Wind Turbine Rotor Unbalance Control via Adjustable Biasing

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Solution Overview

Problem

Wind turbines with hinged blades face rotor unbalance issues due to varying operating parameters, design features, and environmental factors, leading to uneven loads and potential damage, which existing methods fail to address efficiently and reliably.

Innovation Solution

A method for operating wind turbines with hinged blades that involves an adjustable biasing mechanism to balance pivot angles by applying adjustable forces, monitoring rotor unbalance, and adjusting these forces to minimize imbalance, regardless of its origin, using a combination of mechanical and hydraulic systems to control pivot angles and mitigate uneven loads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If wind turbine blades are connected via hinges to allow pivot angle variation, then the rotor diameter can be varied to control power output and loads, but rotor unbalance occurs due to varying operating parameters and design features leading to uneven loads

Engineering Contradiction:
Improvepivot angle variation capabilityVSAvoidrotor balance stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies counterbalancing forces through the biasing mechanism to compensate for the unbalance caused by hinge-connected blades. The biasing force acts as a counterweight mechanism that offsets the uneven loads generated when blades pivot to different angles, thereby maintaining rotor balance stability while preserving adaptability.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The patent dynamically adjusts the biasing force parameter to compensate for rotor unbalance. By changing the magnitude of the biasing force applied to hinged blades, the system maintains optimal balance conditions across varying operating parameters and pivot angles, resolving the contradiction between adaptability and reliability.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If biasing force is applied to hinged blades to control pivot angle, then rotor balance can be maintained, but additional mechanical components and control complexity are introduced

Engineering Contradiction:
Improverotor balance controlVSAvoidbiasing mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The biasing mechanism is designed to serve multiple functions: it applies biasing force to control pivot angles, compensates for rotor unbalance, and adapts to varying operating conditions. By consolidating these functions into a single mechanism, the patent reduces overall system complexity while maintaining reliable rotor balance control.

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

Solution Approach 2:

The control system automatically monitors rotor balance conditions and adjusts the biasing force without requiring external intervention. This self-regulating capability simplifies operation and reduces the complexity of manual control systems, as the mechanism serves itself by detecting and correcting imbalances autonomously.

Inventive Principle:
Principle #25Self-service

3Reliability

If rotor unbalance is monitored and biasing force is adjusted in real-time, then uneven loads can be minimized and damage prevented, but energy consumption and system complexity increase

Engineering Contradiction:
Improvedamage prevention capabilityVSAvoidenergy consumption for monitoring and adjustment
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements a feedback control system that monitors rotor balance conditions and adjusts the biasing force accordingly. By using feedback from sensors that detect pivot angles and load conditions, the system efficiently minimizes energy consumption by only activating adjustments when unbalance is detected, rather than continuous operation, thus preventing damage while managing energy use.

Inventive Principle:
Principle #23Feedback

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

Effectively reduces rotor unbalance by adjusting biasing forces, thereby minimizing uneven loads and preventing damage, while adapting to changing wind conditions and blade characteristics, ensuring efficient energy extraction and prolonged turbine operation.

Implementation Method 1

an adjustable biasing mechanism arranged to apply an adjustable biasing force to each wind turbine blade which biases the wind turbine blade towards a position defining minimum pivot angle or towards a position defining maximum pivot angle

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

the pivot angle of each wind turbine blade is a result of the balancing between at least the adjustable biasing force and a wind load force acting on the respective wind turbine blade

Methodology Applied
Scientific EffectAerodynamic Force: Aerofoil

Data Source

PatentEP4055268B1A method for handling rotor unbalance of a wind turbine with hinged wind turbine blades
Publication Date: 2023.02.22 VESTAS WIND SYSTEMS AS
  • EP4055268B1 patent drawingFigure 1
  • EP4055268B1 patent drawingFigure 2
  • EP4055268B1 patent drawingFigure 3

AI summary

A method for operating a wind turbine (1) with hinged wind turbine blades (5) is disclosed. The wind turbine (1) comprises an adjustable biasing mechanism (8, 10, 11) arranged to apply an adjustable biasing force to each wind turbine blade (5) which biases the wind turbine blade (5) towards a position defining a minimum pivot angle or towards a position defining maximum pivot angle. A biasing force is selected for each wind turbine blade (5) and the selected biasing force is applied to the respective wind turbine blades (5). The wind turbine (1) is operated while monitoring rotor unbalance of the wind turbine (1). In the case that the rotor unbalance exceeds a first threshold value at least one of the wind turbine blades (5) is selected, and the biasing force applied to the selected wind turbine blade(s) (5) is adjusted.