Study of wire distribution in a slot of a motor fed by steep fronted pulses for lifetime extension

This paper proposes many technical recommendations in order to improve the lifetime of high reliability machine winding fed by PWM inverters. It bring to the fore to the specific constraints tied to random winding by a computation of winding turn-to-turn maximum voltage stress for any combination of the wire positions in the stator slot. That computation is based on an equivalent circuit of the winding presented in previous publications. The exploitation of the tool leads to several recommendations concerning the winding techniques, the turn-to-turn impregnation and finally the turn-to-ground insulation.