Power Flow Simulation in the Product Development Process of Modern Vehicular DC Distribution Systems

Nowadays, automakers face unprecedented requirements to comply and exceed quality standards while attending to consumer expectations. Among the challenges are the insertion of new functions for driving assistance towards highly automated vehicles, electrification and connectivity. Introduction of simulation – driven design in the broad wide disciplines involved within vehicles development yields significant savings in both costs and product release time. This paper introduces an approach to vehicle electrical distribution systems (EDS) simulation adapting the methods used conventionally in transmission and distribution systems to the special features found in the vehicle EDS. To this purpose, a procedure based on a backward/forward sweep (BFS) algorithm for solving power flows in weakly meshed dc traction networks is applied and described. An important part of the work has to do with the information pre-processing from the modular based format used in automotive industry into standard simulation matrices. Constant current load profiles are assumed for the consumers, while the electronic control units (ECU) are considered static power distribution boxes. The main outputs of the proposed methodology are nodal voltages, branch currents and differential voltages at components terminals in the vehicle EDS. The knowledge extracted from the simulation will help the designers during the dimensioning and validation process of modern vehicles EDS and will be a powerful tool to reach the zero-prototypes goal before the start of production.