On-line fault diagnosis method for motor of machine tool

摘要

The present invention relates to a fault diagnosis method of an electric motor, and more particularly, to an on-line fault diagnosis method of a motor for a machine tool which can accurately diagnose a fault of a diagnosis target motor in operation in the field. The present invention provides on-line fault diagnosis method of a motor for a machine tool, to diagnose the generation of a fault in the motor or the light/heavy/none of the fault, comprising: a) a current signal measuring step (S11) of measuring a current signal of the motor according to a time for which a diagnosis target motor for a machine tool is operated; b) an effective value calculating step (S12) of calculating an effective value of the current signal according to a time by using the current signal of the motor measured in the current signal measuring step (S11); c) a steady state checking step (S13) of checking whether or not there is a steady state with respect to the effective value of the current signal based on the fluctuation width of the effective value of the current signal with a time; and d) a motor status diagnosing step of diagnosing the generation of a fault in the motor or the light/heavy/none of the fault by performing a frequency analysis on the current signal in the steady state when the steady state exists.