Study On Energy Management Strategy Of 35-Horsepower Dual-motor Power Split Flow Electric Tractor

The traditional fuel tractor has the problem of poor economy and emission,which will pollute the environment.The emergence of electric tractor is one of the effective ways to solve these problems.Dual-motor coupled electric tractors provide sufficient power under complex tractor conditions.In this study,the 35-horsepower dual-motor power split-flow electric tractor is proposed to solve the problem of restricting the endurance capacity and power optimization of the electric tractor to complete the different working conditions of the farmland,with the maximum backup power of the whole machine and the optimal energy efficiency as the goal.The energy management strategy of 35 hp dual-motor power split flow electric tractor is presented.Firstly,the structure of power coupling system of electric tractor with double motor power shunting is analyzed.In Matlab/Simulink,according to the electromagnetic torque characteristics of the motor and the method of querying the efficiency chart of the motor,the model of the main motor and the speed-regulating motor is constructed.The equivalent circuit model of battery Rint and the experimental data of battery charging and discharging are analyzed to complete the construction of the battery model;the driver model is built by using the theory of PID algorithm;the longitudinal dynamics model of the whole machine is established according to the force analysis of tractor driving.Secondly,the energy management strategy of the electric tractor is designed,and the acceleration pedal signal is identified by the adaptive neural network fuzzy control algorithm,and the working mode of the electric tractor is divided based on the instantaneous optimization pattern recognition strategy.Optimization of torque and Speed allocation of Electric Tractor driven by Coupling Speed based on Fuzzy Control Power Distribution Strategy.The off-line simulation of the electric tractor simulation system based on Matlab/Simulink platform shows that the electric tractor can follow the speed demand in time under the rotating field condition,and the energy consumption rate of the electric tractor is 8.2kW·h /mu and 6.7kW·h /mu respectively under the ploughing and rotary tillage conditions.Finally,the hardware of the energy management controller is designed,and the software of the energy management controller is developed by using the rapid control prototype,and the software is compiled and downloaded.Then the controller as the test object is connected with the NI real-time simulator,and the hardware-in-the-loop test platform is built and the corresponding experiments are carried out.From the results of hardware-in-loop experiment,it is shown that the main motor responds quickly to the change of PTO load on the power output shaft,and the PTO speed is stabilized at the target speed of 540r/min all the time;and the tractor speed reaches10km/h when dual motors work at the same time;the battery power dropped the fastest during the tillage,indicating that the energy consumption was the highest at this time.It shows that the energy management strategy of electric tractor designed in this paper is effective and reliable in real-time operation.