电力及二次电缆屏蔽层接地方式探讨

Discussion on grounding ways of power cable and secondary cable shielding

电力电缆的接地须考虑暂态电压及环流的影响,采用一端或两端接地,以限制暂态过电压和消除环流。二次电缆的接地须考虑暂态过电压和抗电磁干扰,正确理解电缆屏蔽层的作用及屏蔽层正确接地,以提高抗电磁干扰的能力。理论研究和现场试验表明,二次电缆两端接地比一端接地具有更强的抗干扰能力,且过电压水平也较低。采用屏蔽层接地新技术,既有良好的抗干扰效果,又避免了当地电流和干扰过大时烧毁屏蔽层。

By considering the impact of the transient voltage and circulating current,one terminal grounding or two terminals grounding of power and the cable is adopted to limit the transient over-voltage and eliminate circulation.We should consider the transient over-voltage and anti-electromagnetic interference in the grounding of secondary cable,understand the role of the cable shielding correctly and the grounding way properly to improve the ability of anti-electromagnetic interference.Theoretical studies and field tests show that the two terminals grounding method has better anti-interference ability than that of one terminal grounding method,and over-voltage level is low.The new grounding technology of secondary cable shielding has good anti-interference effects,and it also can avoid burning the cable shielding with the large local current and interference.