变频液压系统特性研究及限速切断阀研制

【作者】 张一丁；

【导师】 杨华勇；

【作者基本信息】 浙江大学 ， 机械电子控制工程， 2003， 硕士

【摘要】 变频调速技术是目前国际最流行、应用最广泛的调速技术之一，对液压技术来说，如何汲取变频调速技术的优点是极其重要的课题，因此研究变频驱动液压系统的特性也就变得十分重要。论文中第一章介绍了变频技术的国际发展状况，以及在液压系统中的应用，第二章里建立了详尽的变频液压系统数学模型，尤其是对变频器电机环节的模型，分别建立了变频器的变频变压控制方式和先进矢量控制方式两种模型，利用Matlab的时域仿真功能，对模型进行了仿真，对比分析了系统不同参数情况下的系统阶跃响应情况，得到了一些有意义的结论，然后通过相应系统实验验证了仿真模型，并通过实验数据研究，结合理论分析，进一步说明了变频驱动液压系统的一些特性。 限速切断阀是液压电梯中的安全保护阀，它能够在液压电梯系统出现异常情况时关闭系统，起到保护作用。本文在第一章对限速切断阀的原理进行了简介，并分析了国内外的研究现状，以及介绍了欧洲《液压电梯制造与安全安装规范》中对限速切断阀的要求。 第三章主要论述了限速切断阀阀芯结构的选型、以及整套阀的设计过程。其中阀芯的设计选型与确定过程中，利用了fluent流场专用仿真工具，对几种不同限速切断阀的阀芯内部流场情况进行了分析，指导了设计过程，最后设计出了比较合理的阀芯结构。根据流场仿真的结果，设计了三角开口的阀芯，阀口由圆柱面切割而成，并进行了分析验算。阀的设计包括计算、检验及出图，除了用AutoCAD完成了全套图纸外，还利用Pro／E软件进行了模拟装配。 第四章针对限速切断阀建立了它在液压电梯系统中的数学模型，并利用Matlab仿真软件对该阀在电梯系统中的阶跃响应特性进行了研究，对比分析了限速切断阀内部各参数对其性能的影响，尤其是液阻、阀芯结构参数和弹簧刚度这些关键结构参数。另外，在液压电梯不同的工况下，对该阀的动态性能进行了仿真对比研究，如不同环境温度、不同乘客人数、不同液压系统意外，以及不同的油液体积弹性模量，比较全面系统的分析了限速切断阀在电梯系统中的性能，根据这些仿真结果，可以分析该阀正常工作的工况要求和环境要求。 第五章首先介绍了限速切断阀的实验方案与实验台架，由于本实验涉及限速切断阀的较多性能，因而采用了两种不同的实验设备。然后分析了实验结果，并对动态实验数过与仿真结果进行了对比研究，一方面验证了仿真的结论，一方面得到了一些有价值的结论，最后分析实验结果，考核该阀是否符合欧洲《液压电梯制造与安全安装规范》中对限速切断阀的要求。 纵观全文，作者首先对变频驱动液压系统(包括泵控缸和泵控马达)建立了数学模型，对变频器不同的控制方式也分别进行了建模，然后对系统参数进行了仿真对比分析，并从实验中对仿真结果进行了验证。然后针对液压电梯专用限速切断阀，通过fluent流场仿真软件和Matlab仿真软件的分析，建立了一套比较完整的设计计算的方法；采用三维造型软件对限速切断阀进行了实体建模，改变了传统的结构设计方法，使限速切断阀的结构设计达到了更好的效果；利用专门的电液元件测试平台和液压电梯台架对限速切断阀进行了比较全面的实验，拓展了新元件的实验研究手段。限速切断阀部分对液压电梯技术的实用化和产品化具有重要的意义。更多还原

【Abstract】 For hydraulic technique, how to acquire the merits of the motor speed regulation technique is such an important subject that it becomes very important of studying on the characteristics of the hydraulic system with motor speed regulation.In chapter 1 the state-of-the-art of the motor speed regulation technique and its application in the hydraulic system is introduced. In chapter 2 a math model of the hydraulic system with motor speed regulation is built, in which the author builds the model of the converter-electromotor with two different modes, the VVVF control and the Advanced Vector Control. Using Matlab, these models is simulated and, after comparing the results of system step response with different system parameters, some useful conclusions is drawn. Then, through relevant experiments data study and theory analysis analyze some characteristics of the hydraulic system with motor speed regulation.Pipe Rupture valve is able to close itself in the event of failure in the main cylinder line or where the down speed exceeds allowable limits in the hydraulic elevator system. In chapter 1 the principle and the research status of the pipe rupture valve and the requirement of the pipe rupture valve in the European Hydraulic Elevator Manufacture and Secure Installation Standards (EN81-2) are also introduced.In chapter 3 dissertates the selection of the pipe rupture valve and the design process of the complete set of the valve. Especially in the design and the selection of the valve, using the simulation software-fluent, the internal flow field of some kinds of different pipe rupture valve are analyzed. And a reasonable structure of valve is worked out. The design of the valve includes calculating, checking, and drawing. The blueprints are all made by AutoCAD and the installation is emulated by Pro/E.In chapter 4 a math model of the pipe rupture valve for the hydraulic elevator system is built. Using Matlab, the step response characteristics of the valve in the elevator system is simulated, comparing the effect of its performance with different structure parameters of the pipe rupture valve, such as hydraulic resistance, diameter of the valve, and spring rigidity, and comparing the valve’s dynamic performance under different operating conditions, such as environment temperatures, number of passengers, and emergencies of the hydraulic system, so the paper offers a general and systematic analysis for the pipe rupture valve of the elevator system. These simulation results can be used to analyze the operating conditions and environment requirements for nominal working.In chapter 5 the experiment rigs are introduced first. Because the experiments would concern many performances of the pipe rupture valve, there are two different sets of experiment rigs. Then the results of the experiment is analyzed and compared with the simulation results. On the one hand, it satisfies the simulation conclusions; on the other hand, it draws some useful conclusions. Finally, ensures whether the valve satisfies the requirements of the EN81-2.Conclusively,math model for the hydraulic system with motor speed regulation is built first, including the hydraulic cylinder system and the hydraulic motor system, and the different control mode for the converter too. Then the system parameters are analyzed by simulation comparison with relevant experiments. After that, a complete solution to design the pipe rupture valve of the hydraulic elevator with fluent and Matlab simulation software; deserting the traditional method,gives a solid modeling for the pipe rupture valve with the 3-D CAD software which offers greater effects for the structure design of the pipe rupture valve; Using special electro hydraulic and hydraulic elevator experiment rig, the pipe rupture valve is completed test. The pipe rupture valve has important significance for the utilization and production of the hydraulic elevator technique.更多还原