Modeling and experimental set-up of an automotive electrical network for transient studies

With the increasing number of electronics loads dedicated to both security (ABS, ESP ...), comfort (air conditioning) and entertainment (DVD) in vehicles, it has become critical to study the interactions between them. The transient phases due to on/off switching of electric loads can generate variation of the DC voltage that can influence loads behavior. It has then become important to develop a complete model of the embedded electric network to study loads interactions. First this goes through developing accurate models to help the designers in the sizing of the on-board power system as soon as the first steps of the new vehicle life. In this paper we present (i) the modeling of several components of a 14V automotive network (alternator and loads), and (ii) the experimental network that was set-up to validate the models. Finally, simulation results and measurements are compared and analyzed for transient events (load steps).