Slot Wedges with Integrated Grounded Electrodes for Suppression of Inverter-Induced Bearing Currents

Abstract

Reliable operation of electric motors is vital for industrial applications. Yet bearing currents pose significant threats to their efficiency and longevity. Parasitic electrical currents, particularly prevalent in modern machines powered by advanced frequency converters, lead to various detrimental effects including overheating, increased vibration, and premature bearing failure. To address this issue, various countermeasures have been explored, with strategies targeting both the inverter and machine sides. Among these, the Grounded Electrodes approach and Winding Placement approach have proven promising in mitigating bearing currents. However, challenges such as complexity and practical implementation hinder widespread adoption of the technology. In this paper, a novel method integrating grounded electrodes into slot wedges is proposed, aiming to enhance practical applicability while maintaining efficacy. Numerical evaluations demonstrate the effectiveness of this approach compared to other methods, showing its potential to improve the reliability of electric machines by reducing the risk of bearing currents occurrence.