新型AT供电牵引网故障测距方案

Fault Location of Novel AT Power Traction Network

全并联自耦变电器AT(auto transforme)r供电方式在我国高速铁路、客运专线得到了大规模的应用。基于牵引变压器采用次边无中心抽头的单相变压器,在变电所处变压器次边中心不接入钢轨和地。采用广义对称分量法分析短路阻抗特性,绘制AT供电方式下T-R故障的短路阻抗与距离的曲线。证明常用的AT中性点吸上电流比测距原理不能完全适用于该供电方式,并提出了基于AT吸上电流比原理和上下行电流比原理的综合故障测距方案,基于Matlab/Simulink的仿真分析表明,测距原理准确、有效。

The AT （Auto Transformer） power supply mode with parallel connection is applied on high railway and dedicated passenger lines in our country on a large scale. The traction transformer is single phase without neutral termi- nal in secondary side and the mid-point in secondary side is not connected with the rails and earth. Based on the gen- eralized method of symmetrical components, the short-circuit impedance was analyzed. The impedance characteristic curves of T-R fault are plotted. The usual fault location principle based on ratio of AT boosting currents at mid-point is not perfectly adapted to this power supply system. A new fault location comprehensive scheme based on ratio of AT boosting currents and ratio of up-down line currents is put forward. Simulation analysis on Matlab/Simulink indicates that the fault location principle is accurate and effective.