Current measurement-based detection of load torque changes in a variable speed VSI induction motor drive to support motor diagnostics

Most spectrum analysis methods used to extract features from the vibration signal measured at the motor frame require the motor to be in the stationary state during the whole measurement. In this paper, the possibility to detect transient states based on the data available in an inverter is studied. The theoretical background is introduced, and practical measurements are carried out. The sensors that exist in the inverter are utilized, and the data is retrieved using ModbusTCP. No modifications to the inverter are required.