Impact of Distributed Rooftop Photovoltaic Systems on Short-Circuit Faults in the Supplying Low Voltage Networks

This article evaluates the effect of randomly distributed, residential single-phase rooftop photovoltaic systems in the low voltage residential networks, during short-circuit faults on the overhead lines. The important parameters such as the fault current, the current sensed at the distribution transformer secondary, and the voltage profile along the feeder during the fault are examined. A sensitivity analysis is carried out in which the rating and location of the photovoltaic systems in the feeder, as well as the fault location and type, are the considered variables. Moreover, to demonstrate the effect of multiple photovoltaic systems with different ratings and penetration levels when distributed unequally among three phases of the network, a stochastic analysis is carried out. The article summarizes the outcomes of these two analyses to provide a better understanding of the impact of single-phase rooftop photovoltaic systems on the residential feeders during short-circuit faults.     

基于FLN的电力系统三相短路电流计算

本文提出了一种电力系统三相短路电流新方法－人工神经网络方法。该方法使用了自适应模型识别概念和基于广义逆学习算法（ＧＩ）的函数链网络（ＦＬＮ）技术。ＦＬＮ用来估计短路电流基本特征，数值计算实例表明所提出的方法是可行的。     

光伏功率预测系统在某光伏电站的应用

介绍了光伏功率预测系统的系统运行结构和系统功能,以及在光伏电站的具体应用情况,从系统的实际情况和运行数据多方面验证了该系统的优越性和可推广性。     

一起11OkV变压器突发短路故障的分析及预防

介绍了110kV电力变压器突发故障后的诊断手段,分析判断了故障性质.根据变压器运行状况及结构找出故障产生的原因,提出了预防电力变压器突发短路故障的措施.     

Study of a major oscillations event in northeastern area of the Iranian power network

Iranian power system encountered major oscillations in January 2008 in the northeastern area with an amplitude of about 120 MW. Since not all the events and variables had been recorded, a scenario to simulate the recorded oscillations and results of studies conducted to reproduce the oscillations by simulation are discussed in the first part. Tuning of supplementary controllers, such as PSSs, on the generating units and the use of reactive power compensators in the long transmission line to enhance stability and eliminate severe oscillations between the north and eastern areas are investigated in the second part. Eigen-value analysis and participation factors are used to appreciate the nature of oscillations and the required PSS settings. The results show that, by using the properly tuned PSSs and accurate compensation of the reactive power, transient stability and damping of oscillations are considerably improved.     

并联双回线路中间接地短路的互感消去算法

电力系统短路计算中，有零序互感的并联双回线路之一的某线路中间的接地短路计算为零序电流保护整定及灵敏校检等所必需．应用互感消去法对该类短路计算所需的节点阻抗矩阵进行修正．能减少对原始支路信息的人工处理工作量；不需要人为预设故障点．当需要计算线路中间几处分别接地短路或系统中含多对有零序互感的并联双口线路时，能显著降低等值网络节点数目．该方法程序结构简单，使用方便，具有一定的参考作用和实用价值．     

变结构模型短路电流计算方法

提出了一种变结构模型短路电流计算方法。该方法将断路器作为一条阻抗为零的支路来模拟，运用线性网络特性、定理及变结构与变参数的分析方法，将母线上短路时的短路电流等值转移到断路器两侧，导出了相当于在断路器两侧分别发生短路故障时，流过断路器的短路电流的序分量模型和算法。该方法是短路电流计算方法的一个重要补充，使电气设备选择和继电保护整定计算更容易。通过实例验证了该方法的有效性。     

多次短路冲击下变压器绕组轴向模态分析

本文中作者定量地计算了在多次短路冲击下变压器绕组端圈所受的应力。针对不同的端圈应力,对变压器绕组进行了模态分析。     

利用附加节点注入电流法设计静止同步串联补偿器的潮流控制器

从静止同步串联补偿器（SSSC）的原理和特性出发,分析了其稳态特性和数学模型,研究对比了SSSC及其它FACTS装置潮流建模的方法,通过分析节点导纳矩阵和雅可比矩阵的修正,提出了利用附加节点注入电流法建立SSSC潮流模型的方法,并分析了此方法的优点.在电力系统分析综合程序PSASP中,利用用户接口程序实现了SSSC的潮流建模,结合开发的潮流控制模块,解决了含SSSC装置的大系统仿真问题.在EPRI-7节点系统的分析计算中,验证了理论分析的正确性和SSSC潮流模型的控制作用.并与相同控制条件下TCSC特性作了比较,结果表明：SSSC能够以更小的输出功率实现相同的控制效果,而且在小功率情况下,SSSC的优势更加明显.     

