The Useful Life of Inverter-Based Drive Bearings: Methods and Research Directions from Localized Maintenace to Prognosis

In this article, we try to bridge the gap between the knowledge of the effects of bearing currents as they may occur with modern power electronics-based variable-speed drives and the prediction of a bearing's remaining useful life (RUL). We discuss the measurements used and the procedures and methods that have been developed. We identify what we consider to be the necessary next steps and the open questions that exist as well as what we consider to be necessary actions to establish tools and methods for the reliable estimation of the RUL of bearings using measurements of different characteristics and costs.