Design And Optimization Of Drive System For Gardening Electric Tractor

The scale of facilities and horticulture in China has increased year by year.According to official statistics,the current horticultural area of facilities has ranked first in the world.Garden tractors have become an indispensable power machine for mechanization and modernization of modern orchards or tea gardens.Considering that the production of modern tea gardens and orchards is labor intensive and the standardization of operations is high.Therefore,for the horticulture,orchard use,long battery life,high efficiency and environmental protection,the research and analysis of pure electric tractor drive system design that can meet the conditions of ploughing,rotary tillage and light load field transportation has certain theoretical significance and practical value.This paper designs a gardening electric tractor drive system scheme by analyzing the electric vehicle drive structure scheme.The analysis determined the main components of the electric tractor drive system including the drive motor and the type of power battery.Combined with the characteristics of gardening electric tractors,the evaluation index of the dynamics and economy of the vehicle driving system is proposed.The main component parameters of the drive system are designed.The working principle and torque ripple generation mechanism of the brushless DC motor used in electric tractors are studied.The mathematical model of the motor is established.The motor simulation model based on current prediction control is built by using simulink.The double closed loop PI control is compared and based on simulation.The motor performance of the current prediction control shows that the torque ripple of the brushless DC motor based on the current prediction control is significantly smaller.Using Cruise to establish a vehicle simulation model of electric tractor,and simulate the power and economy of the electric tractor by setting corresponding calculation tasks.The results show that the continuous working time under the theoretical working conditions of each gear exceeds 4h,and the traction,climbing degree and speed are all.The range meets the design requirements of the entire vehicle.In order to further improve the driving performance of the whole vehicle,the multi-island genetic algorithm based on Isight multidisciplinary optimization software and Cruise is used to optimize the electric tractor transmission ratio with economy as the main optimization target.The simulation results show that the optimized transmission ratio makes the overall vehicle economy significantly improved.