Wind Turbine Pitch Control for Flutter Suppression Without Yawing
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Solution Overview
Problem
Large wind turbines face increased flutter risks due to larger impeller diameters and tower heights, and existing methods for flutter suppression, such as changing the nacelle-wind direction angle and pitch angle, require significant energy that small diesel generators cannot provide during power grid failures.
Innovation Solution
A method and device for flutter suppression in wind turbines that utilize a speed-controlled and pitch-angle-sequence-controlled pitching scheme to adjust pitch angles based on the nacelle-wind direction angle, without requiring yawing, using a small diesel generator for power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If yawing and pitching actions are performed simultaneously to suppress flutter, then flutter suppression effectiveness is improved, but energy consumption exceeds the capacity of small diesel generators during power grid failures
Solution Approach 1:
The invention extracts and removes the yawing action from the flutter suppression system, retaining only the pitching action. This is achieved by controlling pitch angles according to a pitch angle sequence that is determined based on the nacelle-wind direction angle, eliminating the need for simultaneous yawing and pitching operations while still achieving effective flutter suppression within limited energy constraints
Solution Approach 2:
The invention changes the control parameters from simultaneous yaw and pitch control to pitch-only control with sequence-based pitch angle adjustment. The pitch angle sequence is dynamically determined based on the nacelle-wind direction angle, transforming the control strategy to achieve flutter suppression through parameter optimization rather than multi-action coordination
2Speed
If pitch angles are regulated according to rotor speed to maintain speed within preset range, then rotor speed stability is improved, but the complexity of control logic increases
Solution Approach 1:
The invention implements feedback control by continuously monitoring rotor speed and adjusting pitch angles based on the deviation from the preset speed range. The control system detects rotor speed, compares it with the target range, and automatically adjusts pitch angles to maintain speed stability, creating a closed-loop feedback mechanism that simplifies complex control logic through systematic error correction
Solution Approach 2:
The invention introduces dynamic adjustment of pitch angles based on real-time rotor speed conditions. The pitch angle sequence is dynamically modified according to whether rotor speed is above or below the preset range, enabling the system to adapt its control strategy to changing operating conditions while maintaining manageable control complexity through rule-based dynamic responses
Data Source
AI summary
A wind turbine flutter suppression method includes: determining a nacelle-wind direction angle between a wind direction and a nacelle direction; and determining a pitching method for changing pitch angles according to the nacelle-wind direction angle. The pitching method includes a speed-controlled pitching scheme and a pitch-angle-sequence-controlled pitching scheme. The speed-controlled pitching scheme includes regulating pitch angles of blades of the wind turbine according to a rotor speed of the wind turbine to keep the rotor speed within a preset speed range until flutter of the wind turbine is suppressed. The pitch-angle-sequence-controlled pitching scheme includes performing a pitching operation on the pitch angles of the blades of the wind turbine according to preset pitching rules until the flutter of the wind turbine is suppressed.