摘要
提出了用于直流架线电网漏电保护的一种新的基于附加反向直流脉冲的漏电检测方法。其基本原理是采用有别于架线直流工作电源极性的反向直流脉冲测试信号,在电机车上采用二极管构成阻波器,实现漏电电流与机车负荷电流的分离,从而实现漏电电流的检测。控制策略上采用微处理器定时关断三相全控桥,向直流架线提供反向测试电压,并检测架线绝缘电阻值。发现绝缘下降时,停止开通直流工作电源,切断主电路三相接触器,实现漏电保护及报警功能。结果表明该方法具有结构简单,阻波器重量轻、体积小、可靠性高等优点。
A method of leakage current detection is presented for the current-leakage protection of IX; trolley network,which applies the add-in DC test pulse in reverse of working DC voltage. The Node-based signal-block circuit is used in the electric locomotive to separate the leakage current from the load current. The mierocontroller periodically turns off the three-phase full-bridge thyristor rectifier, exerts reverse DC test voltage on the trolley network and tests its insulation resistance. When the resistance is smaller than the setting value, the DC power supply is stopped by tripping off the three-phase AC inputs as the current-leakage protection, and alarm is issued. The proposed method has simple structure with smaller and reliable signal-block circuit.
出处
《电力自动化设备》
EI
CSCD
北大核心
2009年第5期65-68,共4页
Electric Power Automation Equipment
关键词
直流架线
漏电保护
交流信号法
反向直流脉冲
电机车
DC trolley network
current leakage protection
AC signal method
reverse DC pulse
electric locomotive
