A review on synchrophasor communicationsystem: communication technologies,standards and applications

The present-day power system is a complex network that caters to the demands of several applications with diverse energy requirements. Such a complex network is susceptible to faults caused due to several reasons such as the failure of the equipment, hostile weather conditions, etc. These faults if not detected in the real-time may lead to cascading failures resulting in a blackout. These blackouts have catastrophic consequences which result in a huge loss of resources. For example, a blackout in 2004 caused an economic loss of 10 billion U.S dollars as per the report of the Electricity Consumers Resource Council. Subsequent investigation of the blackout revealed that the catastrophe could have been prevented if there was an early warning system. Similar other blackouts across the globe forced the power system engineers to devise an effective solution for real-time monitoring and control of the power system. The consequence of these efforts is the wide area measurement system (WAMS). The WAMS consists of several sensors known as the phasor measurement units (PMUs) that collect the real information pertaining to the health of the power grid. This information in the form time synchronized voltage and current phasors is communicated to the central control center or the phasor data concentrator (PDC) where the data is analyzed for detection of power system anomalies. The communication of the synchrophasor data from each PMU to the PDC constitutes the synchrophasor communication system (SPCS). Thus, the SPCS can be considered as the edifice of the WAMS and its reliable operation is essential for the effective monitoring and control of the power system. This paper presents a comprehensive review of the various synchrophasor communication technologies, communication standards and applications. It also identifies the existing knowledge gaps and the scope for future research work.     

智能变电站自动化与保护核心IEC标准的进展与分析

近年来,对智能变电站深入研究、推广应用促进了国内外各项技术的标准化进程。基于泛在电力物联网标准体系的研究背景,首先综述了智能变电站自动化与保护技术国内外标准化工作现状;其次阐述了IEC框架下变电站自动化与保护技术的标准构成,详述并分析了其3个核心标准的体系架构及关键技术的进展,其中,IEC 61850包括配置语言、信息模型、服务映射、网络通信,IEC 60255包括保护开入/开出数字化、传输时延、同步相量测量,IEC 61869包括总体技术要求、中压低功率互感器、数字接口与合并单元。最后从体系架构、信息模型继承、功能标准制定、全维度信息安全、国内外标准一体化研制等5个方面提出了相关建议。     

基于多Agent技术的电力系统集成保护

研究了多Agent技术应用于集成保护中解决各种保护功能的协调问题.通过一种基于多个算法功能的电力系统集成保护方案,阐述了集成保护的基本原理.应用Agent技术的结构原理构建了基于多Agent技术特点的集成保护系统结构.进一步研究了基于多Agent技术集成保护系统的方案运行过程,分析了集成保护系统通信及保护可靠性问题,通过理论分析和实例说明了基于多Agent技术的集成保护的优越性.     

基于光纤网的后备保护系统的研制

在继电保护体系中,后备保护不正确动作对系统的影响非常大,随着电网结构日趋复杂和运行方式日益灵活,后备保护的整定也日益复杂和难以协调,这也是造成电力系统级联跳闸的主要原因。文章研制了基于光纤网的后备保护系统,利用网络和通信技术,在传统后备保护系统中增设了集中智能控制处理环节,增强了电力系统安全防御第一道防线的安全可靠性。文章阐述了该系统的结构、功能设置和算法, 并进行了详细的仿真,仿真结果验证了该保护方案的可行性和优越性。     

双目标递进式断面过载保护控制协调优化策略

输电断面过载易引发大规模连锁性事故。利用合理有效的保护控制措施降低断面功率输送压力,可以避免恶性事故的发生,对于电力系统的安全运行具有重要意义。针对输电断面过载问题,提出一种双目标递进式保护控制优化模型及相应的协调策略。将过负荷保护作为网络结构控制手段,与控制资源进行协调配合,以获得更优的断面过载调整效果。首先基于潮流追踪算法,剥离电力系统中的源荷输电路径。将源荷路径作为基本调整单元,引入过负荷保护动作量作为待优化参数,构建两层优化目标:以降低负荷损失量为第一层目标,以提高系统安全裕度为第二层目标,通过嵌套式寻优算法进行逐层求解。所提策略在潮流不越限基础上,优化发电机、负荷调整方式及过负荷保护动作变量。算例结果验证了该方法的有效性。     

WAMS在电力系统分析和控制中应用的新进展

基于PMU/APMU的广域测量系统WAMS的出现,主要源自电力系统安全稳定控制对于量测量在时间上同步以及监控范围在空间上广域的需求。为提高电网安全稳定监控水平,利用综合法、分析法归纳和分析了暂态稳定预测及控制、静态电压稳定控制和基于轨迹的暂态稳定分析方法的最新进展。研究表明,采用相对功角或角速度判别系统的暂态功角稳定性并实施控制策略,能很好反应系统电力系统本质及运行情况。     

