晚期HEMP作用下铁路牵引供电系统GIC算法研究

高空核爆电磁脉冲晚期效应（E₃）会引起地磁场剧烈变化并形成地面感应电场。感应电场等效为激励源与地面长距离导体和大地构成回路，产生地磁感应电流 （GIC）。GIC可引起牵引供电系统中变压器直流偏磁，从而严重威胁牵引供电系统的安全运行。本文基于平面波理论、分层大地电导率模型并结合牵引供电系统的电路模型，提出E₃作用下的牵引供电系统GIC算法，并以带回流线的直接供电方式的铁路牵引供电系统为例，首次计算了系统GIC情况。结果表明，该供电方式下牵引供电系统中的GIC远大于系统中变压器等设备的耐受值，为进一步研究E₃作用下牵引供电系统效应及我国铁路设备选型、灾害防治等提供支撑。

Study on GIC algorithm of railway traction power supply system under action of late time HEMP

The late effect of high-altitude electromagnetic pulse (E₃) will cause dramatic changes in the Earth's magnetic field and form a ground induced electric field. The induced electric field is equivalent to forming a loop between the excitation source and the ground long-distance conductor and the Earth, generating a geomagnetic induction current (GIC). GIC can cause DC bias of the transformer in the traction power supply system, thereby seriously threatening the safe operation of the traction power supply system. Based on the plane wave theory, the layered Earth conductivity model and the circuit model of the traction power supply system, this paper proposes the GIC algorithm of the traction power supply system under the action of E₃, and takes the railway traction power supply system with return line direct power supply as an example. Calculating the system GIC situation shows that the GIC in the traction power supply system under this power supply mode is far greater than the withstand value of the transformer and other equipment in the system. The study provides support for further research on the effect of the traction power supply system under the action of E₃, the selection of our domestic railway equipment, and disaster prevention.