Selection of the Main Parameters for a Traction Electric Motor Based on Vehicle Dynamics Simulation Results

BACKGROUND: This article addresses the rational selection of key parameters for a traction electric motor designed to operate with a single-flow transmission in electric vehicles (EVs) or series hybrids. The analysis accounts for requirements such as achieving maximum speed, climbing gradients (20°), and meeting specified acceleration times (0–100 km/h in 14 seconds). Traditional approaches for internal combustion engine selection typically focus only on maximum speed operation. As an example, calculations are provided for a passenger car with specifications representative of a compact-class vehicle, which is highly suitable for urban environments. AIMS: To develop a methodology for selecting key TEM parameters (rated power, peak power, torque, shaft rotational speed) based on mathematical modeling of EV dynamics in characteristic operating modes: maximum speed, gradient climbing, and uniform acceleration.. MATERIALS AND METHODS: In this study, the MATLAB software package was used to simulate vehicle dynamics. To obtain research results, various parametric variables were analyzed and compared. For example, the influence of different gradients, acceleration times, and maximum speeds on the vehicle's motor power was investigated. Simultaneously, the relationship between the gear ratio and the maximum rotational speed of the electric motor shaft, as well as the correlation between the maximum rotational speed of the electric motor shaft and the vehicle's maximum speed, were examined. RESULTS: 1)Power requirements under specified conditions:19.5 kW (maximum speed),31.97 kW (20° gradient at 20 km/h),57.5 kW (acceleration to 100 km/h in 14 s).2)Selected TEM specifications:Rated power: 22 kW,Peak power: 55 kW (overload coefficient λ = 2.5),Rated torque: 70 Nm.3)Validation: Linear dependencies of vehicle speed on TEM shaft rotational speed confirmed model adequacy. CONCLUSIONS: The article concludes with the advantages, characteristics, and applications of the proposed methodology. Final parameters for the electromechanical transmission, derived through this approach, are presented. The method enables optimized TEM sizing to balance energy efficiency, performance, and cost in urban-focused EVs/hybrids. .