直流牵引系统馈线微机保护装置

直流牵引系统馈线远端非金属性小短路电流故障是直流牵引系统馈线保护的难点。文中阐述了电流变化量保护原理，分析了牵引馈线远端经电阻短路和电弧短路故障电流的变化特征；提出采用电流变化率为启动元件电流增量检测的主保护判据，并针对电弧故障电流变化特征提出电流增量辅助保护判据，两者相结合实现直流牵引系统馈线保护方案；详细分析了不同情况下保护判据的动作特性及整定原则；以该保护方案为基础研制开发了馈线微机保护装置，并通过了保护测试与现场试验。

Research and Development of Microcomputer-based Feeder Protection for DC Traction Power Supply System

It is becoming more difficult to detect the remote short circuit faults of DC traction power supply grid, particularly high impedance faults and arcing faults. The principles based on transient current fluctuation are discussed in detail in this paper, and the transient characteristics of fault currents are investigated when the faults happen through high impedance and arc. A new integrated protection scheme based on rate of rise of current and current increment is proposed. It is shown that the main protection principle based on rate of rise of current is credible for non-arcing faults. It is also shown that the aid principle based on current increment is sensitive to the arcing faults. The microcomputer-based feeder protection device based on the proposed protection scheme is developed and passes the experiment on spot. The results show that the protection device can reliably and sensitively detect short circuit faults.