Wind Turbine Rotor Imbalance Detection from Stop Position Analysis
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Solution Overview
Problem
Existing methods for detecting rotor imbalance in wind turbines are costly, require external experts, and suffer from measurement inaccuracies due to disturbances such as blade misalignment and generator torque, necessitating a more efficient and accurate method using existing sensors.
Innovation Solution
A method for detecting rotor imbalance in wind turbines using existing sensors by positioning rotor blades in a test flag position, and recording stop positions, and determining imbalance angle positions, and calculating the torque, and determining the amount of imbalance, and calculating the amount of imbalance, without affecting the operation of the wind turbine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If vibration sensors are temporarily installed to detect rotor imbalance, then measurement accuracy is improved, but operational disruption and costs increase
Solution Approach 1:
The wind turbine uses its own existing operational sensors (rotor position sensor, blade angle sensors) to perform self-diagnosis of rotor imbalance. The control system automatically executes the detection method by analyzing data already collected during normal operation, eliminating the need for external measurement equipment and service interventions.
Solution Approach 2:
The patent replaces physical vibration measurement equipment with a computational analysis method that uses electrical sensor data (rotor position and blade angle sensors). Instead of mechanically attaching vibration sensors to the rotor, the system substitutes this with evaluating operational parameters from existing electronic sensing systems.
2Productivity
If existing vibration sensors are used to detect rotor imbalance, then operational continuity is maintained, but measurement accuracy is insufficient
Solution Approach 1:
The patent changes the parameters being measured from general vibration characteristics to specific operational parameters (rotor position, blade angle) that are directly related to imbalance conditions. By analyzing these specific parameters and their relationships during operation, the system achieves accurate imbalance detection without sacrificing operational continuity.
Solution Approach 2:
The control system continuously monitors rotor position and blade angle data, comparing actual measurements against expected values for balanced operation. This feedback mechanism enables real-time detection of imbalance conditions while the turbine remains operational, allowing for continuous productivity with maintained measurement accuracy.
3Reliability
If rotor blades are manufactured with high precision to minimize imbalance, then initial balance is improved, but manufacturing costs increase
Solution Approach 1:
The patent implements preliminary detection of rotor imbalance during the commissioning phase or early operation, identifying which specific blades have excessive mass. This allows for targeted corrective actions (adding or removing mass from specific blades) rather than requiring all blades to be manufactured with extremely high precision, thereby reducing overall manufacturing costs while ensuring operational reliability.
4Ease of repair
If rotor blades are swapped or repaired, then maintenance is performed, but mass imbalance is likely to occur
Solution Approach 1:
The patent replaces complex mechanical balancing procedures with a simple sensor-based detection method. After blade swapping or repair, the control system automatically detects any resulting imbalance using existing sensors, eliminating the need for specialized mechanical balancing equipment and expert service personnel.
Solution Approach 2:
The wind turbine performs self-verification of rotor balance after maintenance activities. The control system monitors operational parameters and automatically identifies imbalance conditions that may have arisen from blade replacement or repair work, enabling the system to self-diagnose problems without external intervention.
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
Enables accurate detection of rotor imbalance without additional equipment, reducing costs and operational impact, allowing for comprehensive knowledge of imbalance conditions across multiple turbines, and facilitating early detection of changes in rotor blades.
Implementation Method 1
a test flag position similar to a flag position... In other words, when the wind turbine and its rotor are aligned with the wind, each rotor blade is in its 'flag' position with its leading edge pointing forward, i.e., towards the wind.
Implementation Method 2
A stop position is then determined at which the rotor either comes to a standstill during the test operation or around which it swings.
Data Source
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AI summary
The invention relates to a method for detecting a mass imbalance of a rotor comprising several rotor blades of a wind turbine, wherein the rotor blades are adjustable in their blade angle and a rotational position of the rotor can be detected as the rotor position, comprising the steps of: operating the wind turbine in a test operation in which the rotor blades are placed in a test flag position similar to a flag position, which deviates from the flag position by no more than a test angle and the wind turbine does not generate power, determining at least one stop position in which the rotor remains stationary in the test operation or about which it oscillates, and determining an imbalance angle position from the at least one stop position.