【作者】 张庆永；

【导师】 常思勤；

【作者基本信息】 南京理工大学 ， 车辆工程， 2009， 博士

【摘要】 本文以串联式液驱混合动力车辆液压系统为研究对象,采用理论研究、试验装置验证和原理样车试验等方法,对液驱混合动力车辆液压系统的建模、设计和液驱混合动力车辆的性能等进行了研究。(1)选择了串联式液驱混合动力车辆液压系统的技术方案,建立了集成车辆负载的串联式液驱混合动力车辆液压系统的数学模型。对液压系统的关键元件如液压蓄能器、双向变量马达等进行了详细分析。提出了液压蓄能器工作过程的变多变指数的新计算方法。(2)采用模糊数学的方法对车辆工况进行判别。选择具有代表性的驱动模式,通过自定义的参数来对这些驱动工况进行描述。应用多层次综合评判,比较实际工况和代表性工况的相关性,对实际工况进行综合评价。(3)对液驱混合车辆的功能要求和液压系统工作过程进行分析,得到了液驱混合动力车辆液压系统的设计要求和设计思想。建立液驱混合动力车辆液压系统的评价准则,采用平均供能功率、最大供能功率、制动能量回收效率和系统能量利用效率等评价指标来指导液驱混合动力车辆液压系统的设计。同时将车辆工况的模糊识别应用到液驱混合动力车辆液压系统的设计中。(4)完成了液压系统转速控制动态特性仿真,对所得到的仿真结果进行了分析,并在自行研制的试验装置上进行了验证性试验。仿真计算的结果与试验结果基本吻合,表明了系统模型和仿真算法的正确性；利用验证后的模型,对液驱混合动力车辆的动力性能进行了研究,对城市循环十五工况下的经济性能进行了仿真；应用基于量化因子和决策因子自修正的模糊PID控制算法进行了十五工况的转速控制仿真,对十五工况下液压系统的评价指标进行了分析；从功率流的观点出发,对液驱混合动力车辆制动能量回收过程进行研究并进行了仿真计算,详细研究了液驱混合动力车辆制动能量回收过程中能量损耗的构成及其相对比例,并对双向变量马达排量、管径、制动初始压力和蓄能器容积等主要设计参数对制动能量回收效率以及车辆制动性能的影响进行了定量分析。(5)研制了“液驱混合动力车辆液压系统试验装置”,在试验室对液驱混合动力车辆液压系统动态性能进行研究。该装置以液驱混合动力车辆中应用的定压网络液压马达控制系统为基础,用调速电机作为原动机带动变量泵工作,由磁粉制动器和惯性飞轮的组合模拟车轮的实际负载并可实现模拟负载的实时控制与调节,采用计算机进行数据采集与控制。完成了不同工况下的试验,对液压系统的动态特性进行了分析。(6)在理论研究和试验验证的基础上,设计、研制了基于定压网络液压马达控制技术的串联式液驱混合动力车辆样车。进行实际样车的设计和改装,制定实际车辆液压系统的布置方案和管路连接方案,进行液压系统和控制系统的调试。基于实际样车系统,开展了一系列试验,分析实际车辆液压系统运行情况,对不同工况下的液驱混合动力车辆液压系统动态特性进行研究。更多还原

【Abstract】 Study on the hydraulic system of series hydraulic hybrid vehicles (SHHV) was presented in this dissertation. Based on the theoretic research, the test bench of the hydraulic system for SHHV and the prototype vehicle were developed. Computer simulation and experiments of the hydraulic system for SHHV were performed.(1) Technical scheme of the hydraulic system for SHHV was chosen, and the mathematical models of hydraulic system integrated with vehicle load were established. The key components of hydraulic system such as the hydraulic accumulator and bidirectional variable-displacement motor were analyzed detailedly. Some key parameters influencing dynamic performance of hydraulic system were analyzed. The calculation method of variable polytropic index was proposed.(2) Fuzzy algorithm was applied to identify vehicle operating condition. Four representative driving patterns were selected as vehicle duty cycles. Some self-defined parameters were chosen to characterize the driving patterns. Multilevel comprehensive assessment was applied to evaluate the real duty cycle.(3) The function and working process of SHHV were analyzed. Evaluating indexes, such as average power-supplying rate, maximum power-supplying rate, braking energy regenerative efficiency and utilizing efficiency of hydraulic ststem, were established to direct the design of hydraulic system for SHHV. The fuzzy assessment of vehicle driving cycles was applied to the design of the hydraulic system for SHHV.(4) Simulation was performed on the dynamic characteristic of speed controlling system of the hydraulic system and simulation results were analyzed. Verification experiment was perfomed on the self-developed test bench. The simulation results accorded with the experimental data well. The accuracy of systematic models and simulation algorithm was testified. By using the verified mathematical models, power performance and fuel economy of SHHV were studied; fuzzy PID algorithm based on the auto-tuning of scaling factor and decision-making factor was applied to perform the simulation of fifteen-mode driving cycle, evaluating indexes of hydraulic system on 15-mode driving cycle were analyzed; Mathematical models based on the power flow of braking energy recovery for hydraulic hybrid vehicles were established and simulation was implemented. Evaluation indexes of braking energy regenerative system were defined. Constitute of energy loss and corresponding proportion were studied detailedly during the process of braking energy recovery. Quantitative analysis was made to study the influence of bidirectional motor displacement, pipe diameter, initial braking pressure and volume of accumulator on energy regenerative efficiency and braking performance of the vehicle.(5) The test bench of hydraulic system for SHHV was developed in the lab to study its dynamic characteristic. The test bench based on hydraulic motor controlling system in the constant pressure net used transducer motor to drive pump working, wheel load was simulated and real-time controlled through the combination of magnetic particle brake and fly wheel, and data collecting and controlling scheme were implemented by a computer. Different duty-cylces of hydraulic system were tested on the test bench and its dynamic characteristics was analyzed.(6) The prototype vehicle of SHHV based on hydrostatic transmission was built up. The technical and disposal scheme were developed. The hydraulic system and controlling system tests were carried out. Some experiments based on the prototype vehicle and control system were made.更多还原