智能電纜防火的警報系統設計畢業論文(已修改)

　

【正文】 摘　　要引起電纜火災的直接原因是電纜中間頭制作不良、壓接頭不緊，長期運行造成電纜頭過熱而燒穿絕緣，導致火災發生。目前全國運行的電力電纜故障 80%以上是由于電力電纜附件引起的，其中電纜接頭引起的事故占一半以上。據有關部門統計，在我國發生的多次電纜火災事故中直接和間接損失巨大。電纜火災事故嚴重影響發電廠和變電站的安全運行，所以對電纜防火進行探討有十分重要的意義。研究設計電力電纜火災在線監測系統就是為了能夠實時監測電力電纜的溫度變化,在溫度越限或溫升速度越限時能及時報警,并指出發熱點位置(溫度探頭位置),通知運行人員及時處理,從而保證運行安全,避免經濟損失。針對電纜火災故障的特點，本次設計將針對該課題進行初步的探討。本文針對變電站、發電廠電纜溝中的電纜防火問題，設計出了電力電纜火災在線監測系統，該系統是以 DS18B20 為溫度數據采集芯片，以MAX1480B 為通訊芯片的溫度巡檢系統，結合離子感煙技術和可視化技術。可有效監測電纜溝中的電纜溫度和環境狀態，防止電纜火災、保障電力生產的安全運行，因此該系統具有極其重要的理論意義和實際價值。關鍵詞：溫度巡檢系統；串行通訊；DS18B20；MAX1480BAbstractCable caused the direct cause of the fire is among the first cable produced adverse pressure connector, and do not longrunning causing the cable to the first overheating burn through insulation, leading to fires. At present operation of the electricity cable fault is 80% above the electric cables of the annex, cable connector which caused the accidents account for more than half. According to the statistics made by the departments, indirect and direct loss is great in the numerous cables fire accident that takes place in China. The fire accident of the cable influences the safe operation of the power plant and transformer substation seriously. So it has great importance take cable fire prevention into research. Design fire power cable online monitoring system is to be able to monitor realtime electricity cables, the temperature change the temperature or temperature limit speed limit can be more timely warning, and pointing out that the location of the hot (temperature probe location). notify the operational personnel handled in a timely manner, so as to ensure safe operation and avoid economic losses. Cable Fault fire against the characteristics of this design will address the subject of preliminary discussion. In order to solve the fire prevention issue of cable in the cable trench of transformer substation and power plant, we developed the Electric Cable Fire Online Monitoring System. This temperature measuring system based on the temperature data acquisition chipDS18B20 and the serial munication chip addition to the Visualization Technology and Ionic smoke sensing technology. It can monitor the cable temperature in the cable trench and environmental state effectively, prevent the cable fire, ensure the safe operation of electric power production, so the electric cable online monitoring system has great significance in theory and practical value.Keywords: Temperature Measuring System。 serial munication。 DS18B20。 MAX1480B 目　　錄摘　　 要 ..................................................................................................................IABSTRACT...........................................................................................................II目　　 錄 ...............................................................................................................III第 1 章 緒　　 論 ....................................................................................................1 課題背景及意義 ...........................................................................................1 火電廠發生電纜火災的特點 ................................................................1 引起電纜火災的原因 ............................................................................2 電纜防火的主要問題 ...................................................................................2 主要應對方案 ...............................................................................................3 電纜防火的特點及發展趨勢 ........................................................................4 目前火災探測領域的主要熱點 .............................................................4 電纜防火的發展趨勢 .............................................................................5第 2 章 系統的總體結構分析 ................................................................................8 系統的總體結構 ...........................................................................................8 系統的工作原理 ...........................................................................................8 串行通信模塊 ........................................................................................8 子站的硬件設計 ....................................................................................9 溫度數據的采集 ...........................................................................................9 溫度傳感器特性 ..................................................................................10 DS18B20 設計中存在的幾個問題 ......................................................13 ROM 操作指令及其含義 .....................................................................14 存儲器操作指令代碼及其含義 ..........................................................14 煙霧監測 ....................................................................................................15 煙霧監測原理 ......................................................................................15 離子感煙器的詳細介紹 ......................................................................16第 3 章 系統多機通訊及接口 ..............................................................................18 RS－232 與 RS－485 接口的特點 .............................................................18 多機通訊原理 .............................................................................................18 多機通訊的軟件協議 .................................................................................19 MAX1480B 通訊接口芯片 .........................................................................19第 4 章 下位機硬件組成及通訊原理 ..................................................................24 下位機硬件組成 .........................................................................................24 溫度傳感器單線通訊原理 .........................................................................24 下位機軟件流程 ..................................................................................26 溫度數據轉換 ......................................................................................27 串行通訊方式的選擇 ...............