The state of degradation of stator groundwall insulation in induction motor results in the state of unbalance in three-phase stator current at fundamental frequency. In this investigation, the computer simulation model to determine this state of unbalance is developed. On the basis of park’s transformation model the unbalanced stator current data in three-phase machine variable (‘abc’) form is transformed into equivalent two-phase (‘dq’) model form. The park’s current vector components are then presented in a graphical dq-data pattern form and certain mathematical parameters are deduced. The computer simulation model is designed to extract simulated electrical variables and mathematical parameters of induction motor under test. The practical assumption of stator winding of induction motor being star (*) connected with isolated neutral is considered. The extracted features of induction motor for particular case of variation in the state of degradation of stator groundwall insulation occurring in respective phases is presented. The performance evaluation of extracted features for the variation in the state of degradation of insulation in any two-phases with an intermediate state of degradation present in the remaining phase is presented. On the basis of performance evaluation, it is possible to determine the appropriate selection of specific input parameter for optimal design of suitable artificial neural network classifier to distinguish the probable states of degradation of insulation.

Computer simulation insulation degradation induction motor park’s current transformation stator groundwall insulation