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.

https://ietresearch.onlinelibrary.wiley.com/doi/pdf/10.1049/iet-est.2015.0050

Thermal management of electric machines

Review of Thermal Packaging Technologies for Automotive Power Electronics for Traction Purposes

Proton exchange membrane fuel cell (PEMFC) vehicles (PEMFCV) have drawn tremendous attention owing to the advantages of low or zero emissions. Effective integrated thermal management systems (ITMS) considering thermal loops coupling and interaction and with a rational strategy are crucial for the efficient and secure operation of PEMFCV. Therefore, ITMS in PEMFCV are worthy to be reviewed comprehensively. This paper aims to provide the general and current ideas of ITMS design in PEMFCV from part-level to system-level, along with control strategies. The factors that affect the thermal performance of heat-generating components and systems are deeply analysed, and the key findings, challenges, and future work are presented. It is found that liquid cooling is more appropriate for ITMS because of the high specific heat and the convenience of integrating other thermal systems, and that heat pumps tend to be a more suitable choice for air conditioning systems. The future work mainly includes the improvement of cooling and cold start of PEMFC, perfection and verification of waste heat recovery system, exploration of new air conditioning systems, integration of systems, coupling of ITMS and energy management systems, and enhancement of model accuracy. The provided information is useful to guide the system layout and control strategies for ITMS at the early design stage. 

Progress and perspectives of integrated thermal management systems in PEM fuel cell vehicles: A review

A critical review on thermal management technologies for motors in electric cars

https://kar.kent.ac.uk/92656/2/Revised%20Manuscript%E2%80%94%E2%80%94ATE.pdf

Electric motor cooling affects the power capability of electric motors, which has direct impacts on power density and cost In this paper we present a sensitivity study of factors associated with electric motor thermal management specific to electrified vehicle propulsion applications Thermal models of two electric motor configurations were developed and validated against available test data Once confidence was established in the thermal models, a sensitivity analysis was performed over a range of thermal management control factors These factors included heat transfer coefficients, cooling locations, material orthotropic thermal conductivity properties, heat distributions, and interface contact resistances The work helps prioritize future research efforts to improve motor thermal management

Sensitivity analysis of traction drive motor cooling

Electric-drive systems, which include electric machines and power electronics, are a key enabling technology to meet increasing automotive fuel economy standards, improve energy security, address environmental concerns, and support economic development. Enabling cost-effective electric-drive systems requires reductions in inverter power semiconductor area, which increases challenges associated with heat removal. In this paper, we demonstrate an integrated approach to the design of thermal management systems for power semiconductors that matches the passive thermal resistance of the packaging with the active convective cooling performance of the heat exchanger. The heat exchanger concept builds on existing semiconductor thermal management improvements described in literature and patents, which include improved bonded interface materials, direct cooling of the semiconductor packages, and double-sided cooling. The key difference in the described concept is the achievement of high heat transfer performance with less aggressive cooling techniques by optimizing the passive and active heat transfer paths. An extruded aluminum design was selected because of its lower tooling cost, higher performance, and scalability in comparison to cast aluminum. Results demonstrated a 102% heat flux improvement and a package heat density improvement over 30%, which achieved the thermal performance targets.

/pdf/novel-power-electronics-three-dimensional-heat-exchanger-8vinuozof4.pdf

Justin Cousineau

Papers

Sensitivity analysis of traction drive motor cooling

Novel power electronics three-dimensional heat exchanger