Performance improvements of auxiliary drives for automotive pump and fan applications

The need to increase electrification in the automotive industry has been well recognized. Overshadowed by their larger counterparts used for the car’s traction is the increasing number of small electric drives used in automotive applications. As a matter of fact, up to 100 of such drives are used within a typical mid-sized car. This includes performance-, safety-, and comfort-related auxiliary drives, of which around 10 % are used as parts of pumping and fan systems. With such “small drives,” i.e., fractional horsepower (FHP) drives at the lower end of the power spectrum, volume, mass, and efficiency have so far only been attributed secondary importance. Yet, the increasing demands on the automotive industry have also resulted in renewed interest not only in the performance parameters of these auxiliary drives, such as energy conversion efficiency, size, and cost, but also in electromagnetic emission, noise, and fault tolerance. This survey article presents selected results on recent achievements in these rather new fields of research and outlines fundamental research questions.