城际车辆操作断路器对计轴器的电磁干扰研究

Study on Electromagnetic Interference of Intercity Vehicle Operating Circuit Breaker on Axle Counter

为研究城际车辆闭合断路器时引起的操作过电流对计轴器的电磁干扰问题,首先,通过理论分析了过电流产生机理,车辆干扰路径及计轴器的受扰机理;其次,利用等效电路的方法建立某线路的车辆断路器操作过电流干扰源模型与干扰传递模型,并在现车上对变压器初级接地线电流与高压线缆屏蔽层接地电流进行了测试,验证模型的有效性,最终发现过电流在高压线缆这条路径上的分量比变压器接地线上的更大;然后,在电路模型基础上建立钢轨辐射场模型,分析操作过电流的磁场辐射强度,最终发现该线路的钢轨磁场发射值超过了计轴器的受扰阈值。建立的模型可有效地反映城际车辆操作断路器对计轴器的电磁干扰原理与主要干扰路径,为后续进一步研究计轴器的受扰规律与抑制计轴器受扰的方法提供基础。

This paper focuses on the electromagnetic interference of the operating overcurrent caused by the closing of the circuit breaker of intercity vehicles on the axle counter.Firstly,the generation mechanism of overcurrent,vehicle interference path and the interference mechanism of axle counter are analyzed theoretically.Secondly,the interference source model and interference transfer model of operating overcurrent of vehicle circuit breaker of a line are established by using the method of equivalent circuit,and the primary grounding wire current of transformer and the grounding current of shielding layer of high-voltage cable are tested on the existing vehicle to verify the feasibility of the model.Thirdly,the component of overcurrent on the path of high-voltage cable is found greater than that on the grounding wire of transformer.Then,the rail radiation field model is established based on the circuit model,and the magnetic field radiation intensity of operating overcurrent is analyzed.Finally,it is found that the rail magnetic field emission value of the line exceeds the disturbed threshold of axle counter.The model established in this paper can effectively reflect the electromagnetic interference principle and main interference path of urban rail train to axle counter,and provide a solid foundation for further researches on the interference law of axle counter and the method of restraining the interference of axle counter.