Modeling and simulation of inter-turn voltage distribution in the stator windings of the pulling motor

A.C. pulling motors controlled by pulsed width modulated (PWM) adjustable speed drives are widely applied in the express locomotive, which leads to premature insulation failure of pulling motors. The pulling motor inter-turn insulation breakdown has been one of the major causes of premature failure. This paper is focused on the modeling and simulation of the traveling wave phenomenon in the pulling motor. A method of estimating the high-frequency distributed-circuit parameters of the motor using finite-element analysis is described. A distributed high frequency equivalent circuit is proposed based on distributed resistance, inductance and capacitance. Transient responses of A.C. pulling motor winding for steep fronted pulse are simulated. Through simulation, the effect of the PWM wave front on the voltage distribution is studied. The result presents theoretical base for the insulation configure design of the pulling motor.