Bar Winding for the Low-Voltage Motorization of an Electric Tractor

This paper presents the design of a solid bar winding for permanent magnet synchronous motor dedicated to the electric drive of a full electric tractor. The choice of a 75 Vdc low-voltage power distribution requires resorting to a solid bar winding with 1 bar per slot (single turn). This type of motor operates at high frequencies (up to 1600 Hz). Hence, the solid conductors dissipate additional copper losses (higher AC resistance). An analysis of these additional copper losses was carried out to accurately assess the effective AC resistance of the winding and, hence, the efficiency of the electric motor. The tractor prototype and the characteristics of its electric motor were presented here. A full scale prototype of the electric tractor was manufactured and tested on real conditions in order to validate the design.