﻿ 基于ATP-EMTP高压电缆接地线金属护层悬浮电压仿真分析

# 基于ATP-EMTP高压电缆接地线金属护层悬浮电压仿真分析Simulation Analysis the Floating Voltage of Metal Sheath Layer Based on ATP-EMTP for High Voltage Cable Grounding Wire

Abstract: If the grounding system of the transmission cable is damaged, the floating voltage of the sheath layer of power cable will increase, even reaching the extremely high value of danger. High inductive voltage not only endangers workers safety, but also causes insulation layer breakdown, thus re-ducing the carrying capacity of cable, even breaking down the outer sheath insulation, causing cable line operation accident. In order to solve this problem, the electromagnetic transient analysis software ATP-EMTP is used to model and simulate the running transmission cable. By controlling the simulation parameters, the floating voltage of the sheath layer of power cable under different ground wire faults is calculated. The calculation shows that when the direct grounding wire or cross-connected grounding wire of one side of the cable is stolen, the inductive voltage on the metal sheath layer is still below the safe value when the disconnecting point is not too far from the other side of the direct grounding point. When the length of 110 kV cable is about 20 km and the length of 220 kV cable is about 10 km, the inductive voltage amplitude of metal sheath layer will exceed the specified value of national standard. When a piece of metal sheath layer is “suspended”, that is, the direct grounding wire or cross-connected grounding wire on either side of the cable is stolen, the inductive voltage will rise to a very dangerous value, reaching tens of thousands of volts.

1. 引言

Figure 1. Grounding wire stolen picture

2. 仿真模型的建立

2.1. 理论分析与建模方法

Figure 2. 6 km/110 kV high voltage single core cable ATP-EMTP simulation model

2.2. 工频电压源参数设置

(a) (b) (c)

Figure 3. Power frequency voltage source module setting; (a) Voltage source parameters of phase A; (b) Voltage source parameters of phase B; (c) Voltage source parameters of phase C

2.3. 输电电缆参数设置

(a) (b)

Figure 4. Dual cable module setting; (a) Cable simulation basic setting; (b) Configuration and location parameters of each sub-cable

Figure 5. LCC module laying Preview Diagram

2.4. 负载参数设置

3. 金属护套感应电压仿真计算

3.1. 正常情况下金属护套感应电压

Figure 6. Inductive voltage waveform of metal sheath layer under normal condition

3.2. 直接接地线被盗情况下金属护套感应电压

Figure 7. Inductive voltage waveform of metal sheath layer under condition of single side direct grounding wire stolen

3.3. 交叉互联线被盗情况下金属护套感应电压

3.4. 直接与交叉互联线均被盗情况下金属护套感应电压

Figure 8. Inductive voltage waveform of metal sheath layer under condition of single side cross-connected grounding wire stolen

Figure 9. Inductive voltage waveform of metal sheath layer under condition of both side cross-connected grounding wire stolen

1) 当某段金属护套“不悬浮”时

2) 当某段金属护套“悬浮”时

Figure 10. Inductive voltage waveform of metal sheath layer of “non-suspended” cable

3.5. 仿真结果分析

Table 1. Induction voltage amplitude of metal sheath under different steal types

4. 结论

1) 本文针对高压电缆金属护套感应电压进行了理论分析，建立了高压电缆电磁暂态仿真模型，并基于此模型进行了不同接地线被盗情况下的电缆金属护套感应电压计算。

2) 根据所建立的模型与仿真结果可知，当某段电缆仅仅一侧的直接接地线或交叉互联线被盗，在断开点距离另一侧直接接地点长度不是太大时，其金属护套上的感应电压仍在安全值以下。当110 kV电缆长度达到20 km左右，220 kV电缆长度达到10 km左右时，金属护套的感应电压幅值将超过国标规定的300 V。

3) 当某段金属护套“悬浮”时，即该段电缆两侧的直接接地线或交叉互联线均被盗，其感应电压将上升到非常危险的数值，达到数十千伏。一旦出现这种情况，需要立刻对该段电缆接地系统进行紧急修复。

[1] 王尉军, 杨远. 高压电缆金属护套接地系统被盗的危害及对策[J]. 贵州电力技术, 2016, 19(11): 53-56.

[2] 朱双. 接地装置被盗引起的高压电缆故障分析[J]. 黑龙江科技信息, 2016(29): 109.

[3] 丛光, 韩晓鹏, 周作春, 张文新, 李华春, 陈平. 高压单芯电缆接地系统破坏后的悬浮电压分析[J]. 供用电, 2009, 26(5): 61-64.

[4] 刘伟光. 110 kV电缆中间接头故障与交叉互联同轴电缆被盗的分析与对策[J]. 建材与装饰, 2017(38): 208-209.

[5] 陈根, 唐焱, 王新桥. 基于ATP的高压电缆金属护套多点接地故障仿真[J]. 高压电器, 2014(4): 49-53 + 60.

[6] 王亚楠, 丁卫东, 苟杨, 夏健, 闫家启, 王嘉琛, 李志兵. 气体绝缘金属封闭输电线路(GIL)接地问题探讨[J]. 高压电器, 2016(4): 98-102.

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