基于PMU/SCADA的变电站自动化广域安全闭锁

分析了广域安全环境下电力系统稳定运行对变电站自动化闭锁逻辑的应用需求,设计了包含广域保护层、变电站层、间隔层和底层的变电站闭锁体系结构。基于相量测量单元和电力SCADA系统的数据信息,在广域保护层构造了4种安全闭锁约束指标,并将约束指标作为调度中心发送操作指令和电网自我调节的闭锁约束条件,完成了广域保护层在线闭锁逻辑的设计。最后介绍了广域保护层在线闭锁功能的实现以及变电站层闭锁功能的配置方法。     

A cooperative protection system with an agent model

The authors propose a new concept, the “relay agent”, to realize a cooperative power system protection system, which consists of distributed equipment combined with a communication network to cooperate in the realization of adaptive protection functions. Relay agents move between equipment to utilize data and functions distributed over the power system. In the paper, relay agents are classified by their roles and protection functions under some typical conditions are simulated. Consideration based on the simulations indicate that the concept enables the protection system to keep an isolated zone minimum against any changes in power system conditions and to secure high reliability of the protection system with less redundant hardware. The new concept “relay agent” will provide a powerful means of advanced protection functions by combination of microprocessor technology and information communication technology     

台山电厂2台国产600 MW机组厂用电监测管理系统介绍

介绍了广东台山电厂2台600 MW机组厂用电监测管理系统的监控网络结构,该系统采用分层式结构,具有站控层、网络层、间隔层3层设备及站控层、间隔层2层网络。阐述了该系统的功能,包括能量消耗监测、电能质量分析、运行监视、报警、故障诊断等,并与传统的采用分散控制系统(DCS)输入/输出(I/O)卡件将现场信息送入集控室比较,得出采用厂用电监测管理系统经济效益优于传统方法的结论。     

An expert system for switch operation planning on line dispatching

An expert system is presented that produces the operation sequence for disconnecting apparatus from a power system under normal operating conditions. To maintain the reliability of power supply on the network during the operation, the operation sequence must be produced in due consideration of network states, such as load factors and routes of transmission line. Besides, since the network which the system manages includes many high-voltage consumers, the operation sequence for each consumer should be divided into detailed switch operation sequence. To produce a detailed switching operation sequence simultaneously with macronetwork operation sequence, we introduce the multilayered object-oriented network model for the knowledge base of this expert system. Each layer of this model represents network configuration in the different degree of detail, and the consistency between states of layers is maintained by an interlayer message-passing mechanism. On the layer which represents apparatus and their connections in detail, the inference engine can generate the switching operation sequence. On another layer which represents control centers and consumers, the inference engine can search for routes of power supply and can generate the sequence of changing over the network. Therefore, by using each layer properly, the inference engine can produce various kinds of operation sequences. Furthermore the object-oriented network model facilitates maintenance and extension of the system.     

网络型电能质量管理系统

为了提高电力系统供电的电能质量，江苏电网已建立了一套网络型电能质量管理系统。该系统是一个分层、分布管理系统，系统分成三层，即监测终端、地区电网电能质量数据管理系统和中心数据管理系统，以广域网为层间通信介质。介绍了系统结构、各层的功能和数据库结构，并简要地介绍了该系统在江苏电网中的应用情况。最后，提出了提高系统功能的设想。     

Power Substation Automation Using a Knowledge Based System - Justification and Preliminary Field Experiments

Conventional automation and control devices are passive and responsive. These devices typically "respond" to changes in the power system as measured against fixed thresholds and preset limits. These systems are designed to prevent catastrophic failures and incorrect operations and work well for general data acquisition and remote supervisory control. How ever, feedback control, system diagnostics, advanced protection, and contingency control are difficult to implement on the ever changing power system with these conventional approaches. Knowledge based systems have the potential for following the changes in the power system and adjusting decision criteria accordingly. Decisions can be made on a more complete data base which is constantly adjusted to changes ir system parameters and operation. This paper describes the various functions where knowledge based systems could ideally be used. The use of a knowledge based, adaptive system approach for diagnosing distribution system disturbances and equipment failures is presented. Two field experiments are described.     

电力系统保护OTN通信网路由均衡规划方法

针对电力系统保护光传送网(OTN)通信网路由规划光层链路资源占用不均衡问题,提出一种电力系统保护OTN通信网路由均衡规划方法。首先,阐述了电力系统保护通信网的结构与业务需求;然后,在构建电力系统保护OTN通信网网络分层模型的基础上,量化电层和光层指标作为约束条件,提出了含传输时延、业务可靠性、电层资源占用率和光层资源占用率的路由均衡最优规划模型和模型求解方法;最后,实验验证了该规划方法的有效性。仿真结果表明,该规划方法可以避免高负载光层链路和光层节点的出现,降低了光层链路占用率标准差。     

