中长期电压稳定时域仿真软件应用评估

大规模电力系统的中长期电压失稳是一个缓慢的过程,其发生和变化与系统中慢速元件的动态行为紧密相关,研究电网中长期电压稳定问题需要选择能够反映其动态过程的仿真软件。选择PSS/E、PSD-FDS、Eurostag、PSASP和DSATools 5种仿真软件,通过仿真实验、程序参数、应用案例的对比分析,在原理算法、计算规模、元件模型、接口界面和实际应用等方面评估了各软件中长期时域仿真的特点、功能和适用范围,结果表明,PSD-FDS拥有更适合中国电力系统的模型库和数据格式,在实际系统中应用也更广泛,较其他软件更适用于中长期电压稳定研究。     

基于BPA和PSASP程序的短路电流计算比对

BPA和PSASP程序是目前国内使用较为普遍的2种短路电流计算程序（使用率在80%以上）,使用这2种程序的计算结果存在较大差异,已影响到电网的决策。结合国内现行的短路电流计算标准,分析研究了基于潮流和基于网络条件下短路电流计算结果存在差异的原因。研究发现,造成计算结果差异的主要原因是缺乏统一的标准,另一个重要原因是计算...     

Development and application of software for the analysis of magnetically induced subsequent fault (MISFault)

As an initial electric fault occurs, the fault current would result in a strong magnetic force and torque exerted on the power line conductors. The rotational magnetic torque, in turn, would make the power lines with sags swing and may bring them to close proximity or in contact with one another, causing a subsequent fault. For the analysis of the magnetically induced subsequent fault (MISFault), software has been developed as the end product of a multi-year research project sponsored by Duke Energy Company. The software is capable of predicting the smallest distance between the power line conductors during their swing procedure, from which one can predict the probability of the magnetically induced subsequent fault; and determine the allowed span length range from consideration of eliminating the subsequent fault, which is anticipated to be useful for a utility in long span design. The software has been tested and the accuracy of its computation results has been validated by verifying that the energy conservation law requirement is well satisfied. The MISFault software is being used by Duke Energy Company. It is user friendly and is expected to be useful to a utility for eliminating the magnetically induced subsequent fault.     

开关磁阻起动/发电系统功率变换器传导EMI建模研究

在分析开关磁阻起动/发电系统功率变换器产生的传导电磁干扰(EMI)传播通道(包括共模和差模)的基础上,采用等效电路模型的方法建立了功率变换器的传导EMI时域模型,并用Ansoft-Simplorer软件以及傅里叶级数分解的方法分析计算了功率变换器产生的EMI频谱,研究结果表明在低频段(小于100 kHz),功率变换器的差模干扰占据主导地位,在高频段,共模干扰占据主导地位。将仿真结果与实测的干扰电压波形和EMI频谱结果进行了比较,验证了所建模型和所用方法的正确性。     

无功/电压动态识别与处理

研究了一种地方电网无功/电压动态识别与处理的新方法。在提 出电压预警区概念的基础上，建立了一种简单实用的电压状态识别判据，并采 用分层控制的思想，利用系统中可用的无功调压措施，对识别出的越电压预警 限的节点电压进行处理。用IEEE 22节点系统对软件进行测试，对一 种同时存在电压越预警上限和告警下限的情形进行计算，并用潮流程序对最终 控制策略进行了校验。     

电力系统多仿真软件数据池在华东电网的应用

多种大型系统仿真软件在科研生产上的广泛应用 ,系统性的数据的编辑、整理、转换等工作成为应用生产科研部门进行仿真计算的工作重点之一。提出了基于数据池的电力系统仿真软件数据转换思想 ,通过 SQL关系数据库对数据池进行访问和维护。数据池提供了广泛的数据支持 ,具有各种模型下的电力元件参数转化、控制器建模、WARD等值等功能。通过对华东系统的实际应用 ,表明数据池对电力系统规划、运行和科研都具有一定的实用价值     

电能质量监测系统数据高速采集和实时处理的协调优化分析及应用

在电能质量监测系统中,数据的高速采集和实时处理的协调一直是实际系统构建的关键问题。在深入分析高速采集和实时处理模式的基础上,分析了各种影响高速采集和实时处理软件实现的因素,在系统的软硬件构建方面综合探索了多种协调优化方法,并以电网谐波实时分析系统的建立为例进行了应用研究。工程实际应用结果表明,优化后的谐波实时分析系统在采样精度、分析电网高次谐波、实时电量存储方面均有较好的实时性,从而为电能质量实时分析系统的设计提供了可供借鉴的方法。     

