Based on the layered visco-elastic soil model, according to the Terzaghi's one dimensional consolidation theory, by the method of Laplace transform and matrix transfer technique, the problems about the consolidati...Based on the layered visco-elastic soil model, according to the Terzaghi's one dimensional consolidation theory, by the method of Laplace transform and matrix transfer technique, the problems about the consolidation of layered and saturated visco-elastic soils under arbitrary loading were solved. Through deductions, the general solution, in the terms of layer thickness, the modulus and the coefficients of permeability and Laplacian transform's parameters was obtained. The strain and deformation of the layered and saturated visco-elastic soils under arbitrary loading can be calculated by Laplace inversion. According to the results of several numerical examples, the consolidation of visco-elastic soils logs behind that of elastic soils. The development of effective stress and the displacement is vibrant process under cyclic loading. Finally, an engineering case is studied and the results prove that the methods are very effective.展开更多
One-dimensional ring power system is discredited to a number of nodes each containing a generator with internal reactance and load branch of resistance and reactance with a certain power factor. When a disturbance occ...One-dimensional ring power system is discredited to a number of nodes each containing a generator with internal reactance and load branch of resistance and reactance with a certain power factor. When a disturbance occurs at any machine in the power system, simulative analysis is performed to verify how the variation of load power factor affecting the behavior of electromechanical wave propagation by using the MATLAB package, from which different situations are presented and discussed. These results show the type of load has no effect on the behavior of electromechanical wave propagation.展开更多
考虑静止无功发生器(static var generator,SVG)的非线性和能量耗散特性,基于系统模型的广义Hamilton系统实现,设计非线性控制器。论述了广义Hamilton系统及其实现问题。针对SVG的工作原理建立其非线性动态模型,依据系统模型特性,选取...考虑静止无功发生器(static var generator,SVG)的非线性和能量耗散特性,基于系统模型的广义Hamilton系统实现,设计非线性控制器。论述了广义Hamilton系统及其实现问题。针对SVG的工作原理建立其非线性动态模型,依据系统模型特性,选取适当的结构矩阵和Hamilton函数,完成了系统的广义Hamilton实现。针对SVG模型的广义Hamilton实现,引用L_2干扰抑制控制方法,设计单负荷-无穷大系统中运行的SVG非线性控制器,并利用电力系统分析综合软件(PSASP)对所设计的控制器进行不同负载情况下的仿真,数字仿真结果表明了控制器有较好的补偿效果,并能够维持负载母线电压的稳定。展开更多
This paper presents general semi-analytical solutions to Fredlund and Hasan＇s one-dimensional （1D） consolidation equations for unsaturated soils subject to different initial conditions, homogeneous boundaries and t...This paper presents general semi-analytical solutions to Fredlund and Hasan＇s one-dimensional （1D） consolidation equations for unsaturated soils subject to different initial conditions, homogeneous boundaries and time-dependent loadings. Two variables are introduced to transform the two-coupled governing equations of pore-water and poreair pressures into an equivalent set of partial differential equations （PDEs）, which are solved with the Laplace transform method. The pore-water and pore-air pressures and settlement are obtained in the Laplace transform domMn. The Crump＇s method is used to perform inverse Laplace transform to obtain the solutions in the time domain. The present solutions are more general in practical applications and show good agreement with the previous solutions in the literature.展开更多
文摘Based on the layered visco-elastic soil model, according to the Terzaghi's one dimensional consolidation theory, by the method of Laplace transform and matrix transfer technique, the problems about the consolidation of layered and saturated visco-elastic soils under arbitrary loading were solved. Through deductions, the general solution, in the terms of layer thickness, the modulus and the coefficients of permeability and Laplacian transform's parameters was obtained. The strain and deformation of the layered and saturated visco-elastic soils under arbitrary loading can be calculated by Laplace inversion. According to the results of several numerical examples, the consolidation of visco-elastic soils logs behind that of elastic soils. The development of effective stress and the displacement is vibrant process under cyclic loading. Finally, an engineering case is studied and the results prove that the methods are very effective.
文摘One-dimensional ring power system is discredited to a number of nodes each containing a generator with internal reactance and load branch of resistance and reactance with a certain power factor. When a disturbance occurs at any machine in the power system, simulative analysis is performed to verify how the variation of load power factor affecting the behavior of electromechanical wave propagation by using the MATLAB package, from which different situations are presented and discussed. These results show the type of load has no effect on the behavior of electromechanical wave propagation.
文摘考虑静止无功发生器(static var generator,SVG)的非线性和能量耗散特性,基于系统模型的广义Hamilton系统实现,设计非线性控制器。论述了广义Hamilton系统及其实现问题。针对SVG的工作原理建立其非线性动态模型,依据系统模型特性,选取适当的结构矩阵和Hamilton函数,完成了系统的广义Hamilton实现。针对SVG模型的广义Hamilton实现,引用L_2干扰抑制控制方法,设计单负荷-无穷大系统中运行的SVG非线性控制器,并利用电力系统分析综合软件(PSASP)对所设计的控制器进行不同负载情况下的仿真,数字仿真结果表明了控制器有较好的补偿效果,并能够维持负载母线电压的稳定。
基金Project supported by the National Natural Science Foundation of China(Nos.41372279 and41630633)
文摘This paper presents general semi-analytical solutions to Fredlund and Hasan＇s one-dimensional （1D） consolidation equations for unsaturated soils subject to different initial conditions, homogeneous boundaries and time-dependent loadings. Two variables are introduced to transform the two-coupled governing equations of pore-water and poreair pressures into an equivalent set of partial differential equations （PDEs）, which are solved with the Laplace transform method. The pore-water and pore-air pressures and settlement are obtained in the Laplace transform domMn. The Crump＇s method is used to perform inverse Laplace transform to obtain the solutions in the time domain. The present solutions are more general in practical applications and show good agreement with the previous solutions in the literature.
