电力变压器运行中的声纹信号包含本体的状态信息,可通过部署声纹传感装置对其进行在线监测。为了探究变压器近声场的分布规律、优化声纹监测点的位置,首先采集油箱表面声信号,构成变压器等效声源;然后使用间断伽辽金有限元法(discontinu...电力变压器运行中的声纹信号包含本体的状态信息,可通过部署声纹传感装置对其进行在线监测。为了探究变压器近声场的分布规律、优化声纹监测点的位置,首先采集油箱表面声信号,构成变压器等效声源;然后使用间断伽辽金有限元法(discontinuous Galerkin finite element method,DGFEM)对变压器进行近声场瞬态重构,用于分析声场内声压随时间变化规律;最后构建Pearson均衡相似系数,用于计算备选测点处声纹与等效声源之间的频谱相似度,实现声纹监测位置的定量评估。结果表明,该方法能够评价传感器处于不同位置时对变压器整体声纹状态的感知能力,对变压器声纹在线监测装置部署工作具有一定参考价值。展开更多
In this paper we continue the study of discontinuous Galerkin finite element methods for nonlinear diffusion equations following the direct discontinuous Galerkin （DDG） meth- ods for diffusion problems [17] and the ...In this paper we continue the study of discontinuous Galerkin finite element methods for nonlinear diffusion equations following the direct discontinuous Galerkin （DDG） meth- ods for diffusion problems [17] and the direct discontinuous Galerkin （DDG） methods for diffusion with interface corrections [18]. We introduce a numerical flux for the test func- tion, and obtain a new direct discontinuous Galerkin method with symmetric structure. Second order derivative jump terms are included in the numerical flux formula and explicit guidelines for choosing the numerical flux are given. The constructed scheme has a sym- metric property and an optimal L2 （L2） error estimate is obtained. Numerical examples are carried out to demonstrate the optimal （k ＋ 1）th order of accuracy for the method with pk polynomial approximations for both linear and nonlinear problems, under one-dimensional and two-dimensional settings.展开更多
文摘电力变压器运行中的声纹信号包含本体的状态信息,可通过部署声纹传感装置对其进行在线监测。为了探究变压器近声场的分布规律、优化声纹监测点的位置,首先采集油箱表面声信号,构成变压器等效声源;然后使用间断伽辽金有限元法(discontinuous Galerkin finite element method,DGFEM)对变压器进行近声场瞬态重构,用于分析声场内声压随时间变化规律;最后构建Pearson均衡相似系数,用于计算备选测点处声纹与等效声源之间的频谱相似度,实现声纹监测位置的定量评估。结果表明,该方法能够评价传感器处于不同位置时对变压器整体声纹状态的感知能力,对变压器声纹在线监测装置部署工作具有一定参考价值。
文摘In this paper we continue the study of discontinuous Galerkin finite element methods for nonlinear diffusion equations following the direct discontinuous Galerkin （DDG） meth- ods for diffusion problems [17] and the direct discontinuous Galerkin （DDG） methods for diffusion with interface corrections [18]. We introduce a numerical flux for the test func- tion, and obtain a new direct discontinuous Galerkin method with symmetric structure. Second order derivative jump terms are included in the numerical flux formula and explicit guidelines for choosing the numerical flux are given. The constructed scheme has a sym- metric property and an optimal L2 （L2） error estimate is obtained. Numerical examples are carried out to demonstrate the optimal （k ＋ 1）th order of accuracy for the method with pk polynomial approximations for both linear and nonlinear problems, under one-dimensional and two-dimensional settings.