INTEGRATED SOFTWARE FOR OPTIMAL DIRECTIONAL OVERCURRENT RELAY COORDINATION

ABSTRACT

This paper reports the development of fully integrated software for the optimal directional overcurrent relay coordination of interconnected power systems. Different software packages like load flow analysis, fault analysis, determination of backup/primary relay pairs, main relay coordination program, etc. have been integrated. The program could be run as an interactive package or as an off-line package, depending upon the choice of the user. The information needed for the coordination is stored and used by the software. No data base management packages are needed to manage huge data generated by the program. The software uses an efficient method to generate, store and retrieve the data as per the requirements of the coordination. In the Interactive mode, the information about the coordination time interval, range of the relay settings, limits to the maximum and minimum time of operation of the relays, etc., are supplied. All other relevant data needed for coordination are generated by the software package itself. The usage of the program is illustrated by a case study involving the SPC 26-bus power system.     

Object-Oriented Approach to the Enhancement of Energy Management Systems Software Engineering

This paper presents the idea of an operational model of a power system as the background for Energy Management Systems (EMS) software. Due to the Object Oriented Approach, with use of the proposed model, all kinds of standard power system analyses can be provided. The objects and their hierarchy is organized in such a way that all inconveniences well known in practical applications (multiwinding transformers, mutually coupled lines, busbar couplers, tapped lines, dummy nodes, control systems, FACTS devices, etc.) are taken into account and included in consistent data structures. Possibilities for a clear connection between operational models and numerical models of power systems are indicated.     

大型异步电动机起动过程的机-网暂态仿真软件研究

建立了集中耦合参数的电网模型和状态方程的电动机数学模型。利用该模型进行仿真,可以得到电动机起动过程中的电流、电压、磁链、传速等值。开发了电网与电动机的接口。利用该接口,用户可以建立自己的电动机模型并编制仿真程序,和已有的网络程序接口。     

电网静态模拟系统的计算机监控

电力系统静态模拟系统是一种十分重要的仿真实验设备,在电力类高校和研究机关中得到了普遍的应用。到目前为止,静模系统的监控手段大都比较落后、设备复杂、维护困难、使用不便,限制了这一技术的进一步发展和应用。本文在总结前人工作的基础上,设计出了以高性能工业控制机、PLC可编程逻控制器、NI多功能数据采集板为硬件核心;以虚拟仪器编程环境Lab-Windos为软件平台的静莫模计算机监控系统,解决了现有静模系统存在的种种问题,大大提高了静模系统的性能指标。     

基于电场分析的ADSS光缆挂点研究

近年来,ADSS光缆凭借其独特的优点,在电力系统通信网络建设中被广泛应用。与高压输电线路同塔,架设的ADSS光缆,在一定的气象条件下,在机械应力与高压输电线电场的共同作用下发生电腐蚀,严重时导致运行中断,发生断缆事故,威胁光缆的可靠运行。因此,为ADSS光缆选择合理的挂点范围对ADSS光缆的正常运行起着至关重要的作用。研究各种环境条件下,不同运行情况及各种电压等级的高压电力线路周围空间电场的分布情况非常必要。本文通过ADSSPE软件的模拟计算,分析研究实例-广州黄埔电厂至棠下变电站发生24芯ADSS光缆断裂事故,建立模型计算绘制电场和电压等值图,采用矩量法计算高压输电线路铁塔附近产生的三维电场,利用包括空气和多层土壤在内的多层介质的格林函数,以各段导体的泄漏电流为待求变量,计算频域下输电线路及铁塔附近的电场分布,并与实测结果相比较,证实方法的有效性。该研究为合理选择ADSS光缆的挂点范围与指导光缆选型提供理论依据,对工程应用和电网安全运行具有显著的经济技术和社会效益。     

高压直流建模研究的相关问题

总结了电力系统稳定性分析中高压直流输电系统的一般性建模方法;讨论了直流模型的分类及模型的适用性;分析了常用商用电力系统分析软件中的直流模型,建议开发商适当增加内置直流模型与用户自定义模块间的接口,以拓展直流模型的适用范围;重点分析了基于采样数据建模方法和动态相量理论对直流换流器准稳模型的改进。认为采样数据建模方法建立了适合于电力系统次同步振荡研究的换流器小信号模型,但不能用于电力系统暂态稳定仿真计算中;动态相量法推导了换流器的大信号模型,但仍不能正确反映换相失败现象和不对称工作条件下高压直流系统的动态行为。认为在大规模交直流电力系统的暂态稳定性研究中,机电-电磁混合仿真思路较有潜力,而其关键问题在于各种扰动下电磁暂态仿真范围的合理确定。     

Operation and control of a hybrid microgrid containing unbalanced and nonlinear loads

