title: Numerical Methods for the Analysis of Power Transformer Tank Deformation and Rupture Due to Internal Arcing Faults.
abstract: Power transformer rupture and fire resulting from an arcing fault inside the tank usually leads to significant security risks and serious economic loss. In order to reveal the essence of tank deformation or explosion, this paper presents a 3-D numerical computational tool to simulate the structural dynamic behavior due to overpressure inside transformer tank. To illustrate the effectiveness of the proposed method, a 17.3 MJ and a 6.3 MJ arcing fault were simulated on a real full-scale 360MVA/220kV oil-immersed transformer model, respectively. By employing the finite element method, the transformer internal overpressure distribution, wave propagation and von-Mises stress were solved. The numerical results indicate that the increase of pressure and mechanical stress distribution are non-uniform and the stress tends to concentrate on connecting parts of the tank as the fault time evolves. Given this feature, it becomes possible to reduce the risk of transformer tank rupture through limiting the fault energy and enhancing the mechanical strength of the local stress concentrative areas. The theoretical model and numerical simulation method proposed in this paper can be used as a substitute for risky and costly field tests in fault overpressure analysis and tank mitigation design of transformers.
authors.affiliation: State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Chenguang
authors.initials: C
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Hao
authors.affiliation: Alstom Grid, Redmond, Washington, United States of America.
authors.forename: Song
authors.initials: S
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Baohui
authors.initials: B
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zheng
mesh_terms: D003198:Computer Simulation; D011211:Electric Power Supplies; D020342:Finite Element Analysis; D008962:Models, Theoretical; D011312:Pressure; D012306:Risk; D013314:Stress, Mechanical