动车组牵引电机轴承超温故障原因分析及优化措施研究

Analysis and Optimization Measures for Overtemperature Fault of EMU Traction Motor Bearings

针对某平台动车组牵引电机频繁出现轴承超温报警故障问题,展开轴承超温故障原因分析。根据润滑脂过温劣化和轴承电腐蚀两类故障特征现象,判定轴承超温由轴间功率分配不平衡、轴电压过大和轴承绝缘抗击穿能力低导致。研究各轴电机功率分配差异、动车组接地方式、轴承绝缘涂层厚度等影响因素,明确轴承超温故障产生原因及机理。结果表明,车控驱动的动车出现轮轴滑行或空转时,会导致其他轴电机过载升温加速润滑脂老化;由分合闸过电压产生的牵引电机轴电压与接地位置和回路参数相关,不同位置接地方案下轴电压的差异最高可达到两倍;在较高轴电压下,轴承绝缘涂层厚度不足会导致绝缘击穿,造成轴电流对轴承的损伤,最终导致轴承异常磨损超温。为防止轴承超温故障频繁出现,提出TCU控制逻辑优化、整车接地方式优化及绝缘涂层厚度优化等措施,为列车安全运行提供有效的优化方案。

In view of the frequent occurrence of bearing overtemperature alarm faults of the traction motor of an electrical multiple unit(EMU)platform,an analysis was conducted on the causes of bearing overtemperature faults.According to the two types of fault characteristics of grease overtemperature deterioration and bearing electrical corrosion,the fault causes of unbalanced power distribution,excessive bearing voltage and low insulation capacity were determined.Based on the study of the influencing factors such as the motor power difference,the EMU grounding mode and the thickness of bearing insulation coating,the causes and mechanisms of bearing overtemperature faults were clarified.The results indicate that the slipping or spinning of some wheels of a train driven by vehicle control will cause overloading,heating up,and accelerated grease aging of other motors.The shaft voltage of the traction motor generated by the switching overvoltage is related to the grounding position and loop parameters,and the difference in shaft voltage can be up to twice under the different grounding schemes at different positions.Under high shaft voltage,insufficient thickness of bearing insulation coating will lead to insulation breakdown,causing damage to the bearing by shaft current,until eventual abnormal wear and overheating of bearings.The corresponding solutions for optimizing control logic,train grounding methods,and insulation coating thickness were proposed,providing optimization solutions for safe train operation.