直驱式电液调节阀稳压控制技术研究

发布时间：2018-12-13 00:45

【摘要】：目前钢厂已经利用生产中的废煤气循环发电,它节能又环保,但其中调节阀的稳压控制成为技术瓶颈。调节阀作为工业过程控制的终端元件,在调节系统中必不可少,广泛应用于石油、化工、电力、冶金等工业部门。由于节能减排、生态环保等日益受到重视,多种场合都要求调节阀具有更好的技术性能。然而目前国内调节阀仍以传统型式为主,响应慢、能耗高、控制精度差,因此亟需对新型高性能调节阀技术进行研究。本文分析了钢厂循环发电调节阀的性能要求并充分考虑推广其应用领域,结合液压传动与控制系统的新节能技术,以高效节能、结构紧凑、响应迅速、稳压精确为目标,开展了新型调节阀的设计研究。首先,设计了一种以直驱式容积控制(DDVC:Direct Drive Volume Control)电液伺服系统作为执行机构的新型高性能调节阀(以下简称“直驱式电液调节阀”)。拟定了液压系统原理,对系统主要元器件进行了匹配计算和选型。对比分析直驱式电液调节阀和传统调节阀后,突出了前者优势所在。同时在此基础上设计出一套结构紧凑的调节阀机械结构。其次,基于系统控制要求及特点,确立了以单片机为核心的控制方式,开发出一套基于PIC16F877单片机为控制核心的调节阀控制器。在硬件上完成了键盘输入、数据采集、数据存储、液晶显示、报警电路、伺服电机控制等电路模块的设计,控制器可内置于液压单元；在软件中利用MPLAB实现了调节阀的功能设定、伺服控制、开关状态三种控制模式,并且在C++Builder上编制了上位机界面,算法简单易行,程序执行速度快、功耗低。再次,根据直驱式电液调节阀的工作原理,进行了系统机理建模。分析了伺服电动机工作原理及泵控缸的流量特性和力平衡特性等,重点研究了调节阀门的流量、压力、开度及负载之间的关系,建立了直驱式电液调节阀系统的动态数学模型。推导出系统传递函数,在MATLAB环境下分析了系统稳定性,结果表明系统具有较大的稳定裕度。最后,提出了一种基于蚁群算法离线优化的模糊PID开关切换控制策略,应用于系统稳压控制。通过在MATLAB中编程模拟控制器工作状态的方式实现了更加精确的仿真,研究了系统在模糊PID开关切换和常规PID控制下的动静态性能,结果表明前者控制时系统的阶跃响应性能、方波跟踪能力、鲁棒性、抗干扰能力等均优于后者控制,且这些主要性能指标都能达到系统的设计要求。仿真结果表明,所设计的直驱式电液调节阀能满足高性能调节阀的使用要求。
[Abstract]:At present, the steel plant has made use of the waste gas in production to generate electricity, which is energy saving and environmental protection, but the regulating valve's steady pressure control has become the technical bottleneck. As the terminal component of industrial process control, control valve is necessary in regulating system and widely used in petroleum, chemical, electric power, metallurgy and other industrial sectors. Due to energy saving and environmental protection, more and more attention has been paid to regulating valve. However, at present, the traditional control valve is still the main type in China, which is slow in response, high in energy consumption and poor in control precision. Therefore, it is urgent to study the new type of high performance control valve technology. This paper analyzes the performance requirements of circulating power generation control valve in steel plant and fully considers its application field. Combined with the new energy-saving technology of hydraulic transmission and control system, it aims at high efficiency, compact structure, rapid response and accurate voltage stabilization. The design of the new control valve is studied. Firstly, a new type of high performance control valve (hereinafter referred to as "direct-drive electro-hydraulic control valve") with direct-drive volume control (DDVC:Direct Drive Volume Control) electro-hydraulic servo system as actuator) is designed. The principle of hydraulic system is worked out, and the matching calculation and selection of main components of the system are carried out. The advantages of direct drive electrohydraulic control valve and traditional control valve are highlighted. At the same time, a compact control valve mechanical structure is designed. Secondly, based on the control requirements and characteristics of the system, the control mode based on single chip microcomputer is established, and a set of control valve controller based on PIC16F877 microcontroller is developed. The keyboard input, data acquisition, data storage, LCD display, alarm circuit, servo motor control and other circuit modules are designed in hardware. The controller can be built into hydraulic unit. In the software, MPLAB is used to realize three control modes of control valve: function setting, servo control and switch state, and the upper computer interface is programmed on C Builder. The algorithm is simple, the program execution speed is fast, and the power consumption is low. Thirdly, according to the working principle of direct-drive electro-hydraulic control valve, the system mechanism model is built. The working principle of servo motor and the flow characteristics and force balance characteristics of pump control cylinder are analyzed. The relationship between flow, pressure, opening and load of regulating valve is studied, and the dynamic mathematical model of direct-drive electro-hydraulic regulating valve system is established. The system transfer function is derived and the stability of the system is analyzed under MATLAB environment. The results show that the system has a large stability margin. Finally, an off-line fuzzy PID switch switching control strategy based on ant colony algorithm is proposed, which is applied to the system voltage stabilization control. By programming in MATLAB to simulate the working state of the controller, a more accurate simulation is realized, and the dynamic and static performance of the system under the fuzzy PID switch switching and the conventional PID control is studied. The results show that the step response performance of the system is obtained when the former is controlled. The square wave tracking ability, robustness and anti-jamming ability are superior to the latter control, and these main performance indexes can meet the design requirements of the system. The simulation results show that the designed direct-drive electro-hydraulic control valve can meet the requirements of high performance control valve.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH137

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