Optimal Control of a Hybrid Battery/Supercapacitor Storage for Neighborhood Electric Vehicles

Abstract

Abstract Neighborhood Electric Vehicles (NEVs) are an important class of electric vehicles for short range and low speed applications. They are often smaller than highway electric vehicles and cheaper to buy due to their limited features. Most NEVs are powered using lead acid battery packs which are more affordable than other battery technologies. The lead acid batteries used in NEVs offer limited range and limited service life and have to be replaced approximately every three years. Although the performance and range expectations for NEVs are lower than for highway electric vehicles, improving efficient use of the stored charge can save energy and extend the life of the battery pack. An optimally controlled supercapacitor battery hybrid is proposed in this paper to minimize the effects of peak current demands on the battery during an NEV driving cycle. The hybrid storage system shows the ability to reduce the peak current drawn from the battery, which is an important factor in determining battery useable capacity per single charge and the length of battery life. This improvement will lead to lower operating costs for NEVs that will result from significantly lower energy losses and longer battery life.