Design and commissioning of a low voltage 25 kw PMSM traction drive

Electric vehicles require traction machines with a high efficiency, a high power density and a low weight. Not to forget are aspects like a fail-safe motor operation, a safe maintenance and handling and an easy and cost-effective industrial production. Based on these requirements, a 25 kW PMSM was developed as decentralized scalable drive unit for traction applications. In contrast to conventional high voltage designs, the machine has a concentrated winding with only one turn per coil. Thus, the motor voltage is located in an extra-low voltage range, which reduces the effort and volume for winding insulation. Machines with this winding design can benefit from higher slot fill ratios, a simplified winding assembly and an improved recyclability. The present paper deals with the design and commissioning of this low voltage PMSM traction drive. In addition to motor dimensioning, construction process and practical realization, the challenges of winding configuration are considered. The paper is completed by first results of the machine measuring on an adapted test bench.