外文翻译--发电厂电气系统综合自动化

1、发电厂电气系统综合自动化)摘 要：针对电厂电气系统自动化水平相对落后的状态，本文分析了在电厂电气系统中采用综合自动化技术的可行性，必要性及几个关键问题，提出了利用现场总线技术的新思路，并给出了具体的实施方案。关键词：发电厂电气系统，现场总控线制系统，集散控制系统，综合自动化综合自动化系统已经被应用于变电站系统中，并且分散分配技术也被广泛地用于综合自动化系统中。与集中的技术相比较这种技术有许多的优点，比如：它有简单和柔韧的结构，高的可靠性，方便的安装和较低的成本。然而，综合自动化技术并没有广泛的用于发电厂电气系统中。电力系统中起保护作用的继电器和其他安全设备处于半自动运行状态，并没有实现综合自动

2、化。因此，管理和维持高水平的工作就落后了。后来，越来越多的电厂特别是那些新建的电厂热忠于电气综合自动化系统而不是传统的集散控制系统。 这篇论文分析的是发电厂电气系统的现状以及提出了基于微型计算机技术的发电厂电气系统综合自动化的理想应用程序，并给出了具体实现方案。 1 发电厂电气系统的现状这篇论文讨论的是电气系统，主要涉及到保护、测量和二次系统的自动控制装置。主保护包括了发电机保护，主变压器保护和备用变压器保护。自动控制装置包括了自动调压装置，自动跳闸装置，故障波动曲线记录装置和自动同步系统。6千伏后备保护包括电动机高压综合保护装置，后备变压器保护装置和母线保护装置，等等。400伏低压保护包括电

3、动机低压智能保护，断路器智能保护，等等。上述这些都是属于电气系统的范畴。而普通系统如煤处理系统，灰处理系统，汽水系统并不包括在电气系统内。电气系统与发热系统相比其电力设备所控制对象较少，操作频率较低的特性。电力设备具有很高的可靠性和迅速的动作时间。单个电力设备具有较高的技术水平。目前16位或32位的单片机和大规模可编程逻辑芯片被用来建立系统，ac抽样和数字信号程序技术也被广泛采用。集散控制系统被广泛的应用于电厂中，它能完成基本的操作和控制功能。集散控制系统主要关系到汽水系统同时少量涉及电气系统。传统上，控制和信号在集散控制系统和电力系统之间的交换是通过“硬式电缆”来实现的，这样一种联络模态需要

4、许多电缆，因此费用很高。由于信息交换受到费用的限制，因此它不可能完成复杂的操作或者完成深入的应用。因为集散控制系统是发电厂中最重要的系统因此，集散控制系统和电气系统的联系是必然的。许多设计方案关心的是集散控制系统也电力系统之间表现出来的联系，但是他们大部分都是基于“硬式电缆”的。这项新技术是值得被用于这个领域的。2 电力系统综合自动化可行性分析电气系统自动化的进步是建立在综合自动化和现场总线或以太网络工艺学基础之上的。以微型计算机为基础的保护和自动化设备被广泛地应用在电厂电气系统中。测量，逻辑判断，动作记录和人-机界面的功能都可以由软件来完成。并且，所有这些设备都具有通信界面，能够和主系统或其

5、他系统之间通过现场总线进行信息交换。现场总线控制技术目前已被广泛用于工业和电力系统中，并且这项技术越来越受到重视。现场总线控制系统的通信速率，通信距离，抗干扰能力都有了极大的改善。其许多标准也被制定，如西门子公司的profibus和abb公司的ff标准等。这些标准都是很有影响的现场总线技术，而且在工业自动化领域有广泛的应用。现如今工业以太网络变成了新的热点。以微型计算机为基础的电气系统，现场总线系统或者以太网络技术的应用程序和通信功能由给发电厂综合自动化提供支持的集散控制系统提供。3 电力系统综合自动化的实现途径电力系统的综合自动化先要通过现场总线将用于保护的继电器和自动装置连接起来，然后把他

