Wind Turbine Blade State Estimation for Tower Strike Prevention

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Solution Overview

Problem

Existing methods to prevent rotor blade collisions with the tower in wind turbines either reduce efficiency or require costly hardware and lack reliable data for collision prevention.

Innovation Solution

Employing a state estimator that combines measurements from multiple units, including inertial measurement units and GPS receivers, to accurately and continuously estimate the position of rotor blades and towers, using algorithms like Kalman filters for robust data fusion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If rotor blades are stiffened, coned, and/or prebend is introduced to prevent tower strike, then collision risk is reduced, but power production capability and efficiency are reduced

Engineering Contradiction:
Improvecollision riskVSAvoidpower production capability
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent replaces mechanical structural modifications (stiffening, coning, prebend) with a sensor-based monitoring and control system. Strain gauges, accelerometers, and other sensors detect blade deflection in real-time, and the control system adjusts pitch or yaw to prevent tower strike, thereby maintaining full blade structural efficiency while preventing collisions.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements a feedback control system that continuously monitors blade deflection through strain measurements and accelerometric data, compares the measured deflection against safe operating thresholds, and automatically adjusts turbine operation (pitch control, yaw control, or shutdown) to prevent tower strike. This closed-loop feedback enables collision prevention without permanent structural modifications that would reduce power production.

Inventive Principle:
Principle #23Feedback

2Productivity

If active control approaches are used to prevent collision by changing operating state based on measured data, then efficiency is improved compared to passive structural measures, but high-cost hardware and reliable data requirements increase

Engineering Contradiction:
ImproveefficiencyVSAvoidhardware cost and data requirements
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent makes existing turbine components serve dual functions: strain gauges and accelerometers originally intended for general structural monitoring are also used for tower strike prevention. The same sensors provide data for both routine structural health monitoring and real-time collision risk assessment, eliminating the need for separate dedicated hardware and reducing overall system complexity and cost.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The control system uses the turbine's own existing measurement infrastructure (strain gauges, accelerometers, pitch actuators, yaw system) to prevent tower strike. Rather than requiring external expensive hardware, the system leverages the turbine's self-diagnostic capabilities and existing control mechanisms to autonomously prevent collisions, thereby reducing hardware costs while maintaining efficiency.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4569220B1Preventing blade tower strike of a wind turbine
Publication Date: 2026.04.01 SIEMENS GAMESA RENEWABLE ENERGY AS
  • EP4569220B1 patent drawingFigure 1
  • EP4569220B1 patent drawingFigure 2~3
  • EP4569220B1 patent drawingFigure 4

AI summary

Preventing blade tower strike of a wind turbine A method of estimating a position of at least a part of a ro- tor blade of a rotor of a wind turbine during operation of the wind turbine is provided. The part of the rotor blade is a first part. The rotor blade (103) is deflected due to a de- flection motion of the rotor blade towards a tower (104) of the wind turbine (101) and the position is indicative of said deflection. The method (400) comprises measuring a first pa- rameter by a first measuring unit (107), wherein the measured first parameter is indicative of an absolute and/or a rela- tive position of at least a second part of the rotor blade (103) or of a further rotor blade (102) of the rotor. The method (400) further comprises measuring one or more second parameters by one or more second measuring units (108), wherein at least one of the one or more measured second pa- rameters is indicative of an absolute and/or a relative posi- tion of at least a third part of the rotor blade (103) or of the further rotor blade (102) of the rotor. The method (400) further comprises estimating the position of the at least first part of the rotor blade (103), wherein the estimating comprises employing a state estimator (210) that estimates a state of the rotor blade (103) based on at least the measured first parameter and the one or more measured second parame- ters and deriving the position from the estimated state of the rotor blade (103).