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吉林农业大学学士学位论文论文题目：变频调速恒压供水系统的设计学生姓名：包旭东专业年级：自动化06级指导教师：胡俊海职称讲师年月日目录摘要··········································································································11前言·········································································································11.1变频调速技术概况···················································································11.2变频调速恒压供水系统产生的背景及研究意义··········································11.2.1传统供水方式························································································21.2.2变频调速恒压供水节能分析···································································21.2.3研究意义······························································································51.3变频调速恒压供水系统的发展········································································51.4本文主要研究内容···················································································62单片机概述································································································62.1单片机简介······························································································62.2单片机的发展史·······················································································72.3单片机的发展趋势····················································································82.4AT89C51单片机简介················································································93变频调速恒压供水系统的工作原理·····························································93.1变频调速的基本原理··············································································103.1.1变频调速的基本控制方式·········································································103.2系统工作过程························································································113.3系统的参数选取及调速范围···································································134变频调速恒压供水系统的硬件设计····························································134.1主控单片机引脚说明··············································································144.2反馈压力检测电路··················································································154.3输出控制电路························································································164.4控制输入电路························································································174.5系统电压监控及Watchdog电路······························································175变频调速恒压供水系统的软件设计····························································185.1单片机接口地址分配和控制端口功能······················································185.2软件程序设计························································································186结论·········································································································21参考文献·····································································································21致谢··········································································································22附录············································································································23吉林农业大学学士学位论文（设计）变频调速恒压供水系统的设计1变频调速恒压供水系统学生：包旭东专业：自动化指导教师：胡俊海摘要：随着社会经济的飞速发展，城市建设规模的不断扩大，人口的增多以及人们生活水平的不断提高，对城市供水的数量、质量、稳定性提出了越来越高的要求。建设节约型社会，合理开发、节约利用和有效保护水资源也是一项艰巨任务。因此，有利于节能节水的变频调速恒压供水系统得到了更广泛的应用。本文论述了变频调速恒压供水系统的调速原理及节能分析。描述了变频调速恒压供水系统的设计和实现方法。本文提出的系统设计方案是以ATMEL公司的AT89C51为基础，同时描述了包括变频器和传感器在内的硬件控制系统和相应的软件控制系统。充分发挥了单片机成本低，易于使用的特点。关键词：变频调速；恒压供水；AT89C51单片机1前言1.1变频调速技术概况变频技术是利用大功率半导体器件及其相应的控制与保护电路来实现电能频率参量的控制与变换，以实现电力的某些使用目的，并提高其使用质量与效率的一种技术。变频技术在经历了早期电子管、晶闸管整流器（60年代）和集成电路技术（70年代）几个阶段后，从80年代至今一直沿用基于电力电子技术的功率集成电路技术，并随着技术的进步继续发展[1]。而变频调速技术就是在变频的基础上调整电机转速的技术，其基本原理是根据电机转速与工作电源输入频率成正比的关系：n=60f（1-s）／p，（式中n、f、s、p分别表示转速、输入频率、电机转差率、电机磁极对数）；通过改变电动机工作电源频率实现转速的改变。变频调速技术已深入我们生活的每个角落，在国民经济和日常生活中占有重要地位:应用面广，是工业企业和日常生活中普遍需要的新技术;是节约能源的高新技术;是国际上技术更新换代最快的领域;是高科技领域的综合性技术。交流变频调速技术，已成为国内外公认的最理想、最有发展前途的电机调速方式。经测算，电机采用变频调速技术运行后，一般可节电20%一40%，因此这项技术具有广阔的使用前景，可被广泛应用于改造锅炉、风机、水泵、制冷机等设备的运行方式，以用来降低压差损耗以及起停电吉林农业大学学士学位论文（设计）变频调速恒压供水系统的设计2机的电耗[2]。我国现有的100万kw以上的大型电厂中，每套30万kw的发电机一般都配备30-35台辅机驱动用电动机。一个大型电厂，其辅机电动机多达250台左右。火力发电厂用电动机驱动的辅机主要是风机水泵、给水泵、循环水泵、空压机和磨煤机等，据初步调查，其中50%-60%的风机、水泵可以改为调速运行。如果这些设备都实现变频调速运行，按节电20%计算，年节电可达200亿kW.h，相当于装机400万kw容量的发电设备[3]。因此，应用电力电子的交流变频调速装置以及相关高新技术来改造传统的产业，就可以获得很好的社会效益和经济效益。近几年来，随着电力电子技术、计算机技术、自动控制技术的迅速发展，电气传动技术面临着一场历史革命，即交流调速取代直流调速、计算机数字控制技术取代模拟控制技术已成为发展趋势。在这种环境下，电机交流变频调速技术已经逐渐发展成为当今世界节电、改善工艺流程以提高产品质量、改善环境以及推动技术进步的一种主要手段。1.2变频调速恒压供水系统产生的背景及研究意义我国国民经济正处于迅猛发展时期，能源紧缺是制约我国经济发展的重要因素，节能节水是我国经济持续发展的基本国策。另外，随着社会经济的飞速发展，城市建设规模的不断扩大，人口的增多以及人们生活水平的不断提高，对城市供水的数量、质量、经济、稳定性提出了越来越高的要求[4]。供水质量的好坏直接影响着人民的生活水平和企业的生产效率。要安全、稳定、经济可靠的管理好遍布全城的供水管网，一定要有一个满足供水特点的、先进的自动化供水控制系统。但我国长期以来在城市供水、楼宇供水、工业生产供水等方面技术一直比较落后，自动化程度低，效率低下。究其原因，主要是由于受供水设备和供水方式的限制。1.2.1传统供水方式1.恒速泵直接供水方式这种供水方式，水泵从蓄水池中抽水加压直接送往用户，有的甚至连蓄水池也没有，直接从城市公用水网中抽水，严重影响城市公用管网压力的稳定。这种供水方式，水泵整日不停运转，有的可能在夜间用水低谷时段停止运行。这种系统形式简单、造价最低，但耗电、耗水严重，水压不稳，供水质量极差。2.水塔/水箱的供水方式这种方式是水泵先向水塔或水箱供水，再由水塔或水箱向用户供水。这种供水压力比较恒定，且有贮水。但它是由位置高度形成的压力来进行供水的，为此，需要建造水塔或将水箱置于建筑物的顶部[5]。即使如此，在