Wind Turbine Torque Control for Transient-Event Torsional Vibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wind turbines experience undesirable torsional vibrations during transient grid events, which can lead to decoupling of the rotor from the generator and damage to drivetrain components due to mismatched torque and inertia, necessitating improved control systems to manage these vibrations.
Innovation Solution
A control system that includes a controller to detect transient grid events, generate a torque command to establish a default damping level, determine oscillation parameters, and adjust the torque command to achieve an increased damping level to mitigate torsional vibrations, using existing measurements and estimation methods to enhance drivetrain damping without additional hardware.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the wind turbine remains connected to the grid during transient grid events, then the wind turbine can maintain power production and meet grid code requirements, but torsional vibrations in the drivetrain increase due to torque-inertia mismatch
Solution Approach 1:
The controller dynamically adjusts generator torque parameters in response to detected grid faults. By modifying the torque command based on real-time grid voltage measurements and oscillation parameter detection, the system changes operational parameters to reduce torsional vibrations while maintaining connection to the grid.
Solution Approach 2:
The system implements a feedback control mechanism where the controller continuously monitors grid voltage and drivetrain oscillations. Based on this feedback, the controller adjusts the generator torque command to suppress torsional vibrations, creating a closed-loop control system that adapts to changing grid conditions.
2Productivity
If the generator torque is rapidly increased after voltage recovery, then the wind turbine can quickly return to pre-fault power production, but torsional vibrations and mechanical stress on the drivetrain increase
Solution Approach 1:
The controller prepares for voltage recovery by continuously monitoring grid conditions and pre-adjusting the generator torque command. When voltage recovery is detected, the system has already positioned itself to smoothly increase torque, avoiding sudden changes that would cause mechanical stress.
Solution Approach 2:
The system transitions from static torque control to dynamic torque modulation. The generator torque command is continuously adjusted based on real-time detection of oscillation parameters and grid voltage, allowing smooth transitions between operating states while suppressing torsional vibrations.
3Object-affected harmful factors
If additional damping mechanisms are added to the drivetrain, then torsional vibrations can be reduced, but the device complexity and cost increase
Solution Approach 1:
The patent replaces mechanical damping devices with an electrical control solution. Instead of adding physical dampers or springs to the drivetrain, the system uses a controller to adjust generator torque, substituting mechanical damping with electrical control to reduce torsional vibrations.
Solution Approach 2:
The existing generator and controller system serves the dual purpose of power production and vibration suppression. The generator torque control mechanism, already present for normal operation, is utilized to provide damping effects during transient events, eliminating the need for separate damping hardware.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A system and method are provided for controlling a wind turbine. Accordingly, a controller of the wind turbine detects a transient grid event and generates a torque command via a drive-train-damper control module. The torque command is configured to establish a default damping level of a torsional vibration resulting from the transient grid event. The controller also determines at least one oscillation parameter relating to the torsional vibration and determines a target generator torque level based thereon. The target generator torque level corresponds to an increased level of damping the torsional vibration relative to the default damping level.