Production cost modeling for permanent magnet synchronous machines for electric vehicles

摘要

A cost model for the estimation of production costs of permanent magnet synchronous machines (PMSM) is presented, whichallows to alter design choices such as wire technology, winding layout, cooling system, materials and more. With the goal to makeresults reproducible by others, the methods are explained in detail and used data and assumptions are given. The developed modelhelps to understand the interaction between the design of PMSM, manufacturing methods and the resulting costs. With it, differentPMSM technologies and materials can be evaluated regarding its influence on the production costs, which is a perquisite to findthe best compromise between performance and costs. Production volume is shown to be the most decisive factor for the resultingproduction costs. Between minimum and maximum assumed volumes, an average cost per unit reduction of 67 could be observed.Furthermore, the results imply that the winding production is responsible for the greatest part of the overall costs, followed bythe rotor assembly (including rare earth magnets). When using the model to compare different wire types, it can be stated that upto a production volume of roughly 150,000 units/year, hairpin wires are more expensive to produce. Above this volume, hairpinwindings will get cheaper than round wire windings due to its higher grade of automation of the production process. Throughthe conducted investigations and the presented results, it is demonstrated that the cost model can serve to evaluate technologieswith regards to costs in the early development stage. This way a more holistic assessment of technologies for PMSM is possible,helping to find the ideal compromises between costs and performance and to increase the attractiveness of sustainable mobility.