Wind Turbine Rotor Balancing by Phase-Angle Mass Placement

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Solution Overview

Problem

Wind turbine rotor imbalances, in terms of both mass distribution and position, lead to increased loads and vibrations, reducing the fatigue life of components and necessitating costly on-site corrections and premature shutdowns due to excessive vibrations, especially under adverse weather conditions.

Innovation Solution

A method and system for wind turbine rotor balancing that identifies angular reference positions, calculates the magnitude and phase of rotor imbalance, and adjusts the mass distribution by placing balancing masses only when necessary, minimizing the amount of mass added and ensuring the phase of imbalance is within a permissible range to reduce loads and vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If balancing masses are added to correct rotor imbalance, then the rotor balance is improved, but the weight of the rotor increases

Engineering Contradiction:
Improverotor balanceVSAvoidrotor weight
Core Design Contradiction:
Stability of the object's compositionVSWeight of moving object

Solution Approach 1:

The patent applies parameter changes by considering not only the magnitude of imbalance but also the angular position of the center of gravity. By calculating both the magnitude and phase angle of the imbalance vector, the method determines the optimal position and amount of balancing mass, thereby minimizing the required correction mass while achieving proper rotor balance.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If the center of gravity position is not aligned with the rotation axis, then the rotor can be manufactured simpler, but increased loads and vibrations occur

Engineering Contradiction:
Improverotor manufacturingVSAvoidloads and vibrations
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent implements preliminary action by performing rotor balancing before the rotor is installed in the wind turbine. The method calculates the imbalance magnitude and phase, determines the required balancing mass and its position, and applies the correction in advance. This prevents excessive loads and vibrations during operation and avoids costly on-site interventions after installation.

Inventive Principle:
Principle #10Preliminary action

3Object-affected harmful factors

If factory balancing is performed to reduce vibrations, then the rotor balance is improved, but the amount of mass needed for balancing increases

Engineering Contradiction:
ImprovevibrationsVSAvoidbalancing mass
Core Design Contradiction:
Object-affected harmful factorsVSWeight of moving object

Solution Approach 1:

The patent minimizes balancing mass by considering the angular position parameter. Instead of simply adding mass to counterbalance the imbalance magnitude, the method calculates the phase angle of the imbalance and positions the balancing mass optimally. This approach reduces the required balancing mass compared to conventional methods while achieving the same vibration reduction effect.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3225841B1Wind turbine rotor balancing method, associated system and wind turbine
Publication Date: 2021.10.20 NORDEX ENERGY SPAIN SAU
  • EP3225841B1 patent drawingFigure 1~2
  • EP3225841B1 patent drawingFigure 3
  • EP3225841B1 patent drawing

AI summary

The present invention relates to a wind turbine rotor balancing method which compensates imbalances between the centres of gravity of the wind turbine blades, in both magnitude and position along said blades, so that the amount of mass needed to carry out this balancing method is minimized, while reducing the loads and vibrations associated with a position of the centre of gravity of the rotor not aligned with the axis of rotation thereof, wherein the invention further relates to the wind turbine rotor balancing system and the wind turbine balanced with the above method.