下载后可任意编辑基于 PLC 和变频器串行通讯的变频恒压供水系统（摘 要）介绍了一种基于 PLC 和变频器采纳串行总线方式通讯的变频恒压供水系统的构成和工作原理。系统采纳变频调速方式自动调节水泵电机转速，保持供水压力的恒定，在用水低谷时投入小流量泵，降低电能损耗。变频器故障时仍能自动运行，保证不间断供水，同时故障消除后能自启动，实现无人值守全自动运行。（关键词）可编程控制器 变频调速 串行通讯 小流量泵（中图分类号）TP274 〔文献标识吗〕AFrequency Conversion Constant Pressure Water Supply System Based on PLC and Frequency Convertor With Serial Communication（ Abstract ） The composition and operational principle of an automatic frequency conversion constant pressure water supplying system based on PLC and frequency convertor with serial communication are introduced . The system adopts frequency conversion speed regulating measure to adjust rotating speed of the motors of water pumps ，and to keep the press constant .This system can startup the little pump at the vale of using water to saving power . System can still operates automatically with failure of frequency conversion to obtain uninterrupted water supply and can be auto startup after system recovery , this creates the possibility of fully automatic operation. （Key Word） PLC Frequency conversion and variable speed serial communication low flow pump在居民生活用水、工业用水、各类自来水厂、油田、油库、锅炉定压供热和恒压补水喷淋及消防等供水系统中，采纳传统的水塔、高位水箱、气压增压等设备，不但占地面积和设备投资大，维护困难，且不能满足高层建筑、工业 、消防等高水压、大流量的快速供水需求。另一方面，由于供水量的随机性，采纳传统方法难以保证供水的实时性，且水泵的选取往往是按最大供水量来确定 ，而高峰用水时间较短，这样水泵在很长一段时间内有较大余量，不仅水泵效率低，供水压力不稳，而且造成大量电力浪费。这里介绍一种由可编程控制器控制的变频恒压供水系统，它既能解决人工操作的繁杂劳动和精神压力，又能...
