Inverter-Induced Bearing Currents: Analysis for Journal Bearings

This paper investigates the electrical behavior of journal bearings under varying operational conditions and the associated damage caused by the presence of bearing currents. The study focuses on the impact of the motor operating conditions on the lubricating film characteristics, such as its thickness, breakdown voltage, capacitance calculation and the transition between ohmic and capacitive behaviors. A methodology for evaluating damage potential is introduced, linking the current density with temperature rise to assess failure risks. Finite element method simulations validate the proposed models and highlight the significance of local current density in failure mechanisms.