Simplified Sizing and Performance Models for Four-Stroke Spark-Ignition Engines for use in Electric Vehicle Range Extenders

The energy storage limitations that currently hinder the marketability of fully-electric vehicles could be overcome with on-board range extenders that consume conventional fuels to generate additional electrical power when needed. This paper presents two simplified tools intended to streamline the initial design of range extender engines.;The first is a simple physics-based model capable of accurately identifying the peak range extender output requirements for highway-capable electric vehicles. The use of this model is demonstrated for three common vehicle types.;The second is a flexible array-based modeling approach capable of performing in-depth simulations of steady-state engine operation. This approach is used to construct a detailed spark-ignition engine model, and this model is used to evaluate the effect of general engine configuration attributes on operation in a range extender. Finally, the design decisions made during the development of existing range extenders are studied, and compared against the results from the engine model.