暂态

By using this method, the angular frequency, amplitude, initial phase angle, decay constant of each component in transient voltage and/or current waveforms can be precisely extracted. Also, all other kinds of transient procedure can be analyzed by this method. Thirdly, a new definition of generalized instantaneous reactive power and generalized instantaneous reactive current in dq0 coordinates under any nonsinusoidal and unbalanced three-phase circuit is proposed for the first time. The detection and compensation method for different instantaneous reactive currents are also concerned.

本文首先提出了用于快速高精度频谱分析的一种改进快速傅立叶变换方法，该法具有速度快、精度高、抗混迭、不受采样定理约束、可以分析出谐次大于N／2的频谱系数等特点，可方便地应用于电力系统谐波分析及其它各类频谱分析；然后提出了基于非线性最小二乘优化法的电力系统暂态波形分析方法，可准确求出电力系统暂态电压、电流波形中各个分量的角频率、幅值、初相角及衰减常数，并可广泛应用于各类暂态过程波形分析。

With it,t he e lectromechanical transient calculation for AC network and the electromagnetic tr ansient calculation for DC network can be done simultaneously,and the DC line be havior during transient process can be observed more accurately.

该模型能够在对交流网络进行机电暂态计算的同时，对直流网络进行电磁暂态计算，因而能较精确地考察暂态过程中直流线路的动态行为。

Energy function methods are based on transient kinetic and potential energy conservation principle during transient periods.

能量函数法是通过系统暂态过程中暂态动能和势能相互转化规律分析暂态稳定的。

The recursive criterion of transient current protection based on Mallat wavelet transform is presented in order to meet the real-time demands.

对暂态保护原理进一步的深入研究表明，原有的暂态电流保护方案存在着原理性的缺陷。提出了改进的暂态电流保护方案。

This paper presents a new method of the comprehensive parameter identification for real - time transient security analysis.

本文提出了一种应用综合参数识别进行电力系统实时暂态安全分析的新方法、用在电力系统实时暂态安全分析监测系统上，提高了暂态安全分析的实时性、通过对某一实际电力系统的仿真研究表明。这种方法具有好的实时性和实用性。

The concerned research works of VFTO is investigated.A new transient circuit model to the question of the steep front and high amplitude value of VFTO is proposed based on general transient circuit model. The numeric simulation that disconnector switched off short bus has been proceeded by using above circuit model and the comparison of results with the one based on EMTP are given.

首先针对操作GIS中隔离开关所产生的快速暂态过电压上升时间短及幅值高的特点，在一般暂态电路模型的基础上提出了新的暂态电路模型，并利用该模型，对GIS中隔离开关切断短母线的等值电路进行了数值模拟，并与电磁暂态程序的计算结果进行了比较。

In this paper, the generator model of constant transient voltage and the invariableness impedance model was used, and the saliency of generator is included; through the analysis of the characteristic of the network equation calculation in the transient stability analysis, a new node ordering algorithm is proposed. Better initial value can accelerate the convergence rate of the networking equations, reduce the number of iterations, thus to cut down the amount of calculating time.

本文首先建立了适合于暂态稳定分析的简单模型，其中发电机采用E_q恒定模型，考虑了发电机的暂态凸极效应，负荷采用恒定阻抗模型；研究了电力系统的暂态稳定分析方法，指出目前数值积分暂态稳定计算方法中存在的不足，主要是网络方程的求解速度过慢；分析了暂态稳定计算中网络方程的特点，将稀疏技术应用于网络方程的求解，提出了一种新的节点编号方法——最小度最小有源节点道路集算法，减少了网络方程的计算量；在进行交替迭代求解时，将预测算法应用于每一积分步网络方程功角和电压的初值估计当中，应用自回归算法和广义延拓算法，期望给出一个更有效的电压和功角初值方案，来加快方程的收敛过程，减少方程迭代的次数，以提高计算速度。

It also becomes more difficult to model and simulate power grid. Traditional"Quasi-stationary"phase models can't be used for studying electromagnetic transient phenomena; on the other hand, the EMTP models can be used to analyze the electromagnetic transient accurately, but for the limitation of the step size, it can't be used to simulate the large network with a high speed.

这对电力系统的建模和仿真提出了更高的要求，传统的机电暂态模型由于建立在&准稳态&假设基础之上，因此不能用来仿真变化迅速的电磁暂态过程；而电磁暂态模型，虽然能准确反映电磁暂态过程，但由于仿真步长很小，仿真速度受到限制，不适合用来仿真大型电力系统。

The dynamic phasor model is based on the time-varying phasor, which not only breaks the quasi-stationary assumption, but also overcomes the maximum step size constraint of regular transmission line, so it can be used to analyze the fast electromagnetic transient phenomena at a higher speed.

传统的机电暂态模型由于建立在&准稳态&假设基础之上，因此不能用来仿真变化迅速的电磁暂态过程，而电磁暂态模型，虽然能准确反映电磁暂态过程，但由于仿真步长很小，仿真速度受到限制，不适合用来仿真大型电力系统。

For this topic,on the basis of compar...

针对这一问题，笔者在比较电磁暂态仿真和机电暂态仿真模型与方法的基础上提出了一种电力系统电磁暂态-机电暂态混合仿真的通用接口方法。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。