地区电网实时电能质量数据管理系统

提出了一种基于局域网的地区电网电能质量实时数据管理系统，介绍了该系统的整体结构、各构成部分的功能与特点，以及数据传输和处理方式。该系统集电能质量在线监测和数据管理功能于一体，实现了电网电能质量指标的实时集中管理。     

电网谐波的实时测量

本对电网谐波的实时测量进行了探讨，并分析了影响电网谐波测量的因素和实现实时测量的方法。在伟福仿真系统下，对实时测量算法进行了仿真测试。     

同相供电补偿电流实时检测方法

平均功率法同相供电补偿电流检测,需要积分一个周期才能得出检测结果,存在实时性差的缺点,且受电网电压畸变影响。提出了两种补偿电流检测方法:有延时的两相构造和无延时的两相虚拟。通过理论分析和仿真结果证明,两种方法都能达到对同相供电系统补偿电流的实时检测,平衡三相,消除三相谐波及无功电流。后者算法简单,动态跟踪速度快,检测精度高。     

同相供电补偿电流实时检测方法

平均功率法同相供电补偿电流检测,需要积分一个周期才能得出检测结果,存在实时性差的缺点,且受电网电压畸变影响.提出了两种补偿电流检测方法:有延时的两相构造和无延时的两相虚拟.通过理论分析和仿真结果证明,两种方法都能达到对同相供电系统补偿电流的实时检测,平衡三相,消除三相谐波及无功电流.后者算法简单,动态跟踪速度快,检测精度高.     

On power quality indices and real time measurement

Power quality (PQ) indices are used to quantify the quality of the power supply and serve as the basis for comparing the negative impacts of different disturbances on power networks. To overcome the limitations and deficiencies of the practical applications of some power quality indices in common use, a set of three new indices, namely the fundamental frequency deviation ratio (FDR), waveform distortion ratio (WDR), and symmetrical components deviation ratio (SDR) are proposed in this paper to summarize different types of power disturbances in a comprehensive manner. As instantaneous quantities, these novel indices can reveal the time varying characteristics of power disturbances in real time. Hence, the new PQ indices can well accommodate practical waveform distortions in power networks, which may be caused by multiple types of time varying power disturbances. They can therefore be further used to evaluate both the effectiveness and dynamic responses of PQ mitigation equipment in practical applications. To fully realize the advantages of the new PQ indices, a novel Atom (transform kernel) based time frequency transform and its recursive algorithm are also proposed as the supporting measurement technique. The new Atom approach can continuously measure the instantaneous frequencies and amplitudes of signal components in a nonstationary disturbance waveform with high accuracy, and then update the new PQ indices at each sample. The effectiveness of the new PQ indices and the supporting measurement technique were ascertained using various PQ events, both simulated events and those recorded at an industrial site.     

谐波下的电能计量及电能质量分析方法

对谐波下电能计算和电能质量分析的方法进行了讨论,着重对积分电能算法和FFT变换方法进行了对比介绍。     

基于PMU的电力系统暂态稳定实时快速预测的研究

提出一种基于ＰＭＵ 对发电机实时测量功角来预测电力系统暂态稳定性的方法。通过采集功角数据,用多项式逼近去快速预测它未来的变化,同时为提高精度采用智能动态修正,然后判断多项式是否存在极值,若存在可预测系统首摆稳定,反之则不稳定。仿真结果表明,该方法对首摆稳定性的预测是准确和有效的。     

分散型电源与新供电系统

在大电网覆盖的地区,分散型电源装置与电力系统联络会出现许多新情况.介绍适合分散型电源与系统联络的新供电系统.     

光伏接入牵引供电系统对电能质量的影响

提出将光伏系统作为牵引负荷电源之一,与电力系统共同给牵引负荷供电的方案。光伏系统在27.5k V侧接入牵引供电系统,分析牵引负荷特性和光伏系统输出特性,推导计算光伏系统接入前、后对电力系统侧电能质量的影响;针对不同工况对光伏接入后电能质量的影响进行仿真分析,基于实测负荷数据对光伏系统接入前、后电能质量的影响进行验证。结果表明:所研究的光伏接入方案对电力系统侧三相电压不平衡度不产生影响,对三相谐波畸变率以及功率因数的影响与接入光伏系统的大小有关。     

供电服务质量体系模型的构建及评价

介绍了国外供电企业实施的顾客满意度测评所采用的满意度指数模型和设定顾客满意度指标体系所遵循的基本原则。叙述了上海市电力公司顾客满意度测评指标体系的构建框架，并对现有顾客满意度的测评方法，应用后的总结与分析，提出了建立供电行业服务质量体系模型及三方评价机制，用以改进供电服务质量和增强供电服务能力。     

开关电源模块并联供电系统

基于C8051F005单片机设计实现开关电源并联模块供电系统.系统由两块DC-DC模块并联而实现.每个DC-DC模块额定输出功率为16W,系统的额定输出功率达36W.输出电流在0.5～4.4 A范围内变化时,单个DC-DC模块经扩流后输出电流可以达到0.5～3.5 A任意可调,两个DC-DC模块电流按任意指定比例自动分配电流.电流分配方法采用主从均流法,控制精度很高,电路简单,效率高.经过测试,系统效率可达78％,并具有负载短路保护功能.系统DC-DC模块使用雕刻机制板,提高稳定性和抗干扰能力.     

