基于电场测量的起重机防触电报警系统

Electric shock-proof alarming system of crane based on field measurement

本系统是一种便于在各种起重机设备上安装的距离监测防触电报警制动装置,按功能分为探测模块和接收模块两部分。基于简单可靠的测量方法,探测模块将高压场强信号转换为易处理的电压信号,再进行衰减、整形、滤波,得到与电场强度对应的直流信号。利用高效片上系统C8051F020进行A/D转换,再通过无线电通讯系统把监测到场强信息发送到安装在驾驶室的接收模块。该装置的接收模块能接收多个感应探头的信号,应用时将感应探头安装在起重机各凸出部位。接收模块分析处理接收到的各个感应探头的信息,在智能大液晶屏上,用红、黄、绿彩色矩状的变化,形象的显示起重机各突出部位离场源的距离。一旦起重机设备的某凸出部位与带电体距离小于国家规定的安全距离时,所感应到场强会超过设定值,装置会发出预警、报警信号,同时能控制继电器断开电源,强行制动停止起重设备作业。实现可靠的安全保护。本系统的探测部分采用了有效的屏蔽措施,经过测试,能在30—220kV的高压电场环境中正常工作。

This system was a vemote monitoring alarm brake device against electric shock. The device could be widely used in a variety of crane equipments. This system consisted of two parts：detector module and receiver module. Through simple and reliable measuring methods, the detector module transformed high-voltage field strong signals into voltage signals, which were more easily to process. After being magnified, shaped and filtered, the voltage signals could produce DC signals of corresponding electric field strength. Using the high efficiency SoC C8051F020 to do the AD transform, the device sent the information to the receiver module installed in the tractor cab through wireless transceiver. The receiver module of the device could receive signals from several inductive probes. The inductive probes should be installed on the protruding points of the hoisting machinery. The receiver module analyzed and pro- cessed all the data received and displayed the results on LCD panel using red, yellow and green rectangular pattern. The pattern could show the distance between protruding points and field source visually. Once the distance between the protruding points and the surrouding charged object less than a safe distance, the device would give out a warning signal while the control relay will switch off the power to forcibly stop the operation, thus provided reliable security for working labor. The detecting module adopted effective shielding measures. Experiment results indicated that the system functions normally in the High-voltage Electric Field ranging from 30KV to 220KV.