Adaptive Efficiency and Temperature Management for Electric Traction Drives

In drive systems for individual traffic, a tendency towards an increasing electrification of drive components can be observed. To guarantee the continuity of this development for the future in a sustainable manner as well as the jobs associated with, it is necessary to produce electrified vehicles at low cost. Considering the life cycle costs of the overall system, the reliability of every individual component also plays an important role. In this respect, the thermal load on each system component is one major parameter.

Within the scope of a joint research project funded by the German Research Association for Power Transmission Engineering  (FVA), dynamic control methods for application in electric cars are developed and investigated, with the aim to reduce the power consumed by the electric drive system and to increase thermal utilization of the semiconductors used in the power electronic equipment. For this purpose, the degrees of freedom of the elecric drive system, consisting of electrical machine, inverter and DC/DC converter, are used to adapt the switching frequency, the modulation method, the DC link voltage and the rotor flux rate while the electrical machine is running. This control strategy, which is aiming at an optimised operation, is developed with the assistance of simulations, and its potential is investigated. The results are validated by measurements carried out on a demonstrator test bench.