高速动车组永磁牵引系统接地检测方法研究

Research on grounding detection method for permanent magnet traction system in high-speed EMUs

为了更好地提高高速动车组永磁牵引系统接地故障诊断的准确性,文章提出了一种适用于永磁牵引系统的接地检测新方法。通过结合接地检测电路的拓扑结构,分析了不同接地情况下接地电压的特点,并在此基础上提出了优化接地电压超限判定算法、采用各轴逆变器分步检测和增加永磁接触器诊断节点等措施,通过该方法可以准确诊断出电机侧、变压器侧和变流器侧具体的接地点,提高了故障点定位的准确性。半实物仿真和地面机组试验结果验证了该方法的可行性。

To improve the accuracy of grounding fault diagnosis in the permanent magnet traction system of high-speed EMUs,this paper proposed a new grounding detection method suitable for permanent magnet traction systems.By combining the topology structure of the grounding detection circuit,the characteristics of grounding voltage under different grounding conditions were analyzed.Based on this analysis,measures such as optimizing the decision algorithm for grounding voltage exceeding limits,adopting step-by-step detection of each axis inverter,and adding diagnostic nodes for permanent magnet contactors were proposed.This method can accurately diagnose the specific grounding points on the motor side,transformer side and inverter side,thereby improving the accuracy of fault point localization.The feasibility of this method was verified by hardware-in-the-loop simulation and ground unit test results.