微间隙形状对电缆中间接头场强分布影响性研究

Influence of Micro-Gap Shape on Cable Middle Joint Field Strength Distribution

因近年来由电缆中间接头造成的电缆绝缘击穿、电缆爆炸的现象屡见不鲜,其中主要原因是局部场强畸变而引起的局部放电,而局部微间隙的存在是造成场强过于集中的主要因素之一,因此针对电缆中间接头存在不同形状的局部微间隙进行场强分析是有意义的。通过对含有局部微间隙的电缆中间接头进行有限元分析求解,结果表明微间隙存在,会使内部场强发生严重畸变,且场强的畸变程序与微间隙的面积成正比关系;微间隙的面积相同、形状不同时,对应的场强数值是不同的,圆斑状间隙比较于其它间隙形状时,内部场强数值最小,但应力锥处场强最大;而正方形状间隙,内部场强数值取到最大值。直接表明局部微间隙形状对场强分布是有显著影响的。

In recent years, the cable insulation breakdown and cable explosions caused by intermediate cable connector are common occurrences, which is mainly due to the partial discharge for the local field strength dis- tortion, ＂and the presence of local micro-gap is mainly responsible for the field strength too focused. The field strength analysis of different shapes of local micro-gap is meaningful. The intermediate cable containing local micro-gap joint is studied by finite element analysis software. The results showed that： 1. a micro gap can make a serious distortion of the internal field, and the field strength is proportional to the area of distortion; 2. with the same micro-gap area and different shape, the corresponding field strength values are different; compared to the other shapes of the gap, the internal field strength value of a round gap is the smallest, but its field strength is strongest at stress cone; the internal field strength of a square-shaped gap can have the maximum value. It is concluded that the different shapes of gaps have a significant influence on field strength distribution.