参数变换

A dynamic model was developed with kinematic differential equation derived for a dual-disc over-hung rotor system with rub-impact fault. The stability of the system and stability regions were studied by setting up nonsingular linear transform matrix and by use of Jacobi matrix in combination with the theory of Routh Hurwitz. Then, the effects on the stability regions of the system were discussed with relevant parameters.

建立了悬臂双盘碰摩转子系统的动力学模型和运动微分方程，通过创建该系统的非奇异线性变换矩阵并利用变换矩阵的Jacobi矩阵结合Routh Hurwitz理论，研究了悬臂双盘碰摩转子系统的稳定性和稳定区域，并进行了相应的参数讨论。

Based on the 2 sets of CPI-accuracy plane coordinates composed by the 14 GPS control points along the Hunan-Guangxi railroad line, we carried out coordinate transformation using the Similarity Transformation Method and the Affine Transformation Method in different common point numbers and position distributions.

以湘桂线14个GPS测量点的两套CPI精度的控制点平面坐标为依据，分别用相似变换、仿射变换及不同公共点个数求转换参数进行坐标转换，分析成果精度之间的差异及规律。

The technique made full use of the characteristic of PR controller which can realize zero steady-state error in AC input signal in stationary frame. In the method, the active and reactive current component in the vector control strategy were transformed in the stationary frame to achieve the objective of keeping the DC-link voltage constant, adjusting the power factor and decoupling the active and reactive power. Compared with conventional double close-loop proportional integral controller, the PR technique is better in harmonic compensation without the complex rotating frame transformation and the couple or feedback voltage which is easily influenced by temperature and circuit parameters. The control algorithm is easy to be realized while the robustness and power quality is improved.

该方法充分利用了PR控制器能够在静止坐标系下对交流输入信号无静差控制的优势，将矢量控制策略下的有功电流和无功电流分量转换到静止坐标系下进行调节，实现网侧变换器维持直流电压稳定和调节功率因数的控制任务和双馈电机有功、无功功率的解耦控制，与传统的双闭环PI控制相比，该策略无需繁琐的坐标旋转变换，不存在受温度及电路参数影响的耦合项和前馈补偿项，且易于实现对系统低次谐波电流的补偿，减小了控制算法实现难度，提高了控制系统的鲁棒性和电网电能质量。

The measurement system error model analysis is introduced into power system real time network state analysis as an important part for the first time, which can improve on the state estimation quality and provide the capability to monitor the operation of the measurement system; 2. The theory and algorithm of the on-line estimation and update of measurement noise variance based on the relation between the residual variance and noise variance. The statistic properties of the sample variance are discussed and the relation between the estimation precision and sample size under given confidence level is derived; 3. The theory and algorithm of detection and identification of measurement bias are presented, which is based on the relation between residual mean and noise mean. The statistic properties of sample mean are discussed and the relation between estimation precision and sample size is derived; 4. The Givens orthogonal transformation algorithm is selected to be the essential algorithm of state estimation, the fast orthogonal transformation algorithm with damp factor and the algorithm which can handle the zero injection measurements efficiently are presented; 5. The quantity analysis theory of bad data detectivity and identifibility are presented, which describes the relation between the elements in matrix W〓 and bad data amplitude and can provide the theory base for measurement system design and valuation.

