A kind of new simulation of electric field distribution in a PWM inverter-fed motor stator winding subjected to steep-fronted surge voltages

摘要

Before, the methode of simulating the high-frequency contents of inverter-fed traction motor and the winding inter-turn voltage distribution has been the equivalent circuit model. The main simulating tool has been MATLAB. But now another method may be better than this one. Based on electromagnetic field theories, this paper researches the effect of steep-fronted voltage wave-shapes infringing on a pulse-width-modulated (PWM) inverter fed induction motor. Its work is finished by using ANSYS simulation software. It main offers a new simulation method for overvoltage pulse exerting in the motor stator windings. And the method predicts the voltage stress distribution among the coils of the stator winding. Since the new method utilized the 3 D transient field analyzing module and 3D static field module of ANSYS software and coupled them correctly. It is a breakthrough comparing with the traditional circuitry simulation method. The coupling progress is that the transient magnetic field caused by over-voltage pulse is computed firstly. Then at this time that the over-voltage is reached its peak, the static electric field caused by the results from the former transient magnetic field is computed secondly. So the progress is called indirect coupling. At last the new method can offer the whole electric stress distribution in detail in the motor stator windings. It is more conformable to research or design the stator insulation structure for a PWM inverter motor.