摘要
网侧套管是变压器的重要组成部分,在使用过程中因绝缘击穿现象可能引起套管内部冷却油爆炸,给变压器箱体造成很大的安全隐患,因此开展网侧套管爆炸事故的定量评估具有重要意义。通过非线性有限元软件ANSYS/LS-DYNA建立了二维变压器套管模型,采用光滑粒子流体动力学法对变压器套管在内部爆炸作用下的动态响应进行了模拟,分析了不同参数对套管破坏特征的影响规律。通过基于套管径向粒子速度曲线的稳定性判断方法,评估了各套管的失稳时间。结果表明:在内部爆炸作用下,套管管壁中部在内外壁拉压联合作用下率先产生破坏,在冲击波传播过程中套管整体损伤呈凸状变化趋势。过高的爆炸当量、冷却油的存在和初始裂纹缺陷对套管保持稳定有较大影响。爆炸当量的减小可以使套管破坏模式由双向剪切破坏向受拉破坏转变,整体稳定性也随之增强。当爆源位于引线外壁时,冷却油流体所辐射出的冲击波不仅使套管失稳时间有所提前,还会造成外壁膨胀破坏范围变大。应力集中现象和有效壁厚的减小使含初始裂纹缺陷套管剪切破坏失稳现象发展迅速。
The net side bushing is an important part of the transformer.During operation,the cooling oil inside the bushing will explode due to insulation breakdown,which will cause great potential safety hazard to the transformer.Therefore,it is of great significance to carry out quantitative evaluation of the net side bushing explosion accident.In this paper,a two-dimensional transformer bushing model was established by nonlinear finite element software ANSYS/LS-DYNA with smooth particle hydrodynamics(SPH) method.The dynamic response of transformer bushing under internal explosion was simulated.And the influence of different parameters on the failure characteristics of bushing was analyzed.The instability time of bushing was evaluated by the stability judgment method based on the curves of radial particle velocity.The results show that under the action of internal explosion,the middle part of the bushing is first damaged under the combined action of tension and compression of the inner and outer surfaces,and the overall damage of the bushing shows a convex trend during the propagation of the shock wave.The high explosion equivalent,the existence of cooling oil and initial crack defects have a greater influence on the stability of bushing.The decrease of explosion equivalent can change the failure mode of bushing from bidirectional shear failure to tensile failure,and the influence on overall stability is also reduced.When the explosion source is located on the outer wall of the conductive rod,the shock wave radiated by the cooling oil not only makes the bushing instability time advance,but also causes the outer wall expansion damage range to become wider.The stress concentration and the decrease of effective wall thickness make the shear failure instability of bushing with initial crack defects develop rapidly.
作者
赵春风
周志航
朱玉富
ZHAO Chunfeng;ZHOU Zhihang;ZHU Yufu(School of Civil Engineering,Hefei University of Technology,Hefei 230009,Anhui,China)
出处
《高压物理学报》
CAS
CSCD
北大核心
2023年第3期156-167,共12页
Chinese Journal of High Pressure Physics
基金
安徽能源互联网联合基金(2008085UD12)。
关键词
变压器套管
光滑粒子流体动力学法
失稳时间
破坏模式
transformer bushing
smooth particle hydrodynamics method
instability time
failure mode
