Wind Turbine Drivetrain Calibration Through Reversed Dual-End Tests
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for calibrating and measuring the efficiency of wind turbine drive trains are limited to torques below 1.1 MNm, failing to accurately capture the mechanical torque on the main shaft, and do not account for parasitic loads present in real-world conditions, leading to inaccurate efficiency measurements.
Innovation Solution
A method involving two tests on a drive train with ends driven by electric motors, where one end is driven in a first test and the other in a second test, with torques measured at both ends and efficiencies determined using predefined assumptions, allowing for direct torque and angular position sensing, and optionally combining electrical power measurements to enhance accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If state-of-the-art calibration systems are used, then calibration is possible up to 1.1 MNm torque, but accurate measurement of mechanical torque on the main shaft (several MNm) is not possible
Solution Approach 1:
The patent inverts the conventional test approach by driving the drive train from the generator end (second end) instead of the drive end (first end). This allows torque to be measured at the generator shaft where lower torques occur, enabling indirect determination of main shaft torque through efficiency calculations. The inversion enables measurement of high torques (several MNm) by measuring lower torques at the opposite end of the drive train.
Solution Approach 2:
The patent introduces efficiency as an intermediary parameter to bridge the gap between measurable quantities and desired measurements. By measuring torque and speed at both ends of the drive train and calculating efficiency, the system can determine main shaft torque indirectly. The efficiency calculation serves as a mediator that connects the measurable generator shaft torque to the unmeasurable main shaft torque.
2Measurement precision
If back-to-back tests with two gearboxes are used, then torque measurement is possible at high torques, but parasitic loads are not applied or difficult to apply evenly
Solution Approach 1:
The patent extracts the parasitic load application from the complex back-to-back gearbox setup and applies it directly to a single drive train. By using the actual wind turbine drive train components (main shaft, gearbox, generator) in a single integrated system rather than two separate gearboxes, the parasitic loads can be applied more naturally and evenly to the mechanical transmission element being tested.
Solution Approach 2:
The patent creates a simplified copy of the operational conditions by driving the drive train from the generator end and applying parasitic loads at the drive end. This copying approach replicates the essential test requirements (torque measurement, parasitic load application) without requiring the complex dual-gearbox back-to-back configuration, thereby reducing setup complexity while maintaining measurement validity.
3Measurement precision
If direct torque measurement at the main shaft is attempted, then accurate torque data would be obtained, but measurement systems must handle several MNm torques which exceeds current calibration capabilities
Solution Approach 1:
Instead of attempting to measure high torque directly at the main shaft, the patent inverts the measurement approach by measuring low torque at the generator shaft and using efficiency calculations to determine the high main shaft torque. This inversion transforms an intractable measurement problem (measuring several MNm) into a solvable problem (measuring lower torques at the generator shaft with existing calibration systems).
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
This approach significantly improves the accuracy of efficiency and torque measurement by reducing measurement uncertainties and expanding the measurable torque range, enabling precise calibration and understanding of wind turbine performance under various loads.
Implementation Method 1
the first and second drive units can also at least partially operate in generator mode
Data Source
Figure 1~2
Figure 3~5
Figure 6~7
AI summary
The invention relates to a method for determining an efficiency of a drive train (1), in particular of a drive train (1) or of a part of a drive train of a wind energy installation (4, 7, 11), wherein the drive train (1) has a first end (1a) with a first shaft section (11) driveable by means of a first drive device (6) and a second end (1b) with a second shaft section (27) driveable by means of a second drive device (7), between which ends a mechanical transmission element, in particular a transmission, is arranged, wherein, in a first test, the first end of the drive train (1) is driven and a variable dependent on the torque acting on the first shaft section at the first end (1a) of the drive train (1) and a variable dependent on the torque acting on the second shaft section at the second end (1b) of the drive train (1) are recorded, and wherein, in a second test, the second end (1b) of the drive train (1) is driven and the variable dependent on the torque acting on the second shaft section at the second end (1b) of the drive train (1) and a variable dependent on the torque acting on the first shaft section at the first end (1a) of the drive train (1) are recorded and an efficiency is determined from the powers determined in the first test and in the second test and/or from the variables dependent on the torques taking into account at least one assumption predetermined on the basis of experiments or experience or analysis.