A Simulation Based Analysis of 12V and 48V Microhybrid Systems Across Vehicle Segments and Drive Cycles

The majority of studies in automotive electrification technology focus on the performance of high voltage HEV and EV powertrains. With the introduction of microhybrid systems as a near term technology trend, this work focuses on an analysis of low voltage (<60V) systems across multiple vehicle segments and region-specific regulatory drive cycles. Vehicle simulation results are presented for 12V and 48V vehicle systems equipped with start-stop and regenerative braking, features commonly associated with microhybrid vehicles. Simulation results show that fuel economy benefits from start-stop vary significantly between drive cycles. In contrast, total energy recuperation is similar across all vehicle classes for 12V microhybrid systems. For 48V systems, total recuperated energy increases with vehicle mass while the percent fuel economy benefit is highest for lighter vehicles. The results suggest that a single 12V electrification system may be implemented for a range of segments and that technology adaptation trends will be influenced by region specific regulatory drive cycles.