Computer simulated extracted parameters of induction motor for unequal variation in state of degradation of insulation in all three-phases

Abstract

The variation in state of degradation of stator winding insulation in induction motor results in the state of unbalance in three-phase stator current at fundamental frequency. The computer simulation model to determine this state of unbalance is subsequently developed and presented in the previous research paper. On the basis of park's current transformation model the unbalanced stator current data in three-phase machine variable form is first transformed into two-phase park's current vector component form. The park's current vector components are then presented in a graphical form over a dq-plane and some specific mathematical parameters are extracted. In this investigation, the simulated electrical variables in equivalent two-phase (`dq') model form and associated extracted mathematical parameters of induction motor under test are presented for a particular case. The performance assessment of extracted features for a particular case of an unequal variation in the state of degradation of insulation in all three-phases is presented. The particular conditions like maximum variation from healthy to intermediate to worst-case state in one particular phase with minimum variation in healthy state of insulation in the `leading-phase,' and undisturbed healthy state of insulation present in the `lagging-phase,' respectively, are considered to represent an unequal state of degradation of stator insulation present in all three-phases.