目录摘要IABSTRACTII绪论11 变频恒压供水系统介绍21.1 变频恒压供水系统意义和目的21.2 变频恒压供水系统的优点22 变频恒压供水的理论分析42.1 水泵的工作原理42.2 供水电机的搭配42.3 恒压供水系统的能耗分析52.4 供水系统的安全性问题72.4.1 水锤效应72.4.2 水锤效应的产生原因72.4.3 水锤效应的消除82.4.4 延长水泵寿命的其他因素83 变频恒压供水控制系统硬件的设计93.1 变频恒压供水控制系统的构成方案93.2 变频恒压供水系统的控制方案103.3 参数的计算与供水设备选型113.3.1 水泵的参数计算与型号的选择113.3.2 变频器的选择113.3.3 压力传感器的选择133.3.4 水位传感器的选择143.3.5 其他低压电器的选择143.4 PLC的选型153.4.1 I/O点的统计153.4.2 PLC选型的基本原则163.4.3 I/O的分配163.5 系统硬件线路设计173.6 PID参数的预置184 变频恒压供水控制系统软件的设计204.1 逻辑代数设计法204.2 编程软件的简单介绍204.3 恒压供水系统梯形图的设计214.4 经济效益分析255 总结与期望265.1 总结265.2 展望26参考文献27致谢29附录 语句表30摘要随着我国社会经济的发展，城市建设发展十分迅速，同时也对基础设施建设提出了更高的要求。城市供水系统的建设是其中的一个重要方面，供水的可靠性、稳定性、经济性直接影响到用户的正常工作和生活。随着人们对供水质量和供水系统可靠性要求的不断提高，利用先进的自动化技术、控制技术以及通讯技术，设计出高性能、高节能、能适应供水厂复杂环境的恒压供水系统成为必然趋势。本文首先根据管网和水泵的运行特性曲线，阐明了供水系统的变频调速节能原理；具体分析了变频恒压水供水的原理及系统的组成结构，通过研究和比较，得出结论:变频调速是当今国际上一项效益最高、性能最好、应用最广、最有发展前途的电机调速技术。因此本文以采用变频器和PLC 组合构成系统的方式，以某居民小区水泵电动机控制系统为对象，逐步阐明如何实现水压恒定供水。主要进行了控制系统的主电路设计，控制电路设计。对输入输出点进行了统计，共有13个输入输出点，根据PLC的选型原则，设备选用了在生产中应用最为广泛的西门子公司生产的S7-200系列(CPU222)的PLC和MM430泵类专用的变频器，利用变频器的本身自有的软启动功能实现水泵电机的启动。在控制过程中，电控系统由S7-200完成，PID控制由变频器的内置PID控制方式完成，根据控制系统软硬件设计和控制要求，结合变频器的功能参数表预置了相关的参数。在介绍了PLC的编程方法的基础上，选用了适合初学者的逻辑代数编程，写出了恒压变频供水的逻辑代数，并设计了梯形图。最后对恒压供水进行了经济效益分析，分析的结果表明具有明显的节能效益。关键词：恒压供水，变频调速，PLC，设计ABSTRACTAs Chinas social and economic development, urban construction and development very quickly, but also the construction of infrastructure facilities has put forward higher requirements. City water supply system construction is one of the important aspects of the water supply reliability and stability, the economy of a direct impact on the users normal work and life. As people on the water quality and water supply systems in the continuous improvement of reliability requirements, the use of advanced automation technology, control technology and communication technology, design a high-performance, high-energy, water supply plants to adapt to the complex environment of constant pressure water supply Systems become an inevitable trend. Firstly, according to the operation of pipeline and pump characteristic curve illustrates the energy supply system frequency control theory; detailed analysis of the principle of variable frequency and constant pressure water supply system of the structure, through research and comparison, concluded: frequency modulation Speed is a benefit on todays international, highest performance, most widely, the most promising of the motor speed control technology. This article combined to constitute a frequency converter and PLC systems approach to a residential area for the object pump motor control system, step by step to clarify how to achieve constant pressure water supply. Mainly for the control system design of the main circuit, control circuit design. The input and output points to the statistics, a total of 13 input and output, the PLC in accordance with the principle of selection, equipment selection in the production of the most widely produced by Siemens S7-200 series (CPU222) of the PLC and pumps for MM430 The converter, using its own frequency converter itself to achieve the soft-start the pump motor launch. In the control process, the electronic control system completed by the S7-200, PID control by the converter built-in PID control manner, in accordance with control system software and hardware design and control requirements, combining the functions of converter table preset parameters of the relevant parameters. After the introduction of the PLC programming methods, based on the choice of the logic of algebra for beginners programming, the constant pressure to write the logic of algebra frequency of water supply and design of the ladder .The results show that the correctness of the design process. Finally, constant pressure water supply to an economic analysis, analysis showed that a significant energy saving benefits.Key words: Water Supply Frequency Control PLC design朗读显示对应的拉丁字符的拼音字典可翻译 50 多种语言 s t Cmo ests? escargots Vr s snill hello . Ich bin vierzig Jahre alt ! Wie bitte? Wie heien Sie? haydi gidelim miracoloso rouge Wie gehts? hoje est ensolarado Je ne sais pas ! dti nazdar! Je parle un petit peu franais. Pardon ? Buongiorno Principessa! Hjelp! mijn vriend La voiture Es ist sehr interessant!使用“Google 翻译”，您还可以：I绪论随着社会经济的迅速发展，水对人们的生活和工业生产越来越重要，人们对供水的质量和安全可靠性的要求不断提高。而用户的用水量是不断变化的，导致供水不足或供水过剩的情况时有发生。而用水和供水之间的不平衡集中反映在供水压力上，即用水多而供水少，则压力低；用水少而供水多，则压力大。保持供水压力的恒定，可使供水和用水之间保持平衡，即用水多时供水也多，用水少时供水也少，从而提高了供水的质量。人民生活水平的日趋提高，新技术和先进设备不断地应用 ，使给供水设计得到了发展的机遇，当前住宅建筑的小区规划趋向于更具人性化的多层次住宅组合，不再仅仅追求立面和平面的美观和合理，而是追求空