6、们连接到集散控制系统再通过通信设备与可能的电站相连。电站执行一个比如测量或者维护的程序时，这种基本的操作功能由集散控制系统来完成。随着技术的发展，这些控制功能也可以由通讯手段来实现。建立电力系统综合自动化有两个主要的问题，一是如何建立电力系统的网络，另一个是如何使电力系统与集散控制系统相连。现场总线标准是建立网络的主要问题。由于保护和自动装置由不同的厂家生产，所以其物理上的层和通信协议可能会有所差异，这样就使得设备之间不可能被简单的联系起来。因为要统一现场总线系统很困难，解决这一问题的一个方法是把电力系统分割成一些子系统。根据电力系统的功能这些子系统被分为6千伏子系统，400伏子系统，变压器保

7、护子系统和avr子系统等等。每一个子系统支持一种相同的现场总线标准。举例来说，线路保护、电动机保护、变压器保护在6千伏电压等级上必须支持同一个标准。400伏系统的保护或者智能断路器要用同一种标准。发电机变压器保护和avr应该用同一标准。这些子系统可以单独地和集散控制系统相连，或者在连接了一种特别的通信控制器之后再与集散控制系统相连。关于电力系统和集散控制系统之间的连接有以下几方面的内容：连接模式：电气系统与集散控制系统之间的连接有两中途径。一种是dpu（数据程序单位）集散控制系统的基极。另一种是由以太网络。在dpu模式中集散控制系统必须提供一种或者几种通信通道，这些通道使用rs485和modb

8、us协议。在以太网络模式中，集散控制系统通过传输控制协议与电力系统相连。控制问题：理想的控制模式是所有的检测和控制功能都通过集散控制系统的显示屏来完成。但是目前由于电的互锁和可靠性问题，集散控制系统仍然需要用到电缆。一般系统：发电机和集散控制系统都能检测到一般系统的数据。一般控制系统的控制功能能够被发电机和集散控制系统识别。但是只有集散控制系统才能一直识别一般系统的控制，而且这些控制还可以在两个集散控制系统之间转换。集散控制系统和电气系统之间的信息交换：这些信息包括，测量信息，开关状态, 动作信息，设定故障点，故障诊断，控制命令等等。实际上集散控制系统只与这些数据的一部分有关，其他的数据只能用

9、于更先进的电程序。不像变电站的综合自动化，电力系统综合自动化有两个主题。一个是集散控制系统另一个是电站。电站系统能完成以下一些功能。数据获得和监测：在电路图和其他图片的协助下，它能监测到附加系统的所有参数。自动仪表阅读：在大多数电站中，附加系统的仪表阅读靠人工完成。一些有能力的电厂用一种特殊的读表系统，建立特殊的网络来记录耗电量。凭借电力自动化系统，电站能够完成自动读表的所有功能。设备管理: 它包括,计算、保护记录、自动装置和时时功能（比如运行时间记录）设定管理点：这个功能能够完成远动功能，并且时时自动核对监控。故障信息管理：它可以完成，动作报警，故障取消，故障重复，故障记录和分析。故障诊断：

10、这项功能可以诊断出电动机的状态，比如转轴断裂和电动机停机。总之，其他的一些应用比如发电机的监测和稳态的系统分析都包含在电站系统中。4 电力系统综合自动化方案系统框价的图形如图1和图2所示，每个图形显示了一台发电机以及与它对应的自动化系统。在图1中,电气系统被区分为四个部份#1，6千伏子系统#2，400伏子系统；6千伏通用子系统和400伏通用子系统。所有的子系统都由dpu与集散控制系统相连。通信控制器必须被设计来可以兼容不同的通信协议。如果所有的通信控制器都用同样的通信协议，那么这种控制器就有可能被取消。对于典型的发电厂设计，一个系统中有两台发电机，仅仅有两个子系统（#2，6千伏子系统和#2，4

11、00伏子系统）必须加到#2发电机上。在图1中现场总线层用不同的网络拓扑结构。我们推荐6千伏子系统用环行网络，而400伏子系统用辐射型网络。如果我们分离dpu界面，并且由以台网络连接集散控制系统，那么通信模式也会相应的转变成以太通信模式。图2显示了dpu-以太网络混合通信模式。在这种模式下，互锁的电动机被集散控制系统-dpu所控制，其他的设备则通过以太网与集散控制系统相连。图1图25 总 结采用电力系统综合自动化是提高电厂自动化水平的趋势，特别是改善电厂的管理水平。这将减少投资提高可靠性，微机保护，成熟的通信和现场总线技术是电气系统综合自动化的技术保证。这篇论文提出了电气系统综合自动化两个系统的

