Yaw Actuator Torque Estimation Using Bolt Strain Calibration

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Solution Overview

Problem

Existing technologies face challenges in accurately estimating the torque of the shafts of yaw actuators in wind turbines, which is crucial for avoiding overload and ensuring efficient operation.

Innovation Solution

A torque estimation system comprising a yaw actuator, bolts with torque meters, a load portion simulating wind force, and a torque estimation device that uses strain sensors to measure bolt strain and generate pre-operation and correspondence information to estimate torque during operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If torque meters are installed on bolts to measure torque before operation, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvetorque measurement precisionVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by performing torque calibration before the wind turbine enters operation. Torque meters are installed on the bolts and calibrated against a reference torque meter during a pre-operation phase when the turbine can be stationary or in controlled conditions. This preliminary calibration establishes accurate correspondence information between bolt strain and actual torque, ensuring measurement precision is achieved before the complex operational phase begins.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If strain sensors are used to measure bolt strain during operation, then measurement capability is improved, but reliability decreases due to inability to estimate torque accurately

Engineering Contradiction:
Improvestrain measurement capabilityVSAvoidtorque estimation reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent implements feedback by using strain sensors on the bolts to continuously measure bolt strain during operation, then feeding this information back to the torque estimation device. The device references the pre-established correspondence information (calibration data) to convert the measured strain into torque estimates. This closed-loop feedback mechanism maintains reliability by continuously comparing actual strain measurements against the calibrated relationship, enabling accurate torque estimation throughout the turbine's operational life.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If a load portion is used to simulate wind force torque before operation, then calibration accuracy is improved, but ease of manufacture worsens

Engineering Contradiction:
Improvecalibration accuracyVSAvoidassembly complexity
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent introduces an intermediary load portion that simulates wind force torque during the calibration phase. This load portion acts as a mediator between the torque meters on the bolts and the reference torque meter, creating a controllable test environment. The load portion can be a temporary mechanical device or software-simulated load that applies known torque values to the drive shaft, enabling accurate calibration without requiring actual wind conditions or complex manufacturing modifications to the turbine structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

The system effectively estimates the torque of the shafts of yaw actuators, enabling real-time monitoring and prevention of overload, thus enhancing the operational efficiency and reliability of wind turbines.

Implementation Method 1

a stress detection element mounted inside the sensor bolt is adapted to detect a length variation of the sensor bolt

Methodology Applied
Scientific EffectStrain: Deformation

Data Source

PatentEP4083588B1Torque estimation system and torque estimation method
Publication Date: 2025.05.14 NABTESCO CORP
  • EP4083588B1 patent drawingFigure 1
  • EP4083588B1 patent drawingFigure 2
  • EP4083588B1 patent drawingFigure 3~7

AI summary

A torque estimation device (8) includes: a current value obtaining unit (7) for obtaining a current value of a drive unit (30) of an actuator (3) included in a wind turbine (101); a storage unit (81) storing correspondence information representing correspondence between a torque occurring in a drive shaft (33) of the drive unit (30) and the current value; and an estimation unit (83) for estimating the torque occurring in the drive shaft (33) based on the current value obtained by the current value obtaining unit (7) and the correspondence information.