a new 48 V power system in personal vehicles opens up for new possibilities. By
using a low-voltage electric machine with power up to 15 kW, a mild hybrid
electric powertrain can be achieved with components that are smaller and
cheaper than other large full hybrids. The potential in reduction of both fuel
consumption and greenhouse gas emissions is expected to reach 10 % for certain
drive cycles with this topology.
help of a 48 V advanced battery (e.g. li-ion) and a DC/DC converter, many large
electric loads can move from the old 12 V system to the new 48 V bus, enabling
higher system efficiency and thus requiring less fossil fuel to perform the
same job. New, larger electrical loads can also be supported. The 48 V electric
machine can perform load shifting, some brake regeneration and torque boost,
enhancing the vehicle performance.
electromagnetical and thermal design of the 48 V electric machine is the core
of this research project. Vehicle models are used to evaluate different
powertrain topologies in drive cycles such as NEDC and WLTC.
project is funded by Vinnova FFI in cooperation between Chalmers Electric Power
Engineering and Volvo Car Group.