动车组速度信号耦合干扰问题的研究

Study on the Speed Signal Coupling Interference of Multiple Unit

文章主要研究了某型动车组在调试时出现牵引电机速度传感器干扰故障及牵引测试失败问题,故障表现为变流器静态启动测试或动态运行过程中闪报速度传感器故障,严重情况下需切除变流器维持动车组运行。通过对牵引电机速度传感器、变流器屏蔽线缆内部屏蔽接地、变流器速度信号软件处理逻辑等进行排查,确认故障原因为牵引电机速度传感器信号受到系统产生的随机耦合干扰。该故障是多设备在整车接地条件下耦合产生的综合性故障,在故障的排查过程中,采取对变流器内部多处接地进行优化整改。通过逐步实施整改策略,故障发生的概率逐渐减小,最终所有的接地处理优化措施实施后速度信号波形较之前有较大改善,毛刺等干扰信号大幅减少,基本不再报出故障。同时,针对此类接地耦合故障问题,除了对所影响系统进行良好的屏蔽层接地处理措施外,为避免该问题再次发生,采用了优化系统软件滤波方法滤除干扰信号,防止信号失真。

This article mainly studies the speed sensor interference fault and the traction test failure of the traction motor for a certain type of multiple unit during debugging.The fault is manifested in a flashing light alarm reporting the speed sensor fault during the static starting test or the dynamic operation of the converter,and it’s even necessary to cut off the converter to maintain the operation of the multiple unit in a major failure situation.After checking the speed sensor of traction motor,the internal shield earthing of the shield cable of converter,the processing logic of the speed signal software of converter,etc.,it’s confirmed that the fault is caused by random coupling interference generated by the system with the speed sensor signals of traction motor.This fault is a comprehensive fault generated by coupling of multiple devices in the earthing condition of the complete car.During the troubleshooting,multiple earthing points inside the converter are optimized and corrected.After progressive implementation of the corrective strategy,the probability of fault is gradually reduced,and finally after the implementation of all the earthing optimization measures,the signal waveform is greatly improved,the interference signals such as glitches are greatly decreased and almost no fault is reported.Meanwhile,for similar earthing coupling faults,besides the good shielding layer earthing measures taken for the affected system,to avoid the recurrence of the same problem,the optimized filtering method of the system software is used to filter the interference signals so as to prevent the signal distortion.