Propulsion

About: Propulsion is a research topic. Over the lifetime, 24977 publications have been published within this topic receiving 200311 citations.

Motors/generators for traction/propulsion applications: A review

Abstract: The growing interest in electrification has led to a growing interest in hybrid/electrical traction applications. Many hybrid/electrical vehicles have been commercially introduced. Various technologies for the traction motors/generators have been developed. The requirements for motors/generators for hybrid/electrical traction applications are very demanding in terms of power density, efficiency, and cost. This article will provide a comprehensive review of the state of the art highlighting the key global trends and tradeoff of various technologies. The article will also discuss future trends and potential areas of research. The article will cover light-duty vehicles (with more focus), medium- and heavy-duty vehicles, off-highway vehicles (OHVs), locomotives, and ship propulsion. The goal of the article is to serve as a comprehensive reference for engineers working in the traction/propulsion area.

Rare-earth-free propulsion motors for electric vehicles: A technology review

Abstract: Several factors including fossil fuels scarcity, prices volatility, greenhouse gas emissions or current pollution levels in metropolitan areas are forcing the development of greener transportation systems based on more efficient electric and hybrid vehicles. Most of the current hybrid electric vehicles use electric motors containing powerful rare-earth permanent magnets. However, both private companies and estates are aware of possible future shortages, price uncertainty and geographical concentration of some critical rare-earth elements needed to manufacture such magnets. Therefore, there is a growing interest in developing electric motors for vehicular propulsion systems without rare-earth permanent magnets. In this paper this problematic is addressed and the state-of-the-art of the electric motor technologies for vehicular propulsion systems is reviewed, where the features required, design considerations and restrictions are addressed.

History and State of the Art in Commercial Electric Ship Propulsion, Integrated Power Systems, and Future Trends

Abstract: Electric propulsion has emerged as one of the most efficient propulsion arrangements for several vessel types over the last decades. Even though examples can be found in the history at the end of 19th century, and further into the 20th century, the modern use of electric propulsion started in the 1980s along with the development of semiconductor switching devices to be used in high power drives (dc drives and later ac-to-ac drives). This development opened up for full rpm control of propellers and thrusters, and thereby enabling a simplification of the mechanical structure. However, the main reason for using electric propulsion in commercial ship applications is the potential for fuel savings compared to equivalent mechanical alternatives, except for icebreakers where the performance of an electric powered propeller is superior to a combustion engine powered propeller. The fuel saving potential lies within the fact that the applicable vessels have a highly varying operation profile and are seldom run at full power. This favors the power plant principle in which electric power can be produced at any time with optimum running of prime movers, e.g., diesel engines, by turning on and off units depending on the power demand for propulsion and other vessel loads. Icebreakers were among the first vessels to take advantage of this technology later followed by cruise vessel, and the offshore drilling vessels operating with dynamic positioning (DP). The converter technology was rapidly developing and soon the dc drives were replaced with ac drives. In the same period electric propulsion emerged as basic standard for large cruise liners, and DP operated drilling vessels, but also found its way into other segments as shuttle tankers, ferries, and other special vessels. At the same time podded propulsion were introduced, where the electric motor was mounted directly on the propeller shaft in a submerged 360 $^{\circ}$ steerable pod, adding better efficiency, improved maneuvering, and reduced installation space/cost to the benefits of electric propulsion. The future trends are now focusing on further optimization of efficiency by allowing multiple energy sources, independent operation of individual power producers, and energy storage for various applications, such as power back up, peak shaving, or emission free operation (short voyages).