Numerical simulation of three phase asynchronous motor to diagnose precisely the stator unbalanced voltage anomaly

In the present paper, series of simulation tests of voltage unbalance, have been performed on triphase induction motor to study this unhealthy condition. First, the stator currents data pattern is used as a preliminary diagnosis. Secondly the extended Park’s vector approach (EPVA) is also used. An elliptic pattern and a 2nd harmonic component are obtained by these two methods respectively. These signatures in other researches are often considered as direct and accurate indicators of a stator winding fault. This similarity leads to uncertainty in the detection of the fault, which makes imperative the use of complementary technique. The focus on the 2nd harmonic of the supply frequency (2.fs) in the torque spectrum (THA technique) has shown its effectiveness as good indicator of voltage unbalances. Therefore, to distinguish between these faults, the THA is considered as the ideal tool for this purpose.Keywords: induction motors, stator voltage unbalance, fault diagnostics, stator currents pattern, EPVA, TH