| Water supply is concerned with national economy and people's life. With the development of the economy of our country and the continuous improvement of living standard, people demand better water supply quality and reliability of water supply system. The conflict between urban water supply and requirement is becoming more and more outstanding, so quickening the urban water supply development is becoming an urgent matter for the moment. It is a very important subject that how to use the water properly, and how to make the development of the economy and society match the water supply.As an effective measure to ensure secure, continuous and high quality water supply, the water plant automatic control system makes great sense. It is an inevitable tendency to design a powerful and energy-saving water supply system, using advanced automation technology, communication technology, control technology and control theories.The water supply system is composed of pumping water from water source, increasing pressure at boost stations, supplying water under constant pressure at Second Water Plant and storing and supplying water at First Water Plant. All sections distribute dispersedly, locating long distance from each other. According to these properties, a SCADA system was designed with automatic control technology, communication technology, sensing technology and computer technology. In this SCADA system,wire communication is used between the Second Water Plant and the control center for the short distance, while wireless communication which links to each communication equipment with 485 bus is used between control center and boost stations, water source, the First Water Plant and the control center for the long distance.Because the well group of water source dispersedly distributed, every well house has a wireless data transceiver, RTU and EDA to gather information about water source well flux, warning and electricity parameters, and pumps can be controlled remotely.The duty room of water source, boost stations and the First Water Plant communicate with the control center by wireless data transceiver, and S7-200 PLC is used to gather data on water level, flow rate and pressure and control pumps and valves.At the Second Water Plant, which is in charge of the urban area water supply under constant pressure, a fully automatic frequency conversion constant pressure water supply and remote monitoring system was designed with PLC, frequency inverters, teletransmission pressure gauges, multi-pump set and computer, and this system has many functions such as fully automatic frequency conversion constant pressure running, automatic power frequency running, remote manual control and local manual control. The control system adopting STEP7-Micro/Win3232 software designs a water supply system PID controller embedded in PLC. The controller processing the difference between set value and measuring value timely controls the output voltage and frequency of frequency inverter, so that it can control the outlet's flow rate by controlling motor's rotate speed of the pump, realizing the pipe network's pressure automatic regulation and making the pipe network's pressure around the set value.In order to implement the whole water supply remote monitor, in the Second Water Plant central control room a configuration software was placed in an industrial computer to collect data and monitor each section of the water supply.The system selected Beijing Asia Control Company's KINGVIEW 6.52 software to configure the whole water supply system. Based on KINGVIEW explore environment, the configuration project has friendly interface, simple operation and plentiful graphs, and is able to show the dynamic situation of the local equipments by animation.This automatic water supply control system has run in Shan Yin County Water Plant Company, Shanxi province for more than one year, and this plan is propitious to increase the urban water supply automation level and realizes stable and efficient water supply from the water plant's running effect. |
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