高速铁路弓网离线电弧电磁辐射特性的试验研究

高速铁路系统电磁环境十分复杂，其中弓网离线电弧产生的电磁辐射是高速铁路系统最重要的电磁干扰源之一。利用高速弓网关系试验台开展了大电流、高速条件下的弓网离线放电模拟试验，测量了不同牵引电流及不同行车速度下放电辐射场的时域波形，经快速傅里叶变换后得到了离线放电电磁辐射的主要分布频段、分布疏密程度、典型频率值等特征，探讨了放电辐射特性随牵引电流和行车速度的变化规律及原因。研究表明：在大电流、高速条件下，弓网放电电磁辐射能量主要分布于0~100 MHz的频率范围，其中分布最密集频段为45~55 MHz，起弧电磁辐射强度大于熄弧电磁辐射强度；在100~700 A的牵引电流区间内，放电辐射场的幅值随电流增大而增大；相同牵引电流下，频域峰值对应的频率值随车速增大而逐渐变小。该研究结果为弓网电弧电磁辐射干扰的机理研究以及防护提供了试验数据和参考依据。

Experimental study of electromagnetic radiation characteristics of pantograph-catenary off-line arcs in high-speed railway

The electromagnetic environment of the high-speed railway system is very complicated, and the electromagnetic radiation generated by the pantograph-catenary off-line arcs is one of the most important sources of electromagnetic interference in the high-speed railway system. The high-speed pantograph-catenary relationship experimental bench is used for the simulation experiment of pantograph-catenary off-line discharge under the condition of high current and high speed. The time-domain waveforms of discharge radiation field under different arc currents and vehicle speeds are both measured, and the characteristics of off-line discharge electromagnetic radiation, including the main frequency band, distribution density and typical frequency values, are obtained after applying FFT(Fast Fourier Transform). The variation laws and causes of discharge radiation characteristics along with traction current and driving speed are carried out. The study results show that, under the condition of high current and high speed, the electromagnetic radiation energy of pantograph-catenary discharge is mainly distributed in the frequency range of 0~100 MHz, of which the most densely distributed frequency band is 45~55 MHz, and the electromagnetic radiation intensity of arc initiation is greater than that of arc extinction. In the traction current range of 100~700 A, the amplitude of the discharge radiation field increases with the increase of the traction current. Under the same traction current, the frequency value corresponding to the frequency-domain peak value gradually decreases with the increase of the driving speed. The study results provide experimental data and reference basis for the mechanism research and protection of the electromagnetic radiation interference caused by the pantograph-catenary arc.