提出一种三维瞬态场路耦合有限元分析方法计算变压器结构件的三维漏磁场及损耗,该方法能够考虑铁磁材料非线性各向异性的电磁特性。以TEAM Problem 21C-M1模型为例,通过磁屏蔽和导磁钢板涡流损耗的计算,表明计算结果和测量结果基本吻合...提出一种三维瞬态场路耦合有限元分析方法计算变压器结构件的三维漏磁场及损耗,该方法能够考虑铁磁材料非线性各向异性的电磁特性。以TEAM Problem 21C-M1模型为例,通过磁屏蔽和导磁钢板涡流损耗的计算,表明计算结果和测量结果基本吻合,验证了该方法的正确性。并将该方法应用于一台大型单相自耦电力变压器的数值计算中,结构件损耗的计算误差为3.64%。验证了本文提出方法的正确性和可行性,使得大型电力变压器三维漏磁场及结构件损耗的准确计算得以实现。展开更多
针对大型电力变压器箱体屏蔽与降低箱壳涡流损耗问题,利用三维瞬态有限元法,在考虑箱体材料的非线性和磁屏蔽叠片结构的情况下,计算分析了不同屏蔽方式的屏蔽特性,对磁屏蔽叠片结构采用各向异性材料来近似表示叠片特性。以一台330 k V...针对大型电力变压器箱体屏蔽与降低箱壳涡流损耗问题,利用三维瞬态有限元法,在考虑箱体材料的非线性和磁屏蔽叠片结构的情况下,计算分析了不同屏蔽方式的屏蔽特性,对磁屏蔽叠片结构采用各向异性材料来近似表示叠片特性。以一台330 k V单相电力变压器为研究对象进行计算分析,分别计算研究了配置箱体前后侧磁屏蔽、增加上下磁屏蔽和增添箱体拐角铜屏蔽三种方案下箱体的磁场及涡流损耗。基于计算结果,总结了不同屏蔽方式的屏蔽特性,为工程设计提供了依据。展开更多
We calculate the multicomponent responses of surface-hole transient electromagnetic method. The methods and models are unsuitable as geoelectric models of conductive surrounding rocks because they are based on regular...We calculate the multicomponent responses of surface-hole transient electromagnetic method. The methods and models are unsuitable as geoelectric models of conductive surrounding rocks because they are based on regular local targets. We also propose a calculation and analysis scheme based on numerical simulations of the subsurface transient electromagnetic fields. In the modeling of the electromagnetic fields, the forward modeling simulations are performed by using the finite-difference time-domain method and the discrete image method, which combines the Gaver–Stehfest inverse Laplace transform with the Prony method to solve the initial electromagnetic fields. The precision in the iterative computations is ensured by using the transmission boundary conditions. For the response analysis, we customize geoelectric models consisting of near-borehole targets and conductive wall rocks and implement forward modeling simulations. The observed electric fields are converted into induced electromotive force responses using multicomponent observation devices. By comparing the transient electric fields and multicomponent responses under different conditions, we suggest that the multicomponent-induced electromotive force responses are related to the horizontal and vertical gradient variations of the transient electric field at different times. The characteristics of the response are determined by the varying the subsurface transient electromagnetic fields, i.e., diffusion, attenuation and distortion, under different conditions as well as the electromagnetic fields at the observation positions. The calculation and analysis scheme of the response consider the surrounding rocks and the anomalous field of the local targets. It therefore can account for the geological data better than conventional transient field response analysis of local targets.展开更多
文摘提出一种三维瞬态场路耦合有限元分析方法计算变压器结构件的三维漏磁场及损耗,该方法能够考虑铁磁材料非线性各向异性的电磁特性。以TEAM Problem 21C-M1模型为例,通过磁屏蔽和导磁钢板涡流损耗的计算,表明计算结果和测量结果基本吻合,验证了该方法的正确性。并将该方法应用于一台大型单相自耦电力变压器的数值计算中,结构件损耗的计算误差为3.64%。验证了本文提出方法的正确性和可行性,使得大型电力变压器三维漏磁场及结构件损耗的准确计算得以实现。
文摘针对大型电力变压器箱体屏蔽与降低箱壳涡流损耗问题,利用三维瞬态有限元法,在考虑箱体材料的非线性和磁屏蔽叠片结构的情况下,计算分析了不同屏蔽方式的屏蔽特性,对磁屏蔽叠片结构采用各向异性材料来近似表示叠片特性。以一台330 k V单相电力变压器为研究对象进行计算分析,分别计算研究了配置箱体前后侧磁屏蔽、增加上下磁屏蔽和增添箱体拐角铜屏蔽三种方案下箱体的磁场及涡流损耗。基于计算结果,总结了不同屏蔽方式的屏蔽特性,为工程设计提供了依据。
基金supported by the Young Scientists Fund of the National Natural Science Foundation of China(No.41304082)the China Postdoctoral Science Foundation(No.2016M590731)+2 种基金the Young Scientists Fund of the Natural Science Foundation of Hebei Province(No.D2014403011)the Program for Young Excellent Talents of Higher Education Institutions of Hebei Province(No.BJ2016046)the Geological survey project of China Geological Survey(No.1212011121197)
文摘We calculate the multicomponent responses of surface-hole transient electromagnetic method. The methods and models are unsuitable as geoelectric models of conductive surrounding rocks because they are based on regular local targets. We also propose a calculation and analysis scheme based on numerical simulations of the subsurface transient electromagnetic fields. In the modeling of the electromagnetic fields, the forward modeling simulations are performed by using the finite-difference time-domain method and the discrete image method, which combines the Gaver–Stehfest inverse Laplace transform with the Prony method to solve the initial electromagnetic fields. The precision in the iterative computations is ensured by using the transmission boundary conditions. For the response analysis, we customize geoelectric models consisting of near-borehole targets and conductive wall rocks and implement forward modeling simulations. The observed electric fields are converted into induced electromotive force responses using multicomponent observation devices. By comparing the transient electric fields and multicomponent responses under different conditions, we suggest that the multicomponent-induced electromotive force responses are related to the horizontal and vertical gradient variations of the transient electric field at different times. The characteristics of the response are determined by the varying the subsurface transient electromagnetic fields, i.e., diffusion, attenuation and distortion, under different conditions as well as the electromagnetic fields at the observation positions. The calculation and analysis scheme of the response consider the surrounding rocks and the anomalous field of the local targets. It therefore can account for the geological data better than conventional transient field response analysis of local targets.
