Influence Analysis on the Bearings’ Impedance Behavior of Inverter-Fed Motor Drives

The present paper reveals many crucial influences on the bearings’ behavior under electrical high-frequency excitation and helps to understand the phenomena of electric damage in bearings. Such bearing damages are often seen in inverterfed drives. The use of fast-switching power inverters with SiC or GaN semiconductor technologies amplifies and increases the likelihood of such damage. This study describes an influence analysis on the impedance behavior of bearings deployed in inverter-fed drives. In the author’s previous publication, a novel approach for an experimental setup to determine the electric impedance of bearings for traction applications is presented. Based on this test bench, the results of the influence on the investigated parameters such as variations in speed, radial and axial loads, or different types of oil and material of the bearings’ retainer are shown in the present paper.