A High-Frequency Multi-band Coil for Online Bearing Health Monitoring

Induction motors controlled by variable-frequency drives (VFD) tends to experience pre-mature bearing failures due to unwanted bearing currents. Hence, continuous monitoring of high-frequency (HF) bearing currents is necessary so that the correlation between the bearing currents and the bearing health can be better established for better bearing design. This paper proposes a low-cost, wideband and non-intrusive sensing coil to monitor the bearing current.