Abstract: The poor traction return channel will lead to track circuit power frequency and harmonic interference, track insulation burning, bring harm to the safety of train operation. This paper focus on three typical cases of power frequency interference and insulation burning accident on site, analyzes through centralized monitoring voltage curve fluctuation and dynamic detection of power frequency interference curve, and conducts on-site inspection and testing of abnormal positions. It is found that the unreasonable setting of return channel in the station and the improper connection mode of the section boosting cable will cause the obstruction of traction return channel. Combined with the actual scene and engineering experience, three different solutions for the single line semi-automatic block station, double line sections and EMU operation semi-automatic block section are proposed. The solution can greatly reduce the emergency braking problems caused by excessive power frequency interference, insulation burning and harmonic interference, so as to ensure the safety of train operation.

Key words: power frequency interference, track insulation burning, return channel, safety of train operation

摘要： 牵引回流通道不畅会导致轨道电路工频及其谐波干扰、轨道绝缘烧损，给行车安全带来危害。针对现场3起典型的工频干扰及绝缘烧损事故案列，通过对其集中监测电压曲线波动和动态检测工频干扰曲线进行分析，并对异常位置进行现场检查、测试，发现站内回流通道设置不合理和区间吸上线连接方式不合理会造成牵引回流通道不畅。结合实际场景和工程经验，提出了针对单线半自动闭塞车站、复线区段、动车运行半自动闭塞区间的3种不同场景的解决方案，该方案可极大减少现场工频干扰超标、绝缘烧损及工频谐波干扰导致的紧急制动问题，保障列车运行安全。

关键词: 工频干扰, 绝缘烧损, 回流通道, 列车运行安全