调节阀直驱式电液执行机构的研究

发布时间：2018-03-17 00:23

本文选题：调节阀执行机构　切入点：DDVC　出处：《山东大学》2011年硕士论文　论文类型：学位论文

【摘要】：调节阀是工业过程控制中最常用的控制元件之一,广泛应用于化工、冶金、核电、火电等工业部门。随着科技的发展和社会的进步,工业控制的系统化、智能化不断提高,节能减排日益受到重视,对调节阀的技术性能要求也就越来越高。执行机构是调节阀的关键部件,对调节阀的性能起着决定性影响。然而传统执行机构响应速度慢、能耗高、抗负载干扰能力弱,限制了调节阀性能的提高。因此,亟需研究新型执行机构以提高调节阀的动静态性能。本文全面总结分析了调节阀执行机构的工作原理及特点,以提高执行机构抑制负载干扰能力、增大输出推力和速度为目标,开展了新型调节阀执行机构的设计研究。首先,研究了调节阀电液执行机构的工作原理及优缺点,将DDVC(直驱式容积控制,Direct Drive Volume Control)电液伺服系统应用于调节阀电液执行机构,得到了一种新型电液执行机构——DDVC电液执行机构。阐述了DDVC电液执行机构的工作原理,分析了其对于传统电液执行机构的优点。同时对DDVC电液执行机构进行了系统设计及元器件设计选型,初步实现了集成化结构设计的目标。其次,基于齿轮泵的工作原理,对双向齿轮泵进行了理论研究。通过内部集成单向阀实现了齿轮泵的双向工作。分别将齿轮泵压油腔、吸油腔中的高压油、低压油引入相应的补偿腔,实现了轴向间隙和径向间隙的自动补偿,减少了泄漏,提高了容积效率和工作压力。再次,根据DDVC电液执行机构的工作原理,进行了系统机理建模。通过分析伺服电动机调速系统电压-转速特性及双向齿轮泵控双出杆对称液压缸的流量特性和力平衡特性等,建立了DDVC电液执行机构的动态数学模型。在MATLAB环境下分析了系统稳定性,结果表明系统稳定,并且具有较大的稳定裕度。最后,利用MATLAB/Simulink,对DDVC电液执行机构进行了控制策略仿真研究,对比分析了系统分别采用PID控制和PID校正的最优状态全反馈与观测器预估干扰相结合的复合控制时的性能。仿真结果表明,采用PID控制系统的超调量和稳态误差均较小,但快速性较差,抑制负载干扰的能力弱,静态性能较差；而采用PID校正复合控制后,响应速度得到明显提高,抑制负载干扰的能力得到加强,动静态性能均得到了很大提高。通过与国外相关产品的比较,所研究的DDVC电液执行机构的综合性能达到了国外产品的水平,有些指标甚至优于国外产品,能够满足高性能调节阀的使用要求。
[Abstract]:Control valve is one of the most commonly used control components in industrial process control. It is widely used in chemical, metallurgical, nuclear, thermal power and other industrial sectors. With the development of science and technology and the progress of society, the systematization and intelligentization of industrial control are continuously improved. More and more attention has been paid to energy saving and emission reduction, and the technical performance requirements of the control valve are becoming higher and higher. The actuator is the key component of the control valve, which plays a decisive role in the performance of the control valve. However, the traditional actuator is slow in response and high in energy consumption. The capability of resisting load interference is weak, which limits the performance of the control valve. Therefore, it is urgent to study the new actuator to improve the dynamic and static performance of the control valve. In this paper, the working principle and characteristics of the actuator are summarized and analyzed. In order to improve the capacity of the actuator to suppress the load interference and increase the output thrust and speed, the design of the new actuator of the regulating valve was studied. Firstly, the working principle, advantages and disadvantages of electro-hydraulic actuator of regulating valve are studied. DDVC (Direct Drive Volume Control) electro-hydraulic servo system is applied to electro-hydraulic actuator of regulating valve. A new type of electro-hydraulic actuator, DDVC electro-hydraulic actuator, is obtained. The working principle of DDVC electro-hydraulic actuator is described. The advantages of the traditional electro-hydraulic actuator are analyzed, and the system design and component selection of the DDVC electro-hydraulic actuator are carried out. The goal of the integrated structure design is preliminarily realized. Secondly, based on the working principle of gear pump, a theoretical study is carried out on the bidirectional gear pump. The bidirectional operation of gear pump is realized by the internal integrated unidirectional valve. The low pressure oil introduces the corresponding compensation cavity to realize the automatic compensation of the axial and radial clearance, reduces the leakage, improves the volumetric efficiency and the working pressure. Thirdly, according to the working principle of the DDVC electro-hydraulic actuator, the system mechanism is modeled. By analyzing the voltage-speed characteristics of the servo motor speed regulating system, the flow characteristics and the force balance characteristics of the double-rod symmetrical hydraulic cylinder controlled by the bidirectional gear pump, etc. The dynamic mathematical model of DDVC electro-hydraulic actuator is established. The stability of the system is analyzed under the MATLAB environment. The results show that the system is stable and has a large stability margin. Finally, the control strategy of DDVC electro-hydraulic actuator is simulated by MATLAB / Simulink. The performance of the optimal state full feedback combined with observer predictive disturbance control with PID control and PID correction is compared and analyzed. The simulation results show that the overshoot and steady-state error of the PID control system are small. However, the speed is poor, the ability to suppress the load interference is weak, the static performance is poor, and the response speed is obviously improved and the ability to suppress the load interference is strengthened by using the PID correction compound control. The dynamic and static properties have been greatly improved. Compared with the related products from abroad, the comprehensive performance of the DDVC electro-hydraulic actuator studied has reached the level of foreign products, and some indexes are even better than those of foreign products. Able to meet the requirements of high performance regulating valve.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH137

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