Storage‐to‐wheels efficiency in a latest plug‐in electric vehicle

Abstract

AbstractThe chemical, electrical, and mechanical power flow of a Chevrolet Spark plug‐in electric vehicle covering the cycles of the United States Environmental Protection Agency (US EPA), Vehicle Testing Regulations, namely the UDDS, Hwy and US06 cycles, is here analyzed. Experimental time series of instantaneous battery voltage and current are coupled to a simple model for energy conversion mechanical‐to‐electrical, and electrical‐to‐mechanical, and vice‐versa, and aerodynamic and rolling losses from Newton's equation model. A detailed CAE model is used to confirm the chassis dynamometer results complemented by the use of Newton's model. Computational time series of chemical, electric and mechanical power and energy are provided. Small advances are undergoing in motor/generator technology, where electric‐to‐mechanical efficiencies may approach 95%, while efficiencies mechanical‐to‐electric may exceed 90%. UDDS, Hwy and US06 efficiencies electric‐to‐wheels and wheels‐to‐electric are ηe−m = 0.794, 0.963, and 0.977, or ηm−e = 0.761, 0.893, and 0.902, respectively. Chemical‐to‐electric or electric‐to‐chemical efficiency ηc−e/e−c is about 0.984. These efficiencies are shared by the different products available on the market, with the weight of the vehicle and aerodynamic and rolling drags ultimately determining the energy efficiency of a specific vehicle.