Electrical Torque Boosting of Down-Sized ICE Vehicles

An effective approach for improving fuel economy and reducing emissions is to employ a down-sized, turbocharged internal combustion engine (ICE). However, turbocharged engines exhibit a relatively low torque capability at low engine speeds. To overcome this problem, an electrical torque boost may be applied whilst accelerating and changing gear, and to facilitate energy recovery during regenerative braking. The paper describes the operational requirements of such a torque boost system, which employs a supercapacitor energy storage buffer, outlines the design and sizing of the electrical machine, and presents test results from a demonstrator system.