The reflection and refraction of traveling wave are quite complicated at the sheath-crossing point of high voltage power cable, due to its remarkably noncontinuous surge impedance.

高压电缆的金属护套交叉互联导致行波在多个波阻抗不连续点产生了复杂的折反射行为，这对高压电缆线路的行波故障测距产生很大的影响。

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Power lines are extremely hostile places for data signals, with high levels of electronic noise and an obstacle course of transformers, surge arrestors and splices that create a huge impedance to the free flow of high-frequency signals.

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