Traction motors play a critical role in electrified vehicles, including electric, hybrid electric, and plug-in hybrid electric vehicles. With high efficiency and power density, interior permanent magnet (IPM) synchronous machines have been employed in many commercialized electrified powertrains. In this paper, three different IPM rotor design configurations, which have been used in electrified powertrains from Toyota, Nissan, and General Motors, are comparatively investigated. Each topology is redesigned and improved to meet new design requirements based on the same constraints. The designed motors are then compared and comprehensively evaluated for motor performance, torque segregation, demagnetization, mechanical stress, and radial forces. The results suggest that the single V-shaped configuration achieves the best overall performance and is thus recommended as the best candidate.

Electric machines have broadly been used in many industries including the transportation industry. With the evolving trend of electrification in transportation, electric machines with higher power density and higher efficiency are demanded and, thus, more stringent thermal management requirements are needed for electrified vehicle applications. This study comprehensively presents various important aspects of thermal management in electric machines with the main focus on transportation applications. Design considerations, challenges, and methods for enhanced thermal management are discussed. Fundamental thermal properties of common materials are presented and sources of losses in various parts of machines are explained. Furthermore, typical cooling techniques and thermal analysis approaches for electric machines are reviewed in detail. This study will serve as a reference guideline for machine designers, who are interested in thermal management, and for thermal researchers working on electric machines.

The technical maturity and rapidly increasing market share of electrified vehicles have given more importance to the cabin thermal management. Efficient thermal management has a key role to maintain adequate electric operating range, protect components from aging and ensure passenger comfort. This research comprehensively reviews the cabin thermal management systems for electrified vehicles. Various vehicle cabin thermal modeling techniques and the key concepts for cabin thermal comfort have been discussed. Different technical and operational solutions of the cabin thermal management in hot and cold climate conditions are evaluated. The recent developments including heat pumps, thermal system control, passive thermal management, and cabin preconditioning to increase thermal management efficiency are analyzed. The results show that increasing amount of research is focusing on improving the thermal efficiency of the individual electrical components and the vehicle level systems. However, new solutions will be required for reducing the cabin thermal load under hot conditions and improving the heating system operational flexibility and efficiency in cold climates.

Thermal management is becoming ever more important in passenger vehicles in the trend of vehicle electrification. Even though most of the passenger vehicles still have relatively conventional thermal management systems, advanced technologies have been increasingly developed. The internal combustion engine (ICE) have had the central role in thermal management but due to the powertrain hybridization and electrification, the engines are nowadays more efficient, smaller in size, and running less frequently. Especially for plug-in hybrid and electric vehicles, engines are not always used or not even available, and thus there is no excess heat readily available. This paper reviews the present technology for the thermal management of electrified powertrains in passenger vehicles. In this context, thermal management takes into account the cooling and heating systems for the powertrain components, and different methods to develop and improve thermal systems efficiency. The paper investigates the recent technology advances for improving energy efficiency of thermal systems. The research focus is on the hybrid and electric vehicles and especially on the challenges of improving thermal energy efficiency and performance.

This paper proposes the design and development of an external rotor permanent magnet in-wheel motor for an electric bicycle application. The proposed machine utilizes V-shape magnets embedded in the external rotor to achieve enhanced magnetic flux concentration and, hence, high torque and power output. Detailed design principles and performance characteristics of the proposed machine are comprehensively evaluated with finite element analysis (FEA). Various design concerns are further investigated to ensure machine rigidity and operational safety. Finally, this paper validates the design concept with a prototype machine. High torque and high power output are achieved and the experimental results confirm the design simulations with good agreement.

The increase in pollution and carbon dioxide in the transportation sector motivates many countries to establish rules to reduce the emission and carbon footprint. The partial or total electrification of the automotive propulsion system is mandatory to minimize the impact of transportation on the environment. There are multiple possible architectures to electrify the vehicle propulsion system, with different degrees of electrification, and each of the architectures can provide a different balance between energy efficiency, vehicle performance, comfort, drivability, and safety. This article aims to present the definition of the automotive propulsion system electrification, the various degrees of electrification and operation modes, and the possible configurations of an electrified propulsion system by the electric machine position. This article also introduces the definition of the subsystems of the propulsion systems and their components, with an explanation of the subsystem and each of their parts. Based on the state-of-the-art technology development, it intends to present the industry’s common sense and knowledge on automotive propulsion system electrification and proposes a process to follow in the electrified propulsion system architecture selection.