Design and analysis of a power transmission system for 55 kW electric tractor using agricultural workload data

In this study, an e-powertrain system for 55 kW electric tractors was designed and analyzed using agricultural workload data. The electric tractor power transmission system structure was analyzed, and three types were selected: the single-motor, the dual-motor, and the dual-motor including a planetary gear set (PGS). Load measurement and analysis during agricultural operations were performed to determine motor specifications and compare the characteristics of these three structures. Type I is a single-motor type and exhibits the highest torque and output of 62.8 kW at 199.5 Nm. Since the engine is replaced with a motor, a conventional transmission system with a clutch is adopted. Types II and III are dual-motor types and are classified by the use of a PGS. The PTO motor specifications are the same, namely, approximately 55.3 kW at 176.0 Nm. Notably, when a PGS is employed, the driving motor specifications can be significantly reduced from 58.4 kW at 185.3 Nm to 11.8 kW at 37.7 Nm. Hence, this is advantageous for saving space and optimizing the layout, which are key design elements of electric tractors. This study could facilitate future optimization and development.