Autonomous load shutdown mechanism as a voltage stabilization method in automotive power nets

The power demand in 14 V automotive power buses has steadily increased in recent years. Due to the high peak power of electrified chassis control systems, significant voltage drops can occur within the power net. These voltage drops can lead to malfunctions of ECUs (Electronic Control Units). This paper describes the influence of an autonomous load shutdown mechanism on voltage stability in automotive power buses. The mechanism is applied to heating systems, which feature a combined peak power demand of over 1 kW in modern luxury class vehicles. A temporary shutdown of these heating systems for a few seconds is unnoticeable for the costumer due to large time constants of these systems. The influence of the mechanism on the voltage stability is investigated within a physical power net simulation. It is shown, that the mechanism allows the negligence of power-hungry heating systems in the design process of the power bus regarding peak power scenarios.