Optimization and Evaluation of 12V/48V Architectures based on EDS Simulation and real Drive Cycles 2019-01-0482

Both the rising number of electrical systems and the electrical part of the powertrain is considerably increasing the electrical power requirements of vehicles. As a consequence, multiple voltage supply levels have been introduced. However, even if only the 12V/48V configuration is considered, as in this paper, the number of possible electrical distribution system (EDS) architectures is strongly enlarged. Additional degrees of freedom are the allocation of the loads to the voltage levels, the dimensioning of new components, and the control strategy. Hence, the optimization of such architectures must be based on simulation, which allows the evaluation of a multitude of variants and test scenarios within an acceptable time frame. While strict cost, weight, and quality constraints must be upheld, the stability of the voltage supply is a major focus because a significant part of future electrical systems is highly safety-critical. In this paper, quantitative quality criteria for the evaluation of the voltage stability are applied which enable a systematic assessment of the performance of an EDS. The presented approach is based on a modular simulation environment which allows the configuration and dimensioning of various EDS architectures and the use of heterogenous component models. Furthermore, a particular emphasis is placed on the definition of test scenarios, where drive-dependent loads can be activated by stored real drive-cycle data, while the other electrical devices are controlled via a predefined Gantt chart. Thus, realistic test conditions can be simulated and evaluated using the quality criteria mentioned above. The results enable comparative investigations into the impact of the configuration, the operating strategy, and the dimensioning of the 12V/48V components. Thus, the precondition for a systematic optimization is established. The paper presents the implemented simulation environment, the stability criteria, the applied test scenarios, results for a set of EDS architectures, and a comparison and conclusion.