水田作业工况下混合动力拖拉机驱动系统能量消耗规律的研究

The hybrid electric drivetrain has the advantage of reducing energy consumption and emissions, is one of the development direction of the tractor drivetrain technology. At present, the research on the energy consumption mechanism and principle of the hybrid electric drivetrain system is obviously scarce, especially the basic research about hybrid electric tractor in paddy working condition is rarely reported, which has been a theoretical issues need to be addressed urgently for the hybrid electric tractor. This project direct at paddy working condition in southern China, combine the soil-bin experiment and field experiment, research the energy consumption principle of tractor drivetrain system, and establish an energy consumption model and load fluctuation model in paddy working condition. Then, analyze the energy transmission route of the hybrid electric drivetrain system, research the energy consumption principle and efficiency characteristics of the pure mechanical drivetrain, pure electric drivetrain and hybrid electric drivetrain system in different working conditions, establish theoretical models and MAP figures of the engine fuel consumption in pure mechanical drivetrain, the electric energy consumption in pure electric drive, the equivalent energy consumption in hybrid electric drivetrain, the propulsive efficiency and the total transmission efficiency, finally, reveal the best matching principle of the engine fuel consumption, the electric energy consumption and equivalent energy consumption with propulsive efficiency and total transmission efficiency. On the basis of that，reveal the matching principle between the paddy working condition and three drivetrain system. Finally, provide a theoretical basis for the design of the drivetrain system, the selection of drive mode and optimal control strategy of the hybrid electric tractor.

混合动力驱动有降低能耗和减少排放的优点，是拖拉机驱动技术的发展方向之一。目前有关混合动力驱动系统能耗机理和规律的研究明显缺乏，特别是与混合动力拖拉机水田作业工况相关的基础研究鲜有报道，是混合动力拖拉机发展迫切需要解决的理论问题。本项目针对南方水田作业工况，以土槽试验和田间试验相结合的方法，研究拖拉机驱动系统能耗问题，建立水田作业工况下的能耗模型和负载波动模型；分析混合动力驱动系统能量传递路线，研究纯机械驱动、纯电力驱动和混合动力驱动系统在不同工况下的能量消耗规律和效率特性，建立纯机械驱动时发动机燃油消耗量、纯电力驱动时电能消耗量、混合动力驱动时等效能耗以及牵引效率和总传动效率的理论模型和MAP图，揭示发动机燃油消耗量、电能消耗量和等效能耗与牵引效率和总传动效率的配比规律。在此基础上，揭示水田作业工况与三种驱动系统的匹配规律，为混合动力拖拉机驱动系统设计、驱动方式选择和控制策略提供理论依据。

按照国家自然基金项目合同书（51505232），本项目针对南方水田作业工况，搜集土壤样本，采用烘干法和机械水分测试仪测试法，对比研究了土壤含水率准确性测试。主要采用土槽试验的方法，研究了不同含水率和不同作业速度下拖拉机拖挂农机具工作时的负载变化规律，建立了负载模型。基本恢复了并联式混合动力拖拉机试验台，对其测控系统中加载系统进行了控制研究，基本能够实现农田作业负载下的试验研究。. 以拖拉机混合动力驱动系统为研究对象，分析了纯机械驱动、纯电力驱动和混合动力驱动系统能量传递路线，构建了混合动力拖拉机驱动系统中柴油发动机、动力电池、电动机、动力耦合装置、变速器和后桥传动系等的子能耗模型；基于发动机万有特性曲线，结合负载模型，通过加载试验，研究了纯机械驱动系统在不同负载、不同发动机转速和不同变速比下的能量消耗规律和效率特性，建立了发动机燃油消耗量、牵引效率和总传动效率的理论模型和MAP图，找到了发动机燃油消耗量、牵引效率和总传动效率的最佳配比规律；基于蓄电池放电特性和电动机效率特性，结合负载模型，通过加载试验，研究了电力驱动系统在不同负载、不同电动机转速、不同蓄电池电压和不同变速比下的能量消耗规律和效率特性，建立了电能消耗量、牵引效率和总传动效率的理论模型和MAP图，找出了电能消耗量、牵引效率和总传动效率的最佳配比规律。. 结合发动机、蓄电池、电动机、动力耦合装置、变速器和后桥传动系模型，构建了机电耦合系统的理论模型和等效能耗模型，依据负载模型，通过加载试验，研究了混合动力驱动系统在不同负载、不同发动机转速、不同电动机转速、不同蓄电池电压和不同变速比下的能量消耗规律和效率特性，建立了等效能耗、牵引效率和总传动效率理论模型和MAP图，找出了等效能耗、牵引效率和总传动效率的最佳配比规律。在此基础上，研究了水田负载模型与三种不同驱动方式的配比规律。基本完成合同预期目标，总投入资金为14.3021万元，执行了总经费的71.51%。