Wind Turbine Control Method for Overspeed Prevention

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Solution Overview

Problem

Wind turbines with variable speed and blade pitch control face challenges in detecting and preventing overspeeds caused by weather conditions, leading to mechanical loads and power generation disruptions during adverse weather.

Innovation Solution

A control method that uses a control parameter indicative of wind turbulence's effect on rotor speed, comparing it to a threshold value to reduce maximum power generation and prevent overspeeds, involving historical data analysis and simulation to define threshold values, and utilizing multiple wind measurement signals to ensure accurate detection and reduction strategies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If shutdown operations are performed when rotational speed or wind values exceed thresholds, then the wind turbine is protected in severe weather conditions, but mechanical loads are increased due to sudden disconnection and fast blade movement, and power generation is prevented during shutdown

Engineering Contradiction:
Improveprotection in severe weatherVSAvoidmechanical loads from sudden disconnection
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The control system performs preliminary actions by gradually reducing power and rotational speed before a complete shutdown is necessary. The method implements a progressive control strategy where power is reduced in stages based on increasing wind speeds and turbulence, allowing the turbine to transition smoothly from normal operation to shutdown rather than making sudden disconnections.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention applies dynamic control by continuously adjusting operational parameters based on real-time wind conditions. The control method uses variable thresholds and adaptive power reduction strategies that respond to changing turbulence intensity and wind speed, enabling the turbine to maintain optimal performance while avoiding mechanical shocks associated with fixed-threshold shutdowns.

Inventive Principle:
Principle #15Dynamics

2Power

If the wind turbine operates in high winds regime with blade pitch angle control, then nominal power is maintained, but overspeeds may occur due to wind turbulence causing shutdowns

Engineering Contradiction:
Improvenominal power productionVSAvoidrotational speed variability
Core Design Contradiction:
PowerVSSpeed

Solution Approach 1:

The control method implements feedback control by continuously monitoring rotational speed, wind speed, and turbulence intensity, then adjusting power output and blade pitch angle in response. The system uses measured deviations from expected rotational speed as feedback to modulate power generation, preventing overspeeds while maintaining nominal power production under varying wind conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The invention changes operational parameters dynamically by adjusting both power output and blade pitch angle based on real-time wind conditions. The control method modifies multiple parameters simultaneously - reducing power when turbulence increases and adjusting pitch angle to control rotational speed - thereby maintaining stable operation across varying wind regimes without triggering shutdowns.

Inventive Principle:
Principle #35Parameter changes

3Loss of information

If turbulence intensity is used to characterize wind conditions, then wind properties are described, but the effect on rotor speed variability is not directly captured

Engineering Contradiction:
Improvewind characterizationVSAvoidrotor speed effect detection
Core Design Contradiction:
Loss of informationVSMeasurement precision

Solution Approach 1:

The control method applies asymmetric control strategies by implementing different response thresholds and adjustment factors for increasing versus decreasing wind conditions. The system recognizes that the same turbulence intensity can have different impacts on rotor speed depending on the direction of change, and applies tailored control actions accordingly - more aggressive power reduction when wind increases suddenly, and more gradual restoration when conditions improve.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP2233736B1Control method of a wind turbine and wind trubine
Publication Date: 2017.08.16 ACCIONA WINDPOWER
  • EP2233736B1 patent drawingFigure 1~3
  • EP2233736B1 patent drawingFigure 4
  • EP2233736B1 patent drawingFigure 5~6

AI summary

This invention is applicable to a wind turbine of variable speed and blade pitch angle control, and its purpose is to detect weather conditions capable of provoking overspeeds in the rotation of the rotor and to prevent them through a reduction in power. This method makes it possible to obtain a control parameter (P), indicative of the fluctuations in the rotational speed of the rotor foreseeable due to wind turbulence, calculated on the basis of a signal (Pw) indicative of the wind power and a signal (TI) indicative of the turbulence intensity of the wind, so as to then compare the control parameter with a threshold value (T), and proceed to reduce the maximum power to be generated by the wind turbine if the control parameter exceeds the threshold value.