A method for the sensorless determination of the vibration level in inverter-driven induction motors

This paper presents a sensorless vibration monitoring method for inverter-driven induction motors. Extensive work has been focused on condition monitoring systems which detect the existence of specific fault-induced harmonics in the current spectrum. Initial investigations into the relationship between current harmonics and their causal vibration harmonics has proven that useful vibration information can be gained in a sensorless fashion by evaluating the current spectrum. The effect of inverter voltage harmonics on the method´s ability to detect an increase in vibration is tested and shown in experimental results