Mild hybrid electric vehicle 48V (MHEV)

In the past, the 48V vehicle electrical system has focused primarily on P0 (Belt-driven integrated Starter Generator, BiSG) and P1 (Crankshaft-mounted integrated Starter Generator, CiSG) configurations in the powertrain of Mild Hybrid Electric Vehicles (MHEV). The motivation for this was the cost advantage, especially the P0 configuration, compared to Battery Electric Vehicles (BEV) or Plug-in Hybrid Electric Vehicles (PHEV), the lower development effort, and the immediate CO2 reduction potential for the vehicle fleet.

Today, we observe a trend to Driveline-mounted P2 - P5 configurations which are positioned after the clutch on the input shaft of the transmission (P2), on the output shaft of the transmission (P3), on the rear axle (P4), or in wheel drive (P5). The benefit of these configurations is higher electrical efficiency compared to P0/ P1 and the capability of recuperating electrical energy with the engine off during coasting. Along with the introduction of Driveline-mounted P2 – P5 configurations, auxiliary applications enter the 48V electric system combined with a 48V Power Distribution (either as the separate box or integrated into the Battery Management, like a Fuse Box).

The main target of the auxiliary 48V applications has been further CO2 reduction, but at the same time, some are used for additional comfort functions, increased drive dynamics, and scalable Four Wheel Drive without CO2 increase.