Posters
Come meet the poster presenters to ask them questions and discuss their work
We would like to invite you to come and see the posters at our upcoming conference. The posters will showcase a diverse range of research topics, and will give delegates an opportunity to engage with the authors and learn more about their work. Whether you are a seasoned researcher or simply curious about the latest developments in your field, we believe that the posters will offer something of interest to everyone. So please join us at the conference and take advantage of this opportunity to learn and engage with your peers in industry and the academic community.
PO437: Experimental quantification of parasitic currents in the HSS bearings of a wind turbine gearbox
Maximilian Zweiffel, Team Lead - Testing, Chair for Wind Power Drives - RWTH Aachen University
Abstract
The competitiveness of wind turbines (WT) is significantly impacted by failures that lead to downtime, particularly those associated with drivetrain components. High-speed shaft (HSS) gearbox bearings often fail before reaching their calculated fatigue life due to unaccounted electrical currents within the bearings. [1,2] These currents arise from common mode (CM) voltages induced by power converters, which connect variable-speed WT drives to the grid. [3] The use of pulse width modulation (PWM) in power converters results in high switching frequencies and steep voltage transitions, creating CM voltages between the generator rotor and housing. CM voltages and currents are transmitted through the HSS and its bearings. Within the bearings, the lubricant film between rollers and raceways acts as an electrical capacitor. When voltage exceeds the breakdown threshold, electrical discharge can damage bearing surfaces, leading to material evaporation, local melting, and surface features like "grey frosting" and "fluting," ultimately causing increased vibrations and bearing damage.[4,5] While previous research has measured HSS voltages entering gearboxes, the currents within gearbox bearings have not yet been quantified. [6] This study aims to develop a method for experimentally quantifying these electrical currents in rolling bearings of HSS in WT gearboxes while also examining different drivetrain topologies and generator concepts. The measured currents will be evaluated against existing limits for bearing currents to enhance WT reliability and reduce downtime through improved designs.
No recording available for this poster.
