Application of the VDA standard for the comparison and losses reduction of high efficiency car alternators

The reduction of the CO₂ emission is a challenge for the future. Transportations are one of most important generator of CO₂ and its reduction is directly linked to the reduction of the consumption of vehicles. At the same time vehicles, for comfort and security systems, require more and more electric energy. The alternator efficiency has become of prime importance. Nevertheless, classic characterization of electric machines (maximum efficiency) is not sufficient for car alternators. We introduce the notion of the German VDA standard (verband der automobilindustrie) which allows the comparison of different alternators and evaluate the relative share of the different losses. A model is proposed and used for the determination of the VDA efficiency of a classic commercial car alternator. The relative share of the different losses is discussed and means of reduction are suggested.