提出一种描述超/特高压磁控式并联电抗器(magnetically controlled shunt reactor,MCSR)非线性磁饱和特性的实用化解耦电磁暂态模型。基于动态磁阻的思想,提出瞬时等效电抗的算法,反映了交直流混合励磁条件下饱和等效电抗的实时动态变...提出一种描述超/特高压磁控式并联电抗器(magnetically controlled shunt reactor,MCSR)非线性磁饱和特性的实用化解耦电磁暂态模型。基于动态磁阻的思想,提出瞬时等效电抗的算法,反映了交直流混合励磁条件下饱和等效电抗的实时动态变化特性;以反双曲函数描述非线性磁路特性,对耦合磁路方程进行解耦,并用带阻尼的隐式梯形积分算法对瞬时等效电抗进行差分化,建立电磁暂态模型,能够与电磁暂态计算相兼容。已在电力系统全数字实时仿真装置(advanced digital power system simulator,ADPSS)中编程实现了仿真模型的工程化应用,并搭建标准算例,以工程投运的MCSR现场运行参数为模型输入量,进行仿真,计算结果数值精确,波形吻合,验证了模型的正确性。展开更多
提出一种磁控式并联电抗器(magnetically controlled shunt reactor,MCSR)的非线性自适应逆控制系统的建模算法,采用"分解建模"的设计思想,将元件建模和动态系统辨识理论相结合,对MCSR的非线性元件部分和外在系统的动态影响...提出一种磁控式并联电抗器(magnetically controlled shunt reactor,MCSR)的非线性自适应逆控制系统的建模算法,采用"分解建模"的设计思想,将元件建模和动态系统辨识理论相结合,对MCSR的非线性元件部分和外在系统的动态影响分别建模。建立描述非线性磁路特性的逆对象方程,根据"阿贝尔定理"对非线性方程进行泰勒展开,以解析解形式求出控制系统需要的励磁电流,建立逆对象传递函数;针对外在电力系统与MCSR的相关性,建立时变参数的动态回归方程,以最小二乘法求出时变参数。已在电力系统全数字实时仿真装置(advanced digital power systemsimulator,ADPSS)中编程实现了控制模块的工程化应用,并以MCSR实际运行参数搭建算例,验证了控制系统的有效性和实用性。展开更多
In this study consecutive consolidated isotropically drained triaxial tests for the coefficient of earth pressure at rest(K_0) were carried out to investigate its rules of evolution as well as its strength characteris...In this study consecutive consolidated isotropically drained triaxial tests for the coefficient of earth pressure at rest(K_0) were carried out to investigate its rules of evolution as well as its strength characteristics for normal,consolidated saturated silt under high pressure.The tests results indicate that:1) for normal,consolidated saturated silt,K_0 values increase as the consolidation stress increases at high pressure levels,while the nonlinear characteristics of K_0 are inconspicuous compared to cohesive soils;2) the Jaky and Roscoe equations,used to calculate K_0,are only suitable for certain soils,but cannot represent these values for normal, consolidated saturated silt due to the variation in bilinear strength at high pressure;and 3) there are close relations between the nonlinear characteristics of K_0 and the void ratio,measured in the tests.Both share the same functional form while under pressure. Based on our experimental results,we developed an empirical linear model to interpret the rules of nonlinear variation for the coefficient of earth pressure at rest.展开更多
文摘提出一种描述超/特高压磁控式并联电抗器(magnetically controlled shunt reactor,MCSR)非线性磁饱和特性的实用化解耦电磁暂态模型。基于动态磁阻的思想,提出瞬时等效电抗的算法,反映了交直流混合励磁条件下饱和等效电抗的实时动态变化特性;以反双曲函数描述非线性磁路特性,对耦合磁路方程进行解耦,并用带阻尼的隐式梯形积分算法对瞬时等效电抗进行差分化,建立电磁暂态模型,能够与电磁暂态计算相兼容。已在电力系统全数字实时仿真装置(advanced digital power system simulator,ADPSS)中编程实现了仿真模型的工程化应用,并搭建标准算例,以工程投运的MCSR现场运行参数为模型输入量,进行仿真,计算结果数值精确,波形吻合,验证了模型的正确性。
文摘提出一种磁控式并联电抗器(magnetically controlled shunt reactor,MCSR)的非线性自适应逆控制系统的建模算法,采用"分解建模"的设计思想,将元件建模和动态系统辨识理论相结合,对MCSR的非线性元件部分和外在系统的动态影响分别建模。建立描述非线性磁路特性的逆对象方程,根据"阿贝尔定理"对非线性方程进行泰勒展开,以解析解形式求出控制系统需要的励磁电流,建立逆对象传递函数;针对外在电力系统与MCSR的相关性,建立时变参数的动态回归方程,以最小二乘法求出时变参数。已在电力系统全数字实时仿真装置(advanced digital power systemsimulator,ADPSS)中编程实现了控制模块的工程化应用,并以MCSR实际运行参数搭建算例,验证了控制系统的有效性和实用性。
基金Financial support for this work,provided by the National Natural Science Foundation of China (No.50534040)the Project of the Science and Technology Ministry of China(No.2006BAB16B01)the Post Graduate Research Project of Jiangsu Province (No.CX08B_103Z),
文摘In this study consecutive consolidated isotropically drained triaxial tests for the coefficient of earth pressure at rest(K_0) were carried out to investigate its rules of evolution as well as its strength characteristics for normal,consolidated saturated silt under high pressure.The tests results indicate that:1) for normal,consolidated saturated silt,K_0 values increase as the consolidation stress increases at high pressure levels,while the nonlinear characteristics of K_0 are inconspicuous compared to cohesive soils;2) the Jaky and Roscoe equations,used to calculate K_0,are only suitable for certain soils,but cannot represent these values for normal, consolidated saturated silt due to the variation in bilinear strength at high pressure;and 3) there are close relations between the nonlinear characteristics of K_0 and the void ratio,measured in the tests.Both share the same functional form while under pressure. Based on our experimental results,we developed an empirical linear model to interpret the rules of nonlinear variation for the coefficient of earth pressure at rest.
