Multifault calculation method for dynamic stability study of electric power systems

For the fault condition in dynamic stability study, balanced faults have mainly been utilized. Recently, however, with the progress of system protective control technologies such as the multiphase reclosing system for a faulted transmission line, the needs for stability software which would be able to calculate simultaneous faults without any restrictions on fault types, total numbers or location, have been increasing. This report presents the newly developed multifault calculation method based on symmetrical components which is able to calculate simultaneous faults without any restrictions on combination of fault types, and total numbers or location. Fault types consist of balanced/ unbalanced ground fault, short-circuit fault, line-out of transmission lines, and short-circuit of series condenser. The proposed method also allows for calculation of faults at an arbitrary location on the line without any topological changes of each symmetrical network even if the faults include line-end faults with ensuring outages. An example was shown to clarify the validity of the proposed method. Moreover, transient stability limits under the various fault conditions also were discussed.     

基于混合光线反射优化算法的最近电压稳定临界点求取方法

传统最近电压稳定临界点求解方法在全局寻优能力和计算效率之间存在矛盾。为进一步增强光线反射优化(OIO)算法的全局寻优能力,基于House-Holder变换和混合多光源策略提出混合光线反射优化(SOIO)算法。算例分析表明所提方法可有效求解最近电压稳定临界点,计算效率高且全局搜索能力强。     

电力系统小扰动稳定的直接法分析

对李亚普诺夫直接法用于分析和评价电力系统小扰动稳定性进行研究.介绍了线性定常系统稳定性的直接法判据,剖析了求解李亚普诺夫方程的算法,引入状态偏差量平方积分指标对系统动态性能进行评价.以4个算例系统的低频振荡为对象,具体研究直接法在电力系统小扰动稳定分析中的应用.研究结果表明:直接法可以正确可靠地判断电力系统的小扰动稳定...     

考虑电动汽车充电负荷的配电系统场景概率潮流分析

提出了一种同时考虑分布式光伏出力和电动汽车充电负荷随机特性的配电系统场景概率潮流分析方法。首先,在考虑车主交通行为与充电模式随机特性的基础上,采用蒙特卡洛模法对充电站典型日内的充电负荷进行模拟,给出充电负荷曲线集。接着,采用K-means聚类分别对充电负荷曲线集和光伏历史出力曲线集进行聚类,给出充电负荷和光伏出力的概率场景集,并以此为基础构建潮流分析场景集。最后,采用前推回代法进行所有场景下的配电系统潮流分析。按场景概率对潮流结果进行汇总,给出概率潮流分析结果。基于IEEE 33节点配电系统的仿真计算验证了所提模型及方法的有效性。     

电力系统最优潮流的计算方法

为了保障电网安全稳定运行,结合当前条件,提出了一种求解电力系统最优潮流方法-原-对偶内点法.介绍了原-对偶内点法的基本思路和算法步骤,并用Matlab语言编写了关于原-对偶内点法的最优潮流程序.计算了14节点系统的发电成本,其结果表明原-对偶内点法对目标函数的优化效果更好,算法的中间量也能为调度提供合理的经济信号.     

电力系统的柔性评价与风电穿透功率极限计算

提出了电力系统柔性概念,通过不确定参数的柔性化表示,建立了面向不确定信息的电力系统柔性评价模型。将柔性概念引入到风电出力随机性的建模研究中,通过风电功率的柔性化表示,提出了基于电力系统柔性评价的风电穿透功率极限计算方法。针对IEEE 30节点系统的研究结果表明,风电功率的柔性化表示充分反映了风电出力随机性强的特点,该方法实现了对风电出力随机性的客观建模,提高了风电并网容量规划方案的灵活性和适应性。     

Microprocessors in electric power systems

The present status of microprocessor applications in various fields of electric power systems is summarized. Special attention is directed towards development trends in the protection field where microprocessor applications are expected to cope with the increasingly stringent requirements for electric power supply reliability. Also discussed are the history, roles, design philosophy and basic schemes of microprocessor-based protective relaying systems. Only recently has their application reached a practical stage after long-term study and repeated field tests.     

Excel在电力系统故障计算中应用

在电力系统的规划、设计与运行中,需要大量的故障计算、分析,手工计算方法是繁锁、困难的。论述了计算电路常用的节点电位法和回路电流法,即从求解节点导纳方程和节点阻抗方程而计算故障点参数。说明Excel是广泛应用的办公软件,具有强大的计算、数据分析和图表处理等功能。用实例阐明了Excel在电力系统故障计算时的方法,即建立系统等值序网络和各序网络节点导纳矩阵,用Excel矩阵求逆函数获得阻抗矩阵,求得阻抗方程,再计算出故障电气参数。Excel软件的应用使故障计算准确、方便、直观。     

电力通信网安全风险计算模型

首先介绍了电力通信网风险三要素:资产、威胁和脆弱性的相关概念并举例进行说明,阐述了三者与风险之间的关系以及如何根据这三个要素计算风险值。为得到较为客观的风险计算结果,对现有的几种风险计算方法进行比较分析得出其优缺点。将风险三要素之间的相互关联性考虑到风险计算过程当中,提出了一种改进的电力通信网风险计算模型,并通过实例对其进行验证,该模型应用灵活,既可用于计算单因素的风险也适用于各因素间组合风险的计算。     

电力通信网安全风险计算模型

首先介绍了电力通信网风险三要素:资产、威胁和脆弱性的相关概念并举例进行说明,阐述了三者与风险之间的关系以及如何根据这三个要素计算风险值.为得到较为客观的风险计算结果,对现有的几种风险计算方法进行比较分析得出其优缺点.将风险三要素之间的相互关联性考虑到风险计算过程当中,提出了一种改进的电力通信网风险计算模型,并通过实例对其进行验证,该模型应用灵活,既可用于计算单因素的风险也适用于各因素间组合风险的计算.     

