摘要
高压单芯电缆往往采用金属护套单端接地或金属护套交叉换位互联接地。当电缆受到过电压入侵时,金属护套上的过电压可能超过外护层的绝缘水平,击穿外护层。高压电缆单芯金属护套雷电过电压的仿真计算,与仿真所用模型、元件参数以及电缆的接线方式、运行方式等有关,而元件模型、参数的准确获得是非常困难的,电缆运行方式也是多种多样的。为此,在典型状况下护套雷电过电压仿真计算的基础上,对包括电缆结构、大地电阻率、侵入波波形、冲击接地电阻、电缆长度、负荷电阻的大小及性质等、模型及参数对护套雷电过电压的影响进行了分析研究,并研究了两个或更多的交叉互联大段串联以及有多回电缆出线时,电缆护套上的过电压。研究表明,电缆的结构、电缆长度、入波波形以及负荷电阻的大小和性质对金属护套过电压有较大的影响;当雷电入侵多个交叉互联大段串联的电缆导体时,应在各绝缘接头处加护层保护器;并联出线越多,其护套上的过电压越低。
Sheathes of high voltage single-core cable are usually grounded at one terminal （without applied crossbonding） or two terminals grounded （with applied cross bonding）. When lightning invade into cable core, the over- voltage induced in its sheaths may exceed its insulation lever, which break down the sheath in the weak spot. The over-vohage inducted in cable sheath is affected by the simulation models, which is hard to be exact and precise. Based on the simulation of sheath lightning over voltage （SLOV） of typical connection of single-core cables, the effects of several factors on SLOV, such as the cable structure and its length, the grounding resistance, stricken wave shape, impactive grounding resistance, and magnitude and character of loads, are discussed in this paper. The SLOVs of 2 cable segments with applied cross bonding in series and that of several cable segments in parallel are also simulated here. Simulation and discussion indicate that cable structure and its length, stricken wave shape, and magnitude and character of cable loads, have more influence to SLOV. When lightning invaded into cable-core of several cross-bonding segments in series, the arrestors should be installed in every connection. And the more the number of cable segments in parallel, the lower the SLOV.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2009年第4期784-789,共6页
High Voltage Engineering
