Performance Evaluation and Thermal Analysis of Various Electric Drives for Automotive Electric Propulsion

<div>Electric vehicles (EVs) represent a significant stride toward environmental sustainability, offering a multitude of benefits such as the reduction of greenhouse gas emissions and air pollution. Moreover, EVs play a pivotal role in enhancing energy efficiency and mitigating reliance on fossil fuels, which has propelled their global sales to unprecedented heights over the past decade. Therefore, choosing the right electric drive becomes crucially important. The main objective of this article is to compare various conventional and non-conventional electric drives for electric propulsion in terms of electromechanical energy conversion ratio and the thermal response under continuous [at 12 A/mm<sup>2</sup> and 6000 rpm] and peak [at 25 A/mm<sup>2</sup> and 4000 rpm] operating conditions. The comparative analysis encompasses torque density, power density, torque pulsation, weight, peak and running efficiencies of motor, inverter and traction drive, electromechanical efficiency, and active material cost. This study considered an array of electric traction motor types and their accompanying power converters, including the interior permanent magnet synchronous machine, induction machine, PM-assist synchronous reluctance machine, synchronous reluctance machine, switched reluctance machine, double-stator switched reluctance machine, and double-stator PM synchronous machine. To ensure fairness, all machines share identical outer stator diameters, stack lengths, and current densities. Drive efficiency was assessed using uniform inverters via Ansys Simplorer, while Ansys Fluent was used to conduct consistent thermal analysis to evaluate temperature and cooling effects across all seven machines. Additionally, AVL Cruise M software was utilized to compare the performance of these electric drives under the Worldwide Harmonized Light-Duty Vehicles Test Cycle (WLTC) to simulate the urban, suburban, rural, and highway driving conditions using the Nissan Leaf as the reference electric vehicle.</div>