Based Scada Principles Of City Gas Network Security Monitoring System Design And Implementation,

With the completion of the west-east natural gas project, our country goes into an era when natural gas is used in cities. To ensure municipal natural gas pipeline to run in a safe, even and effective way, it becomes a vital part of the safe production for the municipal gas corporations to set up a set of pipe networks monitoring system which is used for the automatic collection, arrangement, conveyance, analysis, classification and storage of the networks' running information and pipe networks conditions and the internal management of the gas corporations.This system, which is based on the basic principles of SCADA (Supervisory Control and Data Acquisition) system, is a comprehensive municipal gas networks monitoring system for safety, which combines modern measuring technique, computer technique, GPRS wireless grouping data communication technique, configuration software technique, distributive computer networks and large-scale relation database technique. It can be used to build mathematical model of the running state of the pipe networks, to simulate the real operational conditions of the networks using real-time data, to calculate runoff, stock, temperature, pressure and distributing state in every segment of the pipe. It can also be used to find out the running performance of the networks through systematic analysis, to predict future supply-demand situation and the leaking situation of the natural gas pipe networks, to optimize the conveyance of the gas.Because the quantities of the gas supply per day of the gas corporation present a wavy distribution in time and the consuming quantities change fast, the system has a high demand on the real-time property of the networks data. Furthermore, the municipal networks distributes vast, with its large quantities of collection points and some in remote areas. It becomes a parameter clause for the system' successful operation to convey the data collected from the monitoring points to the controlling center in a real-time and effective way. GPRS wireless data grouping service is chosen as the optimum communication means through the comparison between such wired communication means as DDN, ADSL, ISDN, PSTN and optical cables and such wireless communication means as super short-wave station, microwave, spread spectrum, satellite, GSM short messages and GPRS data grouping service in communicational principles, technical characteristics, systematic stability, systematic cost, install characteristics and running expenses.In this test, we study the development of RTU (Remote Terminal Unit) configuration software, the treatment of the GPRS wireless data terminal and GPRS internet data attachment protocol, the interconnect method designment of the GPRS changing center and its data controlling center, the internet cutover of the data center and the designment of the applied software in conveying process, the development of the person-computer interface configuration software of the controlling center and the transfer of the relational database. We discuss the conveying method of the data from many GPRS data terminal to the data-controlling center, the sending protocol of the data and controlling orders and the packetization of the data in an important way.