电网调度自动化系统中计算机对其供电质量的要求

从电压波动、频率波动、波形失真等方面分析了影响电网调度自动化系统中计算机供电质量好坏的因素,阐述了瞬变浪涌下跌、瞬变脉冲(又称电压闪变)、瞬时停电及三相不平衡给计算机电源带来的影响,导致计算机运算错误或破坏存储的数据和程序.提出了改善电源质量的相应措施:采用隔离变压器可隔离电网上的瞬变干扰,达到电磁屏蔽的作用;加装滤波器可衰减来自电网的电磁干扰和射频干扰;系统配置稳压器和电力专用在线式不间断电源(UPS)等可减少电源系统中的浪涌、噪声、电压下跌等现象.     

Real time digital power system simulator design considerations andrelay performance evaluation

Environmental pressures, right of way problems for new transmission lines, large scale system interconnection and increasing power demand especially in developing countries call for new transmission technologies. Use of FACTS and HVDC is gaining momentum. Relaying problems in such systems require a sophisticated approach and numerical technology using high grade processors offers a promising solution. To establish the performance of such relays which are designed more as powerful schemes rather than as a conglomeration of individual relays, detailed testing is required using an elaborate real-time simulator model. These tests are not only necessary during design and development but also are required by the utilities as a part of their acceptance. Highlighting the requirements of a hybrid real-time simulator including the complete spectrum of power system dynamics, this report describes an analog cum digital model used for real-time assessment of system performance. SVCs, HVDC, ASC and CSC can be modelled fully digitally by computer simulation and transient real-time data injection as well as by an analog method using physical simulation with original converter controllers for performance evaluation of numerical relays under real system conditions. As an example of the use of this simulator, tests on a numerical EHV-line relay are described and the relay performance is analyzed     

河北南网实时动态监测系统的建设

结合河北南网实时动态监测系统的建设,论述了该系统的结构、主要功能和特点,以及确保其相关技术性能的重要性。     

构建供电企业的优质服务体系

随着电力体制改革的不断深化．使原有的电力产业链受到了巨大的冲击,构建供电企业优质服务体系已成当务之急,通过供电企业优质服务体系实现供电企业的可持续发展。     

供电系统谐波的产生、危害及其防护对策

谐波是电力质量的重要指标 ,供电系统中大量具有非线性特性的电气电子设备是产生谐波的主要原因。综述了谐波的危害及其防护的对策。     

激光供电在串补测量控制系统中的应用

随着激光技术的飞速发展,激光供电技术在串补保护测量控制系统中的应用越来越广泛。文章介绍了激光供电的原理及其在电力系统串补保护测量控制系统中的应用,分析了各串补站保护测量控制的激光供电设备在运行中出现的问题．找出了激光供电设备的运行及维护方法。不断地改进激光供电系统,提高激光供电设备运行可靠性,保证了串补保护测量控制系统的稳定运行。     

供电企业供电服务质量评价体系研究

构建了供电企业供电服务质量评价指标体系,利用逼近理想点法和专家打分法建立了指标权重的计算模型,用下凹型效用函数对单指标进行评分,最后,以算例验证了该评价方法的有效性。     

一种连续供电系统双电源快速柔性切换方法

针对焦化生产行业一类负荷电能质量不合格或双电源切换不成功导致煤气异常排放问题,提出一种利用复合开关实现低压双电源快速柔性切换方法。该方法切换速度快,切换过程不产生冲击电流、过电压,保证设备正常运行。切换过程由协调控制器协调控制,各设备间信息流用IEC 61850模型表示,适应未来电网发展。实例分析说明了所述双电源快速柔性切换方法的实现和快速柔性切换复合开关的基本特性。     

TransientMeter: a distributed measurement system for power quality monitoring

This paper describes the design and the implementation of TransientMeter, a monitoring system for the detection, classification, and measurement of transient disturbances on electrical power systems. TransientMeter relies on a common object request broker architecture (CORBA) as a communication interface, wavelet-based methods for automatic signal classification and characterization, and on a smart trigger circuit for disturbance detection. The system has been successfully applied to detect, classify, and measure disturbances in an industrial environment.