Stabilization of inter-area and/or oscillatory modes in large-scale power system by voltage impedance power system (VIPS) apparatus based on decentralized control scheme

New technologies such as power electronics have made it possible to change continuously the impedance of a power system not only to control power flow but also to enhance stability. A power system incorporating a variable impedance apparatus such as a variable series capacitor (VSrC) and high-speed phase shifter (HSPS) is called VIPS (Variable Impedance Power System) by the authors. This paper proposes a novel control method of VIPS apparatus such as VSrC and HSPS installed at an interconnecting point for stabilizing inter-area unstable and/or oscillatory modes. The proposed design method of the control system is a kind of hierarchical decentralized control method of a large-scale power system based on a Lyapunov function. Under the proposed control scheme, each subsystem can be stabilized independently by local controllers such as AVR, speed governor and PSS, and then the whole interconnected system can be stabilized by VIPS apparatus taking into account interactions between subsystems. The effectiveness and robustness of the VIPS apparatus control are shown by numerical examples with model systems including a large-scale power system.     

热分层流动计算中若干差分格式的比较

本文应用常规的守恒方程及湍流模型，对二维池内热分层流动建立了数学模型，并在Ｐａｔａｎｋａｒ的压力校正法基础上对该数学模型进行了数值计算，计算中的差分格式为乘方格式、一阶迎风、二阶迎风和ＱＵＩＣＫ。通过与实验的比较分析，建议计算应采用ＱＵＩＣＫ格式，并在进行风格独立性试验的基础上使用加密网络。     

COMAS制丝线振动输送机的振动分析

本文根据振动理论对卷烟厂ＣＯＭＡＳ制丝生产线上的振动输送机建立了相应的力学模型及其振动方程。通过对振动方程的求解，分析了该振动输送机的振动特点，并提出了主要参数的选取原则，以期减少基础的振动。     

双稳态孤子

对于具有一定形式非线性的薛定谔方程，存在单孤子解的多稳态，也就是说对于相同能量，单孤子具有不同的传输常数．本文以一非线住形式Ｌｉｎｅａｒ　Ｓｍｏｏｔｈ　Ｓｔｅｐ（ＬＳＳ）函数为例，对孤子的双稳态进行理论分析，并对其双稳态的光学转换进行数值模拟．     

矩形介质波导阵列的一种新型分析方法

本文将等效介电常数近似分析方法在应用范围和处理方法上进行了一些改进．发展为双等效介电常数近似分析法，然后用它来分析矩形介质波导阵列．推得两个一维周期的耦合特征方程。如果将Macatili方法应用范围扩展用来研究该波导阵列也会得到同样的结果，它们都能在二维平面上较准确地反应出通带和阻带等主要周期特性。     

综合应用地震属性、测井数据反演储层参数

本文研究了样点地震属性的特征提取，利用BP神经网络建立测井声波时差和地震属性的非线性映射关系。采用距离加权平均对研究区所有井的反演结果进行外推。为了提高分辨率和计算结果的准确性，详细分析、研究了适合于地震信号分解和重构的小波，以及测井声波时差和地震波阻抗与层界面的关系。最后，对反演的声波时差资料进行界面影响校正，进而计算出较符合实际情况的孔隙率参数。经已知井和新钻井验证，计算结果和实际情况相一致，效果令人满意。     

填料萃取塔液泛速度的计算

介绍了三种有代表性的填料萃取塔的液泛速度计算公式，并通过它们用于三种典型的液-液实验体系和两种不同填料的计算结果的比较，对这些公式的适用范围进行了讨论。     

An equation of state for 1,1-difluroethane (HFC 152a)

An equation of state for 1,1-difluoroethane (HFC 152a, CH₃CHF₂) has been developed on the basis of reliable experimental data including PVT, liquid C_p, and saturated-liquid-density data measured by our group. It is a non-dimensionalized virial equation whose functional form is the same as that originally developed for 1,1,1,2-tetrafluoroethane (HFC 134a) in our group. The effective range is for pressures up to 15 MPa, temperatures from 230 to 450 K, and densities to 1000 kg m⁻³. The equation represents reliable PVT measurements within ± 1% in pressure for the superheated vapour and supercritical fluid, while within ±0.5% in density for the compressed liquid. In addition, it should be noted that the equation represents the other essential thermodynamic properties including vapour pressures, saturated-liquid/ vapour densities, isobaric/isochoric specific heats and sound velocity in both the liquid and gaseous phase of HFC 152a.     

NUMERICAL MODEL FOR DYNAMIC SIMULATION OF TRAFFIC FLOW

ＮＵＭＥＲＩＣＡＬＭＯＤＥＬＦＯＲＤＹＮＡＭＩＣＳＩＭＵＬＡＴＩＯＮＯＦＴＲＡＦＦＩＣＦＬＯＷＷｕＺｈｅｎｇ；ＺｅｎｇＬｉ－ｎｏｎｇ（ＤｅｐａｒｔｍｅｎｔＡｐｐｌｉｅｄＭｅｃｈａｎｉｃｓ，ＦｕｄａｎＵｎｉｖｅｒｓｉｔｙ，Ｓｈａｇｈａｉ２００４３３，Ｐ...