Analysis of interruptible electric power in deregulated power systems

Assuring appropriate levels of generation capacity adequacy at the minimum possible cost using market-based approaches is a contemporary issue attracting much attention in deregulated power systems. Introduction of interruptible electricity contracts could provide a possible solution to such a problem. However, theoretical frameworks for examining the impacts of these contractual arrangements on system operations have not been maturely developed. This paper presents a probabilistic production simulation based framework for modeling and analyzing interruptible electricity contracts. The interdependence between the pricing models of interruptible electric power and the operations of the whole system is addressed and solved by an iterative coordinating algorithm. The probabilistic production simulation framework allows the uncertainties inherent in both the forced outages of generators and system load demand at the contract delivery time to be taken into account. The proposed approach is capable of achieving comprehensive analysis and systematic pricing for interruptible electric power. A numerical case study is presented to illustrate the effectiveness and validity of the methodology.     

潮流计算在地区电网中的应用

简要论述了潮流计算及其应用于电磁环网的意义,并对某电网两条电源联络线电磁环网进行潮流计算分析,通过潮流计算在电磁环网操作中的作用,说明潮流计算在地区电网中应用的实际意义.     

电力系统的次同步振荡问题

随着我国互联电网规模的快速发展,尤其是(可控)串联补偿装置和高压直流输电的广泛应用,电力系统的次同步振荡问题已经变得比较突出.本文介绍了电力系统次同步振荡问题的起因与危害,回顾了国内外对次同步振荡问题的研究过程,阐述了次同步振荡所研究的感应发电机效应,轴系扭转振荡,暂态扭矩放大以及由其它电气装置(如电力系统稳定器PSS、静止无功补偿器SVC和HVDC等)引起的次同步振荡现象的主要内容,指出了需要进一步关注和研究的问题.     

电铁牵引供电系统无功功率算法仿真技术

通过几组模拟信号和现场信号进行仿真,对几种无功功率交流采样算法的特点、精度进行了分析.提出了适合于电铁牵引供电系统的无功功率测量算法.     

基于SVG的电力系统图形互操作研究

可缩放矢量图形(SVG)作为IEC61970标准推荐采用的公共图形交换的文件格式.提出要实现不同开发商开发的图形文件信息的相互识别和交换,以及实现电力系统图形的互操作的关键是要建立基于SVG格式所组成的电力系统图形文件各元素的语义表达格式标准和电力系统图形文件的组成结构标准,并按照IEC61970描述电力系统资源的标准...     

GIS在电力系统应用的探讨

介绍了地理信息系统的概念及主要研究内容，阐述了国外电力企业在GIS方面的应用，并对GIS在国内电力企业应用的前景进行了探讨。     

Chaotic dynamics of controlled electric power systems

The conditions for appearance of chaotic dynamics of electromagnetic and electromechanical processes in energy systems described by the Park-Gorev bilinear differential equations with account for lags of coordinates and restrictions on control have been formulated. On the basis of classical equations, the parameters of synchronous generators and power lines, at which the chaotic dynamics of energy systems appears, have been found. The qualitative and quantitative characteristics of chaotic processes in energy associations of two types, based on the Hopf theorem, and methods of nonstationary linearization and decompositions are given. The properties of spectral characteristics of chaotic processes have been investigated, and the qualitative similarity of bilinear equations of power systems and Lorentz equations have been found. These results can be used for modernization of the systems of control of energy objects. The qualitative and quantitative characteristics for power energy systems as objects of control and for some laws of control with the feedback have been established.     

基于CVaR的风电场并网容量优化计算

由于风力发电出力与风速具有随机性,风电场接入系统的极限容量较传统电厂的影响更大,计算更困难。条件风险价值理论(CVaR)作为一种新的随机性计算方法被用来建立和求解风电场并网极限容量的优化模型。该模型可计算不同置信度水平下的极限容量,可有效处理置信度水平以外极端情况的影响。引用变换函数,将难以解析的条件风险函数转化为可微的概率密度函数积分形式;引入辅助变量,用离散点代替连续积分计算,简化模型为线性优化问题。仿真算例分别计算和分析了系统接入单个风电场与多个风电场时不同置信度水平下的风电场并网容量,表明方法在处理随机性变量及随机性问题中具有明显、独特、便捷、有效的优点。     

电力系统潮流的自动计算方法

提出一个实用的电力系统潮流自动计算与分析方法,可以实现对年度逐小时电力系统潮流自动计算,其主要特点和功能包括:开发了具有变量范围约束的电力系统潮流算法,可满足潮流自动计算的要求,是实现潮流自动计算的关键算法;运用生产模拟和随机生产模拟方法,给出确定与逐小时负荷水平相应的机组出力及开停机安排的自动发电计划算法。运用该方法构建了潮流自动计算分析系统,并给出了实现潮流自动计算的实例。所提出的算法的收敛性、稳定性较好,能够满足实际计算的要求,可以快捷、准确、高效地开展系统运行分析。