Wind Turbine Pitch Control via Operational Parameter Estimation

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Solution Overview

Problem

Existing wind turbine control systems are inadequate in responding quickly and reliably to sudden changes in wind load conditions, leading to potential extreme loads and damage due to their slow reaction times and inaccuracy in detecting wind direction and speed variations.

Innovation Solution

A control method that estimates operational parameters such as rotor power, torque, and thrust coefficients to rapidly adjust control strategies, including de-rating or shutting down the turbine, to mitigate extreme loads by modifying pitch references and power settings based on real-time wind load conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the pitch controller is designed to react to fast changing wind conditions, then the response speed improves, but the system complexity and cost increase

Engineering Contradiction:
Improveresponse speedVSAvoidcontroller complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The control method performs preliminary estimation of operational parameters (power coefficient, torque coefficient, thrust coefficient) continuously during normal operation, so that when extreme wind conditions occur, the controller already has pre-calculated data ready for immediate action. This eliminates the need for complex real-time calculations during emergency situations, achieving fast response without proportionally increasing controller complexity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces complex mechanical sensing systems with computational estimation methods. Instead of using additional physical sensors and complex mechanical detection systems to directly measure wind conditions, the controller estimates operational parameters through mathematical calculations based on available data, achieving fast detection through computational rather than mechanical means.

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

2Device complexity

If the controller uses generator speed-based pitch control, then the system simplicity is maintained, but the control accuracy deteriorates under gusty wind conditions

Engineering Contradiction:
Improvecontrol system simplicityVSAvoidwind detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent introduces operational parameters (power coefficient, torque coefficient, thrust coefficient) as intermediary variables between the generator speed measurement and the pitch control decision. These intermediaries provide more accurate information about the actual wind conditions and turbine performance, enabling better control accuracy while maintaining the simplicity of using existing generator speed data.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If the turbine maintains stationary operating points, then the power production is optimized, but the ability to handle dynamic wind conditions deteriorates

Engineering Contradiction:
Improvepower productionVSAvoiddynamic response capability
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The control method dynamically adjusts the pitch reference based on real-time estimation of operational parameters and comparison with pre-stored extreme condition data. Instead of maintaining fixed stationary operating points, the system continuously adapts its control strategy by selecting from pre-calculated pitch references that are optimal for different wind conditions, achieving both dynamic responsiveness and optimized power production.

Inventive Principle:
Principle #15Dynamics

4Device complexity

If the controller reacts slowly to wind changes, then the system simplicity is maintained, but the extreme load protection deteriorates

Engineering Contradiction:
Improvecontrol system simplicityVSAvoidextreme load protection
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The controller performs preliminary estimation of operational parameters and continuously compares them with pre-stored reference values for extreme wind conditions. This preliminary preparation ensures that when extreme conditions are detected, the controller can immediately initiate protective actions without complex real-time analysis, maintaining system simplicity while significantly improving extreme load protection reliability.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2486272B1Control method for a wind turbine
Publication Date: 2016.03.23 VESTAS WIND SYSTEMS AS
  • EP2486272B1 patent drawingFigure 1
  • EP2486272B1 patent drawingFigure 2
  • EP2486272B1 patent drawingFigure 3

AI summary

The invention relates to a method of controlling a wind turbine having a rotor with pitchable wind turbine blades and a generator for producing power, where a control signal for a controllable parameter of the wind turbine is determined, and an operational parameter representing a loading on the wind turbine exerted by the wind is estimated at time intervals. From this is determined a variation parameter reflecting the variation of the operational parameter over time. The wind turbine is then controlled according to the control signal only if the variation parameter is below an alert threshold, and otherwise according to a modified control strategy.