基于LabWindows/CVI的故障电弧在线检测系统的设计

Design of fault arc on-line detecting system based on labwindows/CVI

故障电弧是引起电气火灾的重要原因之一.由于故障电弧的电流不能使继电器保护设备动作,因此当供电线路中发生故障电弧时往往不易被发现和切除,从而引发电气火灾.在实验基础上,设计开发了故障电弧在线检测系统.该系统以AT89S51单片机为下位机,用以检测6路电流信号,并将检测的电流信号通过串行口传送到上位机.上位机以LabWin-dows/CVI为开发平台开发了上位机程序.上位机程序运用多线程技术对供电线路的电流信号进行在线检测和分析,并通过故障电弧检测算法确定是否有故障电弧发生.故障电弧检测算法是通过检测电流信号中是否有周期性奇异点来判断供电线路中是否有故障电弧.实验表明,该系统能有效地对供电线路故障电弧进行实时检测.

Fault arc is one of the main reasons to cause electrical fire. When fault arc occurs in power supply line, the current can not make re＇lay protection equipments act and the fault arc can not be found and excised easily, which brings electrical fire. Based on experiments, a fault arc on - line detecting system is designed. The system uses AT89S51 Single Chip Microcomputer as lower computer, which detects six current signals and sends the signals to the upper computer by serial port. Bases on LabWindows/CVI and uses multithreading technology, the upper computer program to detect and analysis the current signal. With fault arc detecting algorithm, the system can judge whether there has arc or not. The algorithm through detecting periodicity singularity dots to judge the fault arc. The experiments show that the system can detect power supply circuitry fault arc exactly and efficaciously online.