Wind Turbine Converter Control for Torque Surge Mitigation

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Solution Overview

Problem

High torque levels and torque gradients in wind turbine generators controlled using virtual synchronous machine schemes lead to mechanical stress and potential damage, particularly due to sudden changes in power contribution requirements.

Innovation Solution

A method to control the line-side converter in wind turbine generators by determining torque and active power surpluses, using them as input parameters to adjust the active power output and prevent excessive torque levels and gradients, employing a virtual synchronous machine control scheme.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a wind turbine generator operates in full load region with high wind speeds, then power generation capacity is maximized, but excessive torque and torque gradients are generated causing mechanical stress and component fatigue

Engineering Contradiction:

Improvepower generation capacityVSAvoidmechanical stress on components

Core Design Contradiction:

PowerVSStrength

Solution Approach 1:

A damping torque is introduced as an intermediary force to counteract the excessive torque generated by the wind turbine generator. This damping torque acts as a mediator between the excessive driving torque and the mechanical components, reducing the net torque transmitted to the drivetrain and thereby protecting components from excessive stress and fatigue while maintaining full load power generation capability

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The control system dynamically adjusts the damping torque parameter based on real-time operating conditions including wind speed, rotor speed, and torque measurements. By changing the damping torque parameter adaptively, the system optimizes the balance between power generation and mechanical stress reduction, ensuring components operate within safe stress limits while maximizing energy capture

Inventive Principle:

Principle #35Parameter changes

2Reliability

If torque levels are reduced through damping torque, then mechanical stress and component fatigue are minimized, but control complexity increases due to continuous monitoring and adjustment requirements

Engineering Contradiction:

Improvecomponent durabilityVSAvoidcontrol system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The control system implements a feedback mechanism that continuously monitors torque levels, rotor speed, and operating conditions. Based on this feedback, the controller automatically adjusts the damping torque applied to the drivetrain. This closed-loop feedback control ensures reliable component protection while managing complexity through automated regulation rather than manual intervention

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The damping torque control system is designed to self-regulate based on predefined control algorithms and real-time sensor data. The system automatically determines the appropriate damping torque level without requiring external intervention or complex manual adjustments, thereby improving component durability while keeping the control system manageable through self-service operation

Inventive Principle:

Principle #25Self-service

3Stability of the object's composition

If damping torque is applied to reduce torque gradients, then transient torque peaks during wind gusts are suppressed, but response time to counteract torque variations is reduced

Engineering Contradiction:

Improvetorque stabilityVSAvoidresponse speed to torque changes

Core Design Contradiction:

Stability of the object's compositionVSSpeed

Solution Approach 1:

The control system applies preliminary damping torque adjustments in anticipation of torque variations by monitoring predictive parameters such as wind speed trends and rotor acceleration. By taking preliminary action before severe torque gradients occur, the system stabilizes torque levels proactively while maintaining adequate response time to actual torque changes through advance preparation of damping corrections

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP4193458B1Method for reducing high torque levels and torque gradients in wind turbine generators

Publication Date: 2026.04.15 VESTAS WIND SYSTEMS AS

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AI summary

Aspects of the present invention relate to a method (100) for reducing high torque levels and/or high rates of change of torque in a wind turbine generator (10) that comprises a machine-side converter (28) and a line-side converter (30) connected by a DC link (32), and, wherein the line-side converter (30) is operated according to a virtual synchronous machine control scheme. The method (100) comprises: determining (102) a generator torque (Tref); determining (104) a torque surplus (Tsurplus) indicating the amount that the generator torque (Tref) exceeds a torque limit; determining (106) an active power surplus (Psurplus) corresponding to the torque surplus (Tsurplus); controlling (108) the line-side converter (30) according to the virtual synchronous machine control scheme using an input parameter configured to reduce the active power output of the line side converter (30) by the active power surplus (Psurplus).