point proxy
Solution Approach 2:
The patent segments the drivetrain speed measurement into multiple independent measurements at different locations. This segmentation allows the system to maintain control simplicity while improving reliability by using the collective information from all segments rather than relying on a single filtered signal that may not accurately represent actual vibrations
3Productivity
If torque modulation is applied based on inaccurate vibration proxy, then control action is implemented, but harmful effects occur through equipment overload
Solution Approach 1:
The patent performs preliminary action by measuring speeds at multiple locations continuously and comparing them to detect vibrations before applying torque modulation. This preliminary detection ensures that torque modulation is based on accurate vibration information, preventing harmful equipment overload while maintaining prompt control response
Solution Approach 2:
The drivetrain system uses its own operational data (speed measurements from various points) to self-diagnose vibration conditions and automatically adjust torque modulation. This self-service approach ensures control actions are based on actual system state, preventing harmful effects from inaccurate proxies while maintaining rapid response
Data Source
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AI summary
A method for damping drivetrain vibrations of a wind turbine. The drivetrain has, at least, a rotor and a generator. The method includes receiving a first rotational speed signal at a first location along the drivetrain, the first rotational speed signal being a proxy for rotor speed of the rotor. The method also includes receiving a second rotational speed signal at a second location along the drivetrain, the second location being downwind from the first location, the second rotational speed signal being a proxy for generator speed of the generator. Further, the method includes determining a speed error based on a comparison of the first and second rotational speed signals. Moreover, the method includes determining a torque deviation signal for the wind turbine configured to dampen the drivetrain vibrations when the speed error exceeds a first speed threshold. In addition, the method includes applying the torque deviation signal to the generator to dampen the drivetrain vibrations.