当电力系统遭受某种较大扰动时,其安全稳定将受到威胁。为实现对整个系统受扰后机电暂态过程的完整跟踪,提出一种新的融合同步发电机动态状态估计(dynamic state estimation of synchronous generator,DSE-SG)的电力系统状态估计(state ...当电力系统遭受某种较大扰动时,其安全稳定将受到威胁。为实现对整个系统受扰后机电暂态过程的完整跟踪,提出一种新的融合同步发电机动态状态估计(dynamic state estimation of synchronous generator,DSE-SG)的电力系统状态估计(state estimation of power system,SE-PS),研究该如何将DSE-SG的结果进一步应用于系统侧SE-PS中去,以实现全系统动、静态状态量的统一估计。首先,围绕全电力系统机电暂态DSE的求解方式,论述了完全联立的不可行性、解耦估计的实现条件以及复耦估计的必要性与意义;其次,在梳理DSE-SG与SE-PS概念、数学模型的基础上,厘清了所涉变量、方程组的地位、作用、关系及数据流程,为复耦媒介量的选取及接口方式的确定奠定了理论基础,形成了复耦估计的实现构思;进一步,提出两种不同的接口方式,详细给出其各自具体的实现方法及流程;最后,将所提方法在IEEE9节点系统中予以实现,结果表明该方法可良好跟踪全电力系统机电暂态过程,实现动、静态状态量的统一估计,较未融合DSE-SG结果的传统SE-PS精度更高,滤波效果更显著。展开更多
A motor-driven linkage system with links fabricated from 3-dimensional braided composite materials was studied. A group of coupling dynamic equations of the system, including composite materials parameters, electromag...A motor-driven linkage system with links fabricated from 3-dimensional braided composite materials was studied. A group of coupling dynamic equations of the system, including composite materials parameters, electromagnetism parameters of the motor and structural parameters of the link mechanism, were established by finite element method. Based on the air-gap field of non-uniform airspace of three-phase alternating current motor caused by the vibration eccentricity of rotor, the relation of electromechanical coupling at the actual running state was analyzed. And the motor element, which defines the transverse vibration and torsional vibration of the motor as its nodal displacement, was established. Then, based on the damping element model and the expression of energy dissipation of the 3-dimentional braided composite materials, the damping matrix of the system was established by calculating each order modal damping of the mechanism.展开更多
The effect of T6I6 treatment on the dynamic mechanical and microstructure behaviour of Al-Si-Mg-Cu cast alloy was investigated using split Hopkinson pressure bar(SHPB), transmission electron microscopy(TEM), and highr...The effect of T6I6 treatment on the dynamic mechanical and microstructure behaviour of Al-Si-Mg-Cu cast alloy was investigated using split Hopkinson pressure bar(SHPB), transmission electron microscopy(TEM), and highresolution transmission electron microscopy(HRTEM). Besides, the impact resistances of T6I6 and T6 motor shells of new energy vehicles made of Al-Si-Mg-Cu cast alloy were compared using a trolley crash test. The results indicated that the main strengthening-phases of the T6 peak-aged and T6I6 peak-aged alloy were GP zone and β″ precipitates. T6I6treatment can increase the density and size of β″ precipitates in peak-aged alloy and enhance both its tensile strength(σb)and elongation(δ). The dynamic toughness values of T6I6 samples are 50.34 MJ/m^(3) at 2000 s^(-1) and 177.34 MJ/m^(3) at 5000 s^(-1) which are 20% and 12% higher than those of T6 samples, respectively. Compared with a T6 shell, the overall deformation of T6I6 shell is more uniform during the crash test. At an impact momentum of 3.5×10;kg·m/s, the T6I6shell breaks down at 0.38 s which is 0.10 s later than the T6 shell.展开更多
文摘当电力系统遭受某种较大扰动时,其安全稳定将受到威胁。为实现对整个系统受扰后机电暂态过程的完整跟踪,提出一种新的融合同步发电机动态状态估计(dynamic state estimation of synchronous generator,DSE-SG)的电力系统状态估计(state estimation of power system,SE-PS),研究该如何将DSE-SG的结果进一步应用于系统侧SE-PS中去,以实现全系统动、静态状态量的统一估计。首先,围绕全电力系统机电暂态DSE的求解方式,论述了完全联立的不可行性、解耦估计的实现条件以及复耦估计的必要性与意义;其次,在梳理DSE-SG与SE-PS概念、数学模型的基础上,厘清了所涉变量、方程组的地位、作用、关系及数据流程,为复耦媒介量的选取及接口方式的确定奠定了理论基础,形成了复耦估计的实现构思;进一步,提出两种不同的接口方式,详细给出其各自具体的实现方法及流程;最后,将所提方法在IEEE9节点系统中予以实现,结果表明该方法可良好跟踪全电力系统机电暂态过程,实现动、静态状态量的统一估计,较未融合DSE-SG结果的传统SE-PS精度更高,滤波效果更显著。
基金Project(50175031) supported by the National Natural Science Foundation of China
文摘A motor-driven linkage system with links fabricated from 3-dimensional braided composite materials was studied. A group of coupling dynamic equations of the system, including composite materials parameters, electromagnetism parameters of the motor and structural parameters of the link mechanism, were established by finite element method. Based on the air-gap field of non-uniform airspace of three-phase alternating current motor caused by the vibration eccentricity of rotor, the relation of electromechanical coupling at the actual running state was analyzed. And the motor element, which defines the transverse vibration and torsional vibration of the motor as its nodal displacement, was established. Then, based on the damping element model and the expression of energy dissipation of the 3-dimentional braided composite materials, the damping matrix of the system was established by calculating each order modal damping of the mechanism.
基金Projects(52075166, 51875197) supported by the National Natural Science Foundation of ChinaProjects(2019RS2064,2019GK5043) supported by the Science and Technology Planning Project of Hunan Province,China。
文摘The effect of T6I6 treatment on the dynamic mechanical and microstructure behaviour of Al-Si-Mg-Cu cast alloy was investigated using split Hopkinson pressure bar(SHPB), transmission electron microscopy(TEM), and highresolution transmission electron microscopy(HRTEM). Besides, the impact resistances of T6I6 and T6 motor shells of new energy vehicles made of Al-Si-Mg-Cu cast alloy were compared using a trolley crash test. The results indicated that the main strengthening-phases of the T6 peak-aged and T6I6 peak-aged alloy were GP zone and β″ precipitates. T6I6treatment can increase the density and size of β″ precipitates in peak-aged alloy and enhance both its tensile strength(σb)and elongation(δ). The dynamic toughness values of T6I6 samples are 50.34 MJ/m^(3) at 2000 s^(-1) and 177.34 MJ/m^(3) at 5000 s^(-1) which are 20% and 12% higher than those of T6 samples, respectively. Compared with a T6 shell, the overall deformation of T6I6 shell is more uniform during the crash test. At an impact momentum of 3.5×10;kg·m/s, the T6I6shell breaks down at 0.38 s which is 0.10 s later than the T6 shell.
