Experimental Demonstration of a High-Power Density Electric Generator

Abstract

Electric vehicles (EVs) and hybrid powertrain vehicles are an increasingly common alternative to pure gasoline vehicles. However, most have significantly shorter drivable ranges than combustion engine vehicles, require a long waiting period to recharge, have a low specific power, or are prohibitively expensive and heavy. The goal of this work is to develop and showcase a high-power density generator, which may be used as a component in an EV or hybrid drivetrain. The generator can be used as, for example, a range extender for an EV, or a generator for hybrid powertrains where specific power is important, such as in unmanned aerial vehicles, marine applications, motorcycles, and all terrain vehicles. Moreover, the generator of this work is constructed from commercially available components configured to be easily transportable and remain substantially lightweight. The device discussed in this work comprises a two-stroke single-cylinder gasoline engine and a compact permanent magnet brushless dynamo, assembled as a generator. The advantages of this combination include compactness, simplicity, lower weight, and high specific power. This paper discusses the design and experimental development of such a portable high-power-density power generator. The performance and emissions characteristics of the generator are investigated at varying loads and engine speed. During preliminary experiments, the power generator produced 8.5 kW while having a dry weight of 21 kg. Future design recommendations for the use of alternative or renewable fuels are also explored.