电力变压器短路累积效应研究综述

就多次短路所产生的累积效应,提出研究方法,分析了累积效应的机理。从物理规律、现象表现和相关措施三个层次对短路的累积效应进行因果链关联,并针对其中导线微形变进行了一些尝试性研究。     

Power flow model/calculation for power systems with multiple FACTS controllers

This paper presents a new procedure for steady state power flow calculation of power systems with multiple flexible AC transmission system (FACTS) controllers. The focus of this paper is to show how the conventional power flow calculation method can systematically be modified to include multiple FACTS controllers. Newton–Raphson method of iterative solution is used for power flow equations in polar coordinate. The impacts of FACTS controllers on power flow is accommodated by adding new entries and modifying some existing entries in the linearized Jacobian equation of the same system with no FACTS controllers. Three major FACTS controllers (STATic synchronous COMpensator (STATCOM), static synchronous series compensator (SSSC), and unified power flow controller (UPFC)) are studied in this paper. STATCOM is modeled in voltage control mode. SSSC controls the active power of the link to which it is connected. The UPFC controls the active and the reactive power flow of the link while maintaining a constant voltage at one of the buses. The modeling approach presented in this paper is tested on the 9-bus western system coordinating council (WSCC) power system and implemented using MATLAB software package. The numerical results show the robust convergence of the presented procedure.     

大型电力系统的分层并行处理

在解大型线型线网络方程中，本文所研究的分层并行处理是相对稀疏矩阵法的另一种选择。如果Ｎ是电力系统的节点数，那么，这种方法的最大计算理（它与计算机处理所需时间相关）近似正比ｌｏｇＮ分层并行处理所计算的结果与直接求系统矩阵逆的方法所计算的结果是完全一致的。在计算中，每个处理器只需访问很少的内存，由于在本地内存之间传递数据是分层进行的，所以不会产生任何数据传输问题。     

带补偿变压器的500kV自耦变压器短路阻抗调整方法分析

本文中作者介绍了一台带补偿变压器的500kV自耦变压器的两种绕组排列方式的短路阻抗的计算方法,并对两种结构进行了对比分析。     

SFZ7-26MVA/132kV电力变压器的短路试验

介绍了SFZ7 - 26MVA132kV 电力变压器在意大利电工技术中心(CESI) 做短路试验的试验方法及试验结果,并概述了与CESI专家共同探讨的几个技术问题     

我国电力变压器的短路试验及探讨

概述了我国电力变压器短路试验的基本情况,探讨了短路试验的相关问题,并对如何提高我国电力变压器抗短路能力提出了建议.     

110kV级电力变压器短路试验

总结了１９９０～１９９８年９月１１０ｋＶ级电力变压器短路试验的进展情况,并对有关论点进行了探讨。     

利用矩阵变换求解电力系统短路故障的残压变换法

参数不对称元件的出现为对称分量法处理不对称故障的序网联接处理方法设置了障碍.该文针对之以相分量法故障处理方法为依据,建立了相分量坐标下适用于各种短路故障公式化的残压变换法,并以矩阵变换的方式完成不对称短路故障的处理：通过公式变换将该方法应用于对称分量坐标.使用矩阵运算代替对称分量法的传统序网故障变换,以实现不对称短路故障计算,并给出常见故障对应的参数矩阵.对于多重短路故障和含不对称元件的网络都能够直接处理,而计算量却不会明显增大.文中用实例证明了该方法简单实用,而且便于程序实现.     

一种多运行方式下多机系统稳定器设计方法

本文介绍了一种应用非线性规划,同时考虑系统的多种运行方式,将多机电力系统稳定器(PSS)的最佳配置和参数协调问题统一进行求解的方法,并对其目标函数进行了修正.实例结果表明该方法十分有效。