动车组高压线缆屏蔽层接地分析

Analysis of Shielding Layer Grounding of EMU High-voltage Cables

高压屏蔽电缆在动车组电气系统的运行过程中会产生感应电压,需要通过屏蔽层的合理接地来保证车辆运用安全和减少线缆对外电磁辐射。介绍了动车组的接地系统,以变压器次边绕组电缆为例,从屏蔽层感应电压的产生机理出发,分析了高压线缆屏蔽层单端接地的原理,提出了线缆屏蔽层的接地结构,并通过试验对比了屏蔽层在可靠接地和接地不良条件下的感应电压值,验证了接地结构的可靠性。

High-voltage shielded cables generate induced voltage during EMU electrical system operation.The shielding layer needs to be properly grounded to ensure vehicle safety and reduce external electromagnetic radiation from cables.Taking the transformer secondary winding cable as an example,the EMU grounding system is introduced.Starting from the mechanism of induced voltage on the shielding layer,the principle of single-ended grounding of high-voltage cables shielding layer is analyzed,and the grounding structure of the cable shielding layer is proposed.Induced voltage value of the shielding layer under reliable grounding and poor grounding conditions is compared through experiments,which verifies the reliability of the grounding structure.