Scalable thermal management architecture for electric motor with different power classes

Authors

H. Zhang, G. Rösel, G. Eser, L. Leopold, A. Burkhardt, A. Usai, D. Stojkovic - Vitesco Technologies

Summary

Thermal management of battery-electric vehicles is an essential factor to meet the performance requirements and to increase efficiency, which means range increase, especially in cold and warm ambient conditions. The losses of the electric drives de-pend on the type of electric motor, the different performance requirements, and operating points. Depending on the amount or location of the waste heat generated by the losses, different cooling mechanisms and cooling media are required.

Water has the best thermal properties, but due to the (worse) electrical properties com-pared to di-electric coolants such as e. g. oil, it cannot be used for cooling mechanism with direct contact to the electrically active parts of the electric motor. Different cooling concepts with water-glycol and oil are compared with each other based on real electric machine measurements.

Based on these measurements, simulation models are methodically compared, which enable the development of a scalable cooling building kit. In this way, the most effective and cost-optimal cooling system can always be selected for each application.

The article also takes a closer look at the various chains of action of the cooling types. The various requirements for cooling and heating depending on the electric machine performance classes require a scalable architecture in the form of a flexible modular system for thermal management.

The article shows a scalable thermal management system derived from the chains of action, examples of the design of the thermal components under consideration of efficiency, costs, and ease of integration for different applications.