A Two-Stroke Range Extender Engine For Heavy Duty BEV applications

Licentiate thesis, 2020

A back-up range extender (REX) is proposed to support battery electric vehicles (BEV) for heavy duty applications. A single cylinder crank case scavenged two-stroke SI-internal combustion engine (ICE) with a turbocharger system is considered powerful and small enough to be installed directly on the existing electric machine in the electric powertrain. The two-stroke engine needs a specially designed turbocharger system assisted by an afterburner system to fulfill the scavenging and exhaust emission requirements. This thesis has investigated and developed such a charging system functionality and demonstrated it on a 125cc engine single cylinder engine. This shows that a 125cc single cylinder two- stroke engine was able to obtain 50 kW or 400 kW/L swept volume indicating that an upscaled version of this engine to 425cc will be able to produce the desired rated power of 150 kW.