In the past decade, car manufacturers have started electrifying the traction chain of their vehicles. Although these vehicles attract more and more drivers, most of them have a limited range and are prohibitively expensive. Manufacturers must therefore offer high-performance conversion chains (particularly in terms of efficiency) while controlling costs. The power converter is a particularly crucial element of the conversion chains: it supplies the traction motor, and its structure and the way it is controlled can greatly influence the overall efficiency of the drive train. This paper studies two conversion structures that can be used as vehicle power converters, which are modeled and associated with an electric machine. The first is a classical three-phase inverter, and the second is a breakthrough architecture called IBIS (Intelligent Battery Integrated System). This battery integrates the conversion function directly into the battery, which reduces material costs. Two loss phenomena are also studied and modeled (with the help of finite element methods): iron losses in the electrical machine (magnetic losses in the ferromagnetic material used) and copper losses in the conductors (AC and DC losses in the conductors). The impact of the architecture is evaluated on a set of operating points from a road cycle standardized by the WLTP procedure.