超导磁储能系统(superconducting magnetic energy storage,SMES)是超导应用研究的热点。SMES利用超导磁体的低损耗和快速响应能力,通过电力电子型变流器与电力系统相连,组合为一种既能为其储存电能又能为其释放电能的多功能电磁系统。S...超导磁储能系统(superconducting magnetic energy storage,SMES)是超导应用研究的热点。SMES利用超导磁体的低损耗和快速响应能力,通过电力电子型变流器与电力系统相连,组合为一种既能为其储存电能又能为其释放电能的多功能电磁系统。SMES的先进功能主要体现于,它能大容量超低损耗的储存电能、改善供电质量、提高系统的稳定性和可靠性。该文以SMES的优化设计(IEEE TEAM Workshop Problem 22)为例,介绍了序贯优化方法和克里金(Kriging)统计近似模型在低维和高维、离散域和连续域优化问题中的应用。优化结果显示,该优化方法能在保证设计精度的前提下,极大降低有限元的计算量。如3参数优化问题中有限元的计算量比直接优化的1/10还要少;而8参数优化问题中有限元的计算量约为直接优化的1/3。从而该方法可广泛应用于电磁装置的优化设计问题。展开更多
We study holographic insulator/superconductor phase transition in the framework of Born-Infeld electrodynamics both numerically and analytically. First we numerically study the effects of the Born-Infeld electrodynami...We study holographic insulator/superconductor phase transition in the framework of Born-Infeld electrodynamics both numerically and analytically. First we numerically study the effects of the Born-Infeld electrodynamics on the phase transition, find that when the Born-Infeld parameter increases, the critical chemical potential keeps invariant but the gap frequency becomes larger. Then we employ the variational method for the Sturm-Liouville eigenvalue problem to study the phase transition analytically. The analytical results obtained are found to be consistent with the numerical results.展开更多
文摘超导磁储能系统(superconducting magnetic energy storage,SMES)是超导应用研究的热点。SMES利用超导磁体的低损耗和快速响应能力,通过电力电子型变流器与电力系统相连,组合为一种既能为其储存电能又能为其释放电能的多功能电磁系统。SMES的先进功能主要体现于,它能大容量超低损耗的储存电能、改善供电质量、提高系统的稳定性和可靠性。该文以SMES的优化设计(IEEE TEAM Workshop Problem 22)为例,介绍了序贯优化方法和克里金(Kriging)统计近似模型在低维和高维、离散域和连续域优化问题中的应用。优化结果显示,该优化方法能在保证设计精度的前提下,极大降低有限元的计算量。如3参数优化问题中有限元的计算量比直接优化的1/10还要少;而8参数优化问题中有限元的计算量约为直接优化的1/3。从而该方法可广泛应用于电磁装置的优化设计问题。
文摘We study holographic insulator/superconductor phase transition in the framework of Born-Infeld electrodynamics both numerically and analytically. First we numerically study the effects of the Born-Infeld electrodynamics on the phase transition, find that when the Born-Infeld parameter increases, the critical chemical potential keeps invariant but the gap frequency becomes larger. Then we employ the variational method for the Sturm-Liouville eigenvalue problem to study the phase transition analytically. The analytical results obtained are found to be consistent with the numerical results.