基于同步相量的电力故障录波监测系统

大电网互联给电力系统的安全稳定运行提出了新的挑战,电力故障录波监测系统要满足互联系统在发生大范围、长过程严重故障后事故分析的要求。文章介绍了DPR-2E型电力故障录波监测系统。DPR-2E系统的装置硬件采用Motorola PowerPC和ADI BlackFin DSP组成双CPU系统,软件采用Linux嵌入式实时操作系统,全面提高系统的可靠性和抗干扰能力;该系统基于同步相量测量平台,利用同步时钟信号可为电力系统实时动态监测系统提供大量原始数据;高稳定度的恒温晶振和高精度守时技术全天候保证秒脉冲信号的准确性,为大范围故障分析提供同步保证;改进的prony算法可准确迅速判定电力系统低频振荡;高精度测距技术能够很好地适应线路参数变化带来的测距误差。DPR-2E系统集故障录波、测距、同步相量、实时监测和连续记录为一体,为超长时间、大范围和发展性的事故分析提供了可靠的数据来源。     

基于传感器网络的配电网保护通信技术

配电网设备复杂多样,容易受到自然界的各种干扰,国内配电网的智能化建设刚刚起步,配电网的灾害监控、运行管理、故障诊断存在不足。研究了基于传感器网络的配电网保护通信技术,以实现电网灾害的在线监测与预警。通过支撑多任务的传感器节点阵列布置、网络体系的架构分级,采用图形化、可视化手段,对配电网进行全方位的监测。建立了可视化电网监测数据管理系统,能够针对数据进行检索、统计、计算处理,生成各类二次数据,便于有关人员对电网运行状态和趋势进行分析和决策。     

电力移动作业PDA安全接入系统设计与实现

分析了传统电力移动作业个人数字助理(PDA)接入系统可能存在的安全风险,设计和实现了更为安全的接入系统,对其总体架构及功能进行了详细分析。该系统可进行双向证书认证、数据保密传输、安全访问控制、网络隔离与安全数据过滤、实时监控管理,可有效解决电力移动作业应用的安全防护问题。     

基于PMU的中压配电网精确故障定位方法及关键技术

中压配电网精确故障定位技术对于减少电力系统的停电时间和停电频率,提高供电可靠性具有重要的意义。同步相量测量技术的广泛应用,为在配电网中实现故障的精确定位奠定了基础。文中对以配电网同步相量测量装置（D-PMU）为基础的中压配电网精确故障定位方法的研究进行了分析和展望。在对中压配电网故障定位技术现状进行分析的基础上,阐述了目前配电网精确故障定位面临的机遇与挑战,提出了实现精确故障定位的前提条件。在此基础上,围绕着中压配电网精确故障定位研究的主要科学问题,提出了需要重点关注的研究内容,并对相关的研究思路和技术路线进行了详细的阐述。     

基于PSCAD/EMTDC的电力系统中性点接地方式研究

电力系统中性点的运行方式涉及系统的电压等级、电力网络结构、绝缘水平、通信干扰、接地保护方式和保护整定等许多方面,是一个综合性的复杂问题。目前,对电力系统的中性点接地方式的选择,多基于以往运行经验。本文利用PSCAD/EMTDC软件建立了电力系统的中性点运行方式的仿真模型,模拟了各种运行方式下,线路上发生单相接地故障时,电气参数的变化情况,并综合考虑系统可靠性、绝缘水平和继电保护的要求,确定了各种运行方式的适用范围。文中所建模型及结论对于分析高阶、非线性的电力系统暂态过程具有借鉴意义。     

分布式仿真系统的鲁棒性及其分析方法初探

基于分解协调计算模式的分布式仿真技术可有效地利用各调度中心的计算资源和数据资源,实现一体化仿真分析。然而,分布式仿真需要在广域网络环境中进行,计算过程可能受到各种不确定因素的干扰。因此,有必要研究扰动情况下分布式仿真的收敛性和正确性,即分布式仿真系统的鲁棒性。针对典型分解协调计算模式,文中提出了电力系统中分布式仿真系统鲁棒性定义,并针对通信故障这一关键扰动形式给出实用的鲁棒性评估方法。进一步,针对一类分布式潮流计算过程,构建其控制系统模型,给出其鲁棒性分析结果。所提出的鲁棒性评估和分析方法具有通用性,可适用于多种分布式仿真应用系统相关分析,有助于提高分布式仿真效率、评价分布式仿真系统鲁棒性以及指导协调算法的改进。     

An open-system approach to power system protection and control integration

Data packets based high-speed digital communications have opened the door for new types of applications in power system protection and control. The main obstacle in adopting Ethernet-type networks for time-sensitive communications was the data transfer characteristic of these networks. With baud rates in the gigabit-per-second range, the industry has started adopting the Ethernet networks as a viable alternative, not only because of their lower cost. This paper presents an open-system approach in which protective hardware equipment is designed to work in a clustered environment, sharing resources, data, and diagnostic functions with similar units. The Ethernet network, being capable to accommodate transparently a wide range of protocols, is used to connect the protective hardware. A model was developed for the Ethernet network to be incorporated into the power system simulation. The characteristics required from a digital relaying algorithm to be able to work with signal samples sent across data packets based networks are described in this paper. The proposed solution is implemented using a modified adaptive least-square-error algorithm and tested on a protection system that was integrated into the power system model.