一、首次将量测系统误差模型分析做为一个环节引入电力系统实时网络状态分析中，为EMS系统增加了实时监视系统运行、修正量测系统误差模型的新功能，进一步发挥了实时网络状态分析应用软件的潜力；二、首次提出了应用样本方差在线估计与修正量测系统误差方差的基本理论，讨论了样本方差的统计性质和概率分布，推导出了样本容量、估计精度和置信度之间的关系，给出了在线估计与修正量测系统误差方差的算法；三、首次提出了应用样本均值在线检测与辨识量测偏差的基本理论，讨论了样本均值的统计性质，推导了样本容量、估计精度和置信度之间的基本关系，给出了在线检测与辨识量测偏差的算法；四、在状态估计算法设计中，以Givens变换算法做为基本算法，提出了快速正交变换阻尼因子法和可以有效地处理零注入量测的混合法，并对实时应用中的一些问题进行了讨论；五、提出了不良数据可检测性与可辨识性的定量分析理论，揭示了描述量测系统配置、网络结构与参数的残差灵敏度矩阵中的元素与不良数据的幅值在可检测、可辨识能力上的定量关系，为量测系统配置设计与评价提供了理论基础；六、综合国内外最新研究成果，采用自适应自回归预测技术和稀疏矢量技术，构造了较完善的不良数据检测与辨识算法。

Based on wavelet transform, a new calculation method about character parameter of the restoring force model is also presented.

基于小波变换原理，提出一种新的基于小波变换的恢复力模型特征参数的计算方法。

Firstly, based on the force acting on a single-particle, establish a discriminant formula of the sand threshold, and prove that the sand threshold belongs to the cusp catastrophe. Then establish the basic equation of the cusp catastrophe using coordinate transformation and catastrophe theory. Finally, while particle Reynold number and equivalend diameter are the state variables and Shields parameter is the control variables, we can obtain the model of cusp catastrophe of sand threshold, putting those variables into the basic equations of the cusp catastrophe. The model is derived from the mathematics, which has a certain mathematical theory foundation.

首先从单颗沙粒受力分析出发，建立沙床沙粒起动条件判别公式，进而证明了风沙起动属于尖点型突变；然后通过坐标变换和突变理论建立了尖点突变的基本方程；最后本文选择颗粒雷诺数和等效粒径作为控制变量，希尔兹参数作为状态变量，并把它们代入尖点突变的基本方程，经过拓扑变换得到风沙起动的尖点突变模型，并与前人的公式及实验数据进行比较。

A class of fast-scale bifurcations appearing around the maximum value of the input voltage is discovered for the first time by experiment. Then the influence of the fast-scale bifurcations on the performance of the PFC converters is discussed. Whether the fast-scale bifurcations will appear and how wide the bifurcation region depend on the characteristics of the current loop output. Therefore, the main factors that affect the current loop output are analyzed, including the current loop parameters, inductance, and root-mean-square value of the input voltage.

通过实验，该文首次发现了一类在输入电压最大值附近发生的快时标分岔；详细讨论了快时标分岔对PFC变换器性能的影响；由于电流环输出的特点决定了变换器是否会出现快时标分岔以及分岔区域的大小，该文分析了影响电流环输出的主要因素，包括电流环参数、电感值和输入电压有效值。

Cause and basis for reforming the middle pressure s hi ft saturation column were analyzed,working principle of the new type of vertic al sieve plate column and its reforming situation in the middle pressure shift s aturation column were discussed,analysis and contrast were made for the operat ing parameters and economic benefit before and after reformation.

分析了中压变换饱和塔改造的原因和依据，论述了新型垂直筛板塔的工作原理及其在中压变换饱和塔的应用改造情况，对改造前后运行参数和经济效益进行了分析对比。

Leakage inductance and stray capacitance are two major parasitic components.

反激变换器的高频运行表明功率变压器寄生参数对变换器的性能影响很大。

The Fourier transfermation about the azimuthal angle and Hankeltransfermation about the radial dirction have been used to turn the basic dis-placement equatioons and constitutive equations under cylindrical coordinatesystem into a system of second order ordinary differential equations in thewavenumber domain,by use of the initial prarameter method to solve differ-ential equations.

利用关于方位角的Fourier变换及关于径向的Hankel变换，将柱坐标系下位移基本方程和本构方程转化为波数域内二阶常微分方程组，利用求解微分方程的初参数法，建立了介质层的传递矩阵，导出了层状弹性半空间在地表作用任意静荷载情形下的解析解。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。