Identification and Elimination of Instabilities During Simulation of Highly Stiff Vehicle Electrical Power System Models

Abstract

In vehicle electrical power system simulations, reliablemodels are required, especially for critical use cases suchas inrush currents, short circuits, and load dumpscenarios. These switching scenarios involve rapid changesin resistance and result in stiff models due to the fastdynamics. Instabilities are observed immediately afterswitching, highlighting significant numerical challenges.In this study, we investigate the origins of theseinaccuracies and propose robust solutions through improvedelectrical models and advanced numerical integrationtechniques with optimized error tolerance settings. Thesuggested decoupling approach employs physical and signalfiltering techniques to replace the variable resistor usedto simulate the fuse switching process. The nominal valuestrategy involves establishing an appropriate baselinevalue. The methods discussed yield stable and accuratesimulations when implemented with appropriately adaptedmodel-specific parameterizations.