This paper shows how the power quality can be improved in a microgrid that is supplying a nonlinear and unbalanced load. The microgrid contains a hybrid combination of inertial and converter interfaced distributed generation units where a decentralized power sharing algorithm is used to control its power management. One of the distributed generators in the microgrid is used as a power quality compensator for the unbalanced and harmonic load. The current reference generation for power quality improvement takes into account the active and reactive power to be supplied by the micro-source which is connected to the compensator. Depending on the power requirement of the nonlinear load, the proposed control scheme can change modes of operation without any external communication interfaces. The compensator can operate in two modes depending on the entire power demand of the unbalanced nonlinear load. The proposed control scheme can even compensate system unbalance caused by the single-phase micro-sources and load changes. The efficacy of the proposed power quality improvement control and method in such a microgrid is validated through extensive simulation studies using PSCAD/EMTDC software with detailed dynamic models of the micro-sources and power electronic converters.     

多馈入直流输电系统受端电网动态特性

以2010年夏季大方式下的南方电网为对象,详细研究了其受端广东电网内部严重故障和直流输电线路故障对南方互联电网其他直流输电系统的影响,以及对整个南方电网系统的影响。首先用机电暂态仿真软件PSD-BPA进行仿真计算,筛选出对系统有严重危害的故障;然后对原始广东电网进行等值,建立包含详细直流模型的适当规模的网络结构;最后用PSCAD/EMTDC电磁暂态仿真软件对等值网络进行仿真模拟。研究结果表明,广东电网结构坚强,能够满足安全稳定导则中一级、二级安全稳定标准要求。     

Controllable analog emulator for power system analysis

This paper details the development of a controllable analog emulator for power system analysis. The emulator consists of reconfigurable analog hardware for power system emulation and a digital computer, along with associated software, for configuration, control, calibration and data acquisition. The analog hardware is fully controllable via the software interface. System parameters, initial conditions, integration, faults and contingencies can be created or altered via the software with no changes or manual intervention to the analog hardware. This advance overcomes one of the larger drawbacks of older analog computers, which was the need for manual configuration and calibration. The emulation methodology is presented in this paper as well as power system modeling, both theoretical and in analog hardware. The software interface and control is also presented. To validate the operation of the emulator two examples are shown from a prototype emulator. The first being a steady state power flow solution, the second computes the critical clearing time of a generator fault for transient stability.     

基于高性能单片机的功率直流开关电源的设计

本文基于高性能单片机设计了数字控制的功率直流开关电源。首先介绍了该电源的原理及整体设计方案,其次介绍了部分关键电路的硬件设计,采用软件方式来实现功率直流电源的数字控制,给出了主程序及部分关键部分的程序流程图。该电源具有输出电压连续可调、精度高、电路简单、操作灵活等优点。     

Power system disturbance identification from recorded dynamic data at the Northfield substation

For a power industry undergoing deregulation, the growing number of power marketers and independent power generators increases the variability of power flow patterns in an interconnected power system, thereby making the prediction of critical operating conditions and limits more demanding. Consequently, transmission system operators need new tools to understand the effects of disturbances. Among these needs are tools to classify and identify disturbances as they occur on the power system. In this paper, power system disturbance data from the Northfield substation dynamic recording device in the US New England power system are analyzed and their features extracted. Then a classification method is used to identify the disturbance. Events with multiple disturbances are also addressed. A MATLAB-based software, called ‘Event Analyzer’, has been developed for the disturbance identification.     

电磁暂态程序EMTP在电力系统的应用

随着电力系统的发展、计算机的普及和计算能力的不断提高,电力系统数字仿真已成为电力系统试验研究、规划设计和调度运行的重要工具。本文介绍了电力系统经常使用的电磁暂态仿真软件EMTP的发展、原理、结构和应用,并对其使用方法做了详细介绍。     

采用面向对象方法开发用于电磁暂态及电力电子仿真程序的图形输出软件

电力系统电磁暂态及电力电子仿真程序（Electro Mag-net Transients and Power Electronics Program,EMTPE）是用于电力与电力电子装置的科研、设计和运行的电磁暂态分析工具。作为该工具的组成部分。要求与EMTPE计算程序配套的图形输出程序提供直观快捷的计算结果处理、显示和分析功能，以图形方式显示各种类型输出变量随时间或频率变化的波形和曲线，并具备数值分析及图形后处理等多项功能。为满足这些功能要求并结合实际工程需要，作者采用可视化面向对象技术，在Windows 9x/NT操作系统平台上开发了基于Microsoft VisualC 5.0的EMTPE通用图形输出软件（Plotting Transient Curve,PTC）。在此简述PTC1，0软件的设计与实现要点，同时介绍PTC软件的功能及应用。