Page 116 - 《爆炸与冲击》2026年第11期

第 46 卷 王一鸣，等： 电流互感器泄压装置在燃爆载荷下的动态响应与失效机理 第 11 期

surge may lead to combustion and explosion accidents. Therefore, the rapid-response capability of pressure relief devices under
explosive loading is critical to the operational safety of current transformers. This study focuses on the expander–rupture disc
pressure relief assembly of an LVB-220 current transformer and systematically investigates its dynamic mechanical behavior
and failure mechanism under explosive impact loading. An equivalent hydrogen-air premixed-gas explosion test platform was
constructed. The test system consisted of two stainless-steel flame-acceleration tubes with an inner diameter of 168.3 mm and a
total length of 4 250 mm, a gas-filling and mixing unit, an ignition device, and a high-speed data-acquisition system. A
hydrogen-air mixture with a volume ratio of 27∶75 was used as the combustible gas to reproduce the most severe explosion
conditions caused by arc-generated cracking gas in transformer oil. Pressure and flame signals were recorded synchronously
using a high-temperature pressure transducer and two flame detectors installed along the tube. The tested assembly consisted of
a positive-arch, cross-scored rupture disc made of 316L stainless steel, with a static burst pressure of 0.2 MPa, and a nine-
convolution expander. In addition, an explicit dynamic finite element model was developed using ANSYS/LS-DYNA. The
Johnson-Cook constitutive model was adopted to describe the strain-rate-dependent behavior of 316L stainless steel. The cross-
scored region of the rupture disc was finely meshed with a minimum element size of approximately 0.02 mm to accurately
capture crack initiation and propagation. The measured pressure-time history was applied as the loading boundary condition.
The model was validated by comparing the simulated opening pressure and expander deformation with the experimental
results. The results show that, during the early stage of the explosion, the pressure wave reaches the relief port ahead of the
flame front and triggers the opening of the rupture disc. The measured peak pressure before disc opening is 0.72 MPa, which is
significantly higher than the static calibration value of 0.2 MPa because of strain-rate hardening, structural inertia, and the
spatial nonuniformity of the pressure field under rapid loading. The expander exhibits limited plastic deformation, with the
axial deformation of the nine convolutions ranging from 0.60 to 2.30 mm. The deformation distribution is characterized by
larger values at both ends and smaller values in the middle, reflecting an energy-absorption mechanism dominated by low-
order bending modes. The asymmetric curling of the rupture-disc petals is closely associated with stress-wave reflections and
fluid-structure interaction induced by high-speed venting. The numerical simulation reproduces the crack-growth sequence,
opening morphology, and stress distribution in good agreement with the experimental observations. The proposed integrated
experimental-numerical approach provides a reliable mechanical basis and engineering guidance for optimizing the blast-
resistant design of pressure relief devices for current transformers.
Keywords: current transformer; explosive load; pressure relief device; dynamic response; failure mechanism

电流互感器作为电力系统中承担电流测量与继电保护的重要装备，其长期运行的安全可靠性直接
[1]
影响整个电网的稳定性 。由于设备在服役过程中持续受到电场、热场与力场的耦合作用，再加上局部
绝缘结构缺陷、绝缘油老化和电容屏褶皱等因素的存在，极易在内部形成局部异常强电场，引发绝缘击
穿与油中电弧放电 。电弧作为高温等离子体，会导致绝缘油发生剧烈裂解，生成大量微粒物质和可燃
[2]
气体，造成器身内部压力迅速上升 [3-4] 。在壳体制造工艺或焊接工艺存在薄弱点的情况下，高压油气混合
物可能推动壳体破裂，最终引发爆炸，造成严重设备损毁并可能诱发连锁故障 [5-7] 。
电流互感器爆炸事故具有高度危险性，但对造成事故的动态参数、破坏模式及关键影响机制等缺乏
[8]
系统研究 。特别是在油中电弧放电过程中，高温、高压和强电场耦合作用显著，绝缘油裂解产物的生成
与迁移及其与壳体之间的相互作用复杂多变，使得爆炸行为呈现强瞬态性和空间非均匀性。因此，泄压
[9]
装置能否在燃爆冲击载荷作用下及时开启并保持稳定高效泄放，是维持设备安全的关键 。为防止内部
压力在故障工况下失控，电流互感器通常设计泄压装置——膨胀器，膨胀器承担着吸收和削减冲击能
量、限制爆破片破裂后油气喷射速率、避免泄压口局部结构受损等多重功能 [10] 。膨胀器的波纹节结构能
够在高压脉冲下通过瞬态弯曲与局部屈服吸收能量，其动态响应方式、变形分布及模态特性直接关系到
泄压系统的稳定性与泄放效率。
尽管膨胀器在电力设备中应用广泛，但对其在燃爆载荷下的动态响应及失效机理尚缺乏系统研究，

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