# Design and Verification of a Modular Reconfigurable Test Platform for Electric Tractors
## 1 Introduction
Next, a test bench featuring a series-parallel hybrid electric powertrain architecture, where the engine distributes power to the generator and the PTO shaft through the power-split device, was established in [16] to study the dynamic performance of this architecture through the traction experiment. Using BETs with multi-motor drive powertrains, [PERSON] et al. [17] designed a powertrain for a 78 kW all-wheel-drive BET prototype to analyze the reduction gear ratio under actual agricultural working and driving conditions. [PERSON] et al. [18] established a four-wheel independent driving electric tractor test bench to research the torque distribution of BETs under the working conditions of the traction operation. Recently, BETs with dual-motor drive powertrains have become increasingly attractive to manufacturers and researchers. In 2017, agricultural equipment manufacturer John Deere released the first fully public BET prototype called sustainable energy supply for agricultural machinery. This prototype was equipped with two electric motors, one of which was used to operate the drivetrain, while the other was used for the PTO and auxiliary systems. If required, both motors can work together to supply full power. In other words, the powertrain architecture of this prototype can be a dual-motor independent drive or a dual-motor coupling drive [19; 20]. [PERSON] et al. [21; 22] designed a tractor test bench with a dual-motor coupling powertrain to verify the optimality of the matched parameters obtained from the particle swarm optimization algorithm based on a mixed penalty function. Additionally, based on this test bench, two experiments featuring a constant load and the traction performance were performed to verify the effectiveness of the control strategy and the power distribution ratio [23]. To date, due to complex factors, for example, heavy and complicated farming load conditions, different farming operations, and various powertrain architectures, researchers and manufacturers generally build corresponding test platforms or prototypes to study various powertrain architectures for electric tractors. However, it is time-consuming and costly to establish test benches or prototypes for each powertrain architecture while also considering different farming operations and environments. Therefore, it is necessary to design tools and methodologies for developing a comprehensive test bench that can realize different agricultural works as much as possible. In this paper, a reconfigurable test bench for an electric tractor was developed according to the analysis of powertrain topologies. Then, to verify the feasibility of the reconfigurable test platform, we chose two of the powertrain architectures of an electric tractor to implement the rotary tillage experiment. Specifically, a reconfigurable test platform can satisfy the research into different powertrain architectures to the greatest degree possible in addition to the advantages of strong expandability, high-efficiency, and time and cost savings. Second, a series hybrid electric powertrain and a pure electric powertrain were selected to verify the feasibility of the reconfigurable concept for the test bench by carrying out the rotary tillage operation. This paper is organized as follows: In Section 2, different powertrain topologies of ETs are analyzed. Section 3 introduces in detail a test platform with reconfigurable components and a control system. Next, a series hybrid electric powertrain and a pure electric powertrain were built and tested based on the framework of the platform. The main parameters of the rotary tillage experiment are described in Section 4. Section 5 shows the experimental results under the rotary tillage operation to validate the feasibility of the proposed reconfigurable method and verify the accuracy of the established test bench. Finally, the conclusions are given in Section 5.