无节流损失阀控动力单元的机理与应用研究

发布时间：2018-03-02 02:19

本文关键词： 阀控动力单元无节流损失节能高速开关阀位置控制力控制　出处：《上海交通大学》2012年硕士论文　论文类型：学位论文

【摘要】：液压系统与机械、电力传动系统相比,具有功率密度大、便于实现无级调速和过载保护等优点,被广泛用于工业控制中。但是传统液压系统中存在大量的节流损失和溢流损失,导致系统效率只有30%左右。节能已经成为当今液压技术应用与发展不可忽视的问题之一。本论文正是从减小节流损失和溢流损失的角度出发,提出了无节流损失阀控动力单元的新概念,研究了其实现机理,建立了仿真模型,并对基于无节流损失阀控动力单元的位置、力控制系统进行了控制性能及节能性分析。本论文所开展的主要研究工作有: 首先,总结了当今液压系统中常用的节能技术,从传统液压系统产生能量损失的原因出发,分析了无节流损失阀控动力单元的实现原理;利用二位三通高速开关阀作为先导阀,控制大流量二通插装阀,组成无节流损失阀组,给出了插装阀的选择依据,并设计了滑阀式高压大流量二位三通高速开关阀。然后,建立了二位三通高速开关阀和二通插装阀以及能量吸收单元的数学模型,并在AMESim中进行了验证,利用AMESet开发了直线式步进电机的子模块;设定各模型参数之后,通过仿真分析了无节流损失阀控动力单元中主阀进、出油口压差以及能量吸收单元的特性,证明了主阀口打开时无节流损失,且避免了溢流损失,系统效率在90%以上。最后,研究了基于无节流损失阀控动力单元的位置控制及力控制,利用四个无节流损失阀组控制液压缸运动,打破了控制阀口之间物理结构上固有的耦合关系,给出了位置控制及力控制系统的仿真模型与相应的控制策略;在位置控制系统中分析了PWM控制频率、高速开关阀响应频率对系统控制性能及节能性的影响;在力控制系统中分析了三种不同控制逻辑下控制性能及节能性的优劣;通过阶跃响应及正弦响应证明了系统能在保证一定的控制精度的同时,可以大幅提高系统效率而达到节能的目的。本论文所进行的上述研究内容及取得的相应结果,为今后进一步开展相关的实际应用提供了理论上的依据。
[Abstract]:Compared with mechanical and electric transmission systems, hydraulic system has the advantages of high power density, easy to realize stepless speed regulation and overload protection, and is widely used in industrial control. However, there are a lot of throttling and overflow losses in traditional hydraulic systems. The efficiency of the system is only about 30%. Energy saving has become one of the problems that can not be ignored in the application and development of hydraulic technology nowadays. This paper starts from the angle of reducing throttling loss and overflow loss. A new concept of valve-controlled power unit without throttling loss is proposed, its realization mechanism is studied, a simulation model is established, and the control performance and energy saving of the force control system based on the position of the valve control power unit without throttling loss are analyzed. The main research work carried out in this paper are as follows:. Firstly, the energy saving technology commonly used in hydraulic system is summarized. Based on the reason of energy loss in traditional hydraulic system, the realization principle of valve-controlled power unit without throttling loss is analyzed. The high speed two-position three-way valve is used as the pilot valve to control the large-flow two-way cartridge valve and to form the valve group without throttling loss. The selection basis of the cartridge valve is given, and the sliding valve type high-pressure and large-flow two-position three-way high-speed switch valve is designed. Then, the mathematical models of two-position three-way high-speed switch valve, two-way cartridge valve and energy absorption unit are established and verified in AMESim. The sub-modules of linear stepping motor are developed by using AMESet, and the parameters of each model are set up. The characteristics of the main valve inlet and outlet pressure difference and the energy absorption unit in the valve control power unit without throttling loss are simulated and analyzed. It is proved that there is no throttling loss when the main valve opening and the overflow loss is avoided. The system efficiency is more than 90%. Finally, based on the position control and force control of the valve control power unit without throttling loss, the motion of the hydraulic cylinder is controlled by four valve groups without throttling loss, which breaks the inherent coupling relationship between the physical structure of the control valve port. The simulation model and corresponding control strategy of position control and force control system are given, and the influence of PWM control frequency and high speed switch valve response frequency on system control performance and energy saving are analyzed in the position control system. In the force control system, the advantages and disadvantages of control performance and energy saving under three different control logic are analyzed, and the step response and sinusoidal response prove that the system can guarantee a certain control precision at the same time. It can greatly improve the efficiency of the system and achieve the purpose of energy saving. The above research contents and the corresponding results obtained in this paper provide a theoretical basis for the further development of relevant practical applications in the future.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH134

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