Floating Wind Turbine Pitch Control Vibration Detection
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Solution Overview
Problem
Floating-body type wind turbines experience self-excited vibrations due to pitch control, leading to excessive fatigue loads on the generator, which existing technologies fail to detect and mitigate effectively.
Innovation Solution
A monitoring unit is integrated into the wind turbine system to detect abnormal vibrations by analyzing statistical values based on inclination angle and inclination-angular velocity fluctuations, using filters to isolate relevant components and set threshold values adaptable to wind conditions, enabling early detection and prevention of excessive stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If pitch angles are controlled to maintain rotor rotation speed at rated speed, then rotor rotation speed is maintained, but floating body sway is promoted causing self-excited vibration
Solution Approach 1:
The patent implements a monitoring unit that continuously measures the floating body's inclination angle and inclination angular velocity, and feeds this information back to the control unit. The control unit calculates a statistical value representing sway amplitude and compares it against a threshold to detect abnormal vibrations, enabling real-time feedback control to mitigate self-excited vibrations while maintaining rated rotor speed.
2Speed
If pitch angles are increased to maintain rotor speed when floating body moves upwind, then rotor rotation speed is maintained, but thrust force decreases enhancing upwind movement
Solution Approach 1:
The monitoring unit detects changes in the floating body's inclination angle and inclination angular velocity before they lead to excessive sway. By calculating the statistical value and comparing it to the threshold in advance, the system can take preliminary corrective actions through pitch angle adjustment to prevent the thrust force reduction that would otherwise enhance upwind movement and promote further sway.
3Speed
If pitch angles are decreased to maintain rotor speed when floating body moves downwind, then rotor rotation speed is maintained, but thrust force increases enhancing downwind movement
Solution Approach 1:
The control unit continuously monitors the floating body's motion state through the monitoring unit and adjusts pitch angles based on real-time feedback. When downwind movement is detected through changes in inclination angle and angular velocity, the system modulates pitch angles to maintain rotor speed while preventing excessive thrust force increases that would amplify downwind movement and sway amplitude.
4Reliability
If statistical value monitoring is implemented to detect abnormal vibration, then fatigue load risk is reduced, but device complexity increases
Solution Approach 1:
The monitoring unit utilizes the floating body's own motion sensors (inclination angle and inclination angular velocity) to self-diagnose abnormal vibrations. The control unit calculates the statistical value using existing operational data without requiring external monitoring equipment, enabling the system to monitor its own health status and detect fatigue load risks using its existing operational parameters.
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
The system effectively detects abnormal vibrations caused by pitch control, reducing the risk of fatigue damage by alerting operators or automatically stopping the turbine when abnormal sway is detected, thus extending the lifespan of the wind turbine generator.
Implementation Method 1
a monitoring unit for monitoring vibration of the floating body. The monitoring unit is configured to detect abnormal vibration due to execution of the control mode
Data Source
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AI summary
A floating-body type wind turbine power generating apparatus (1) includes a floating body (20), a wind turbine generator (10) erected on the floating body (20), the wind turbine generator (10) including a rotor (13) having a hub (14) and a blade (15) mounted to the hub (14), a control unit (50) capable of executing a control mode in which a pitch angle of the blade (15) is controlled so that a rotation speed of the rotor (13) is maintained at a rated rotation speed, and a monitoring unit (30) for monitoring vibration of the floating body (20). The monitoring unit (30) is configured to detect abnormal vibration due to execution of the control mode by the control unit (50), on the basis of a statistical value over a period of not less than a floating-body sway natural period of the floating body (20), the statistical value being based on a fluctuation amount of a value obtained from a signal representing at least one of an inclination angle or an inclination-angular velocity of the floating body (20). Figure 2