12、问题。但是与集散控制系统之间的连接，现场总线的标准，通信网络的结构还仍然处于研究和关注中。inte grate d auto matio n of power pla nt electrical syste mguo wei1(1(2abstract:schemes.key words:integrated automation technology has been appliedin power system substations , and decentralized anddistributed technology 1 is widely used in integratedaut

13、omationsystem.comparedtothecentralizedtechnology , this technology has many advantages suchas simple and flexible structure , high reliability ,convenient installation and low cost of maintenance.however , integrated automation technology hasnot been widely used in power plant electrical system.prot

14、ective relay and security devices of electricalsystem run in a self2governed state , which haventformed an integrated electrical automation system.therefore , the managing and maintaining level hangbehind.latterly , more and more power plants ,especially those newly constructed are interested in the

15、automation of power plant electrical system and itsrelationship with traditional distributed control system(dcs) .this paper analyzes the actuality of power plantelectrical system , brings out a new ideal of applicationofmicrocomputer2basedintegratedautomationtechnology to power plant electrical sys

16、tem , and givesthe material project .wang li2department of electrical engineering , southeast university , nanjing 210096 , china)nanjing 55th research institute , nanjing 210016 , china)power plant electrical system , fieldbus control system , dcs , integrated automationreceived 2001207226.the proj

17、ect supported by seu technological foundation ( xj001633) .born in 1970 , male , associate professor.actual ity of po wer plant electrical sys2temthe electrical system discussed in this paper ismainly referred tothe protection ,measurement ,control and automatic devices of secondary system.main prot

18、ection devices include generator protection ,main transformer protectionandstart up/ stand bytransformer protection.automaticdevices includeantomatic regulator voltage (avr) ,automatic transferswitch(ats) ,faultkymographandprotectionincludeshigh2voltagemotorlow2voltage system includes auto2low2volta

19、ge intelligentmotor protector ,breaker , dc system , etc 2 water system are not included.the characteristics of electrical system 3 operation frequency than thermalmicrocomputer and large2adopted.mainly on steam2electrical system.“hard cable”.exchange is limited on account of the cost .impossibletoa

20、ccomplishmorecomplexelectrical data.aiming at the comparatively laggard level of power plant electrical system automation , this paper analyzes thefeasibility ,necessity and some key points of the application of integrated automation technology to power plant electricalsystem. new idea using fieldbu

21、s control system technology is presented. this paper also gives the outline and detailed1antomaticsynchronization system (ass) . 6 kv auxiliary powerintegrativeprotection device , auxiliary transformer integrativeprotection device , feeder protection device , etc. 400 vchangeover device ,intelligent

22、. all these belong to theelectrical system. the common systems such as coalhandling system , ash handling system and chemicalare thatelectrical equipments have less control objects , lowersystem devices.electrical devices have high reliability and swift actiontime. the technology level of individual

23、 electricaldevice is high. presently , 16 or 32 bit single2chipscale programmable logic chipare used to build embedded system. technologies ofac sampling and digital signal process are also widelydcs is widely used in power plants , and it fulfillsbasic operation and control functions. dcs concernsb

24、oiler system meanwhile little ontraditionally , control and signalexchange between dcs and electrical system is throughthis connection mode needs manycables , and the cost is high. besides , the informationit iselectricoperation management or achieve deep application ofsince dcs is the most importan

25、t system in power设计巴巴工作室222guo wei , and wang liplants , the connection of electrical system to dcssystem is out of question. many schemes concernedabout the connection to the dcs have been presented ,but most of them are based on“hard cable”. it is worthconsidering that new technology can be used t

26、o thisfield.2 fea sibility analysis of electrical systemintegrated automationthe improvement of electrical system automationis based on integrated automation and fieldbus orindustrial ethernet technology.microcomputer2based protection and automationdevices are widely used in power plant electricalsy

27、stem. the measure , logic judge , action , record andman2machine interface function canbedonebysoftware. moreover , all these devices have communi2cation interface , they can exchange information withmaster system or with each other through fieldbus.fieldbus technology has been widely used inindustr

28、y and electric power field , and it has been paidmoreandmoreattention.thetechnologyincommunicationrate ,communicationdistanceandanti2jamming capability has been improved. many sortsof standards have been formed , such as profibusadvocated by siemens , ff by abb , can originatedfrom automobile indust

29、ry and lonworks brought forwardby echelon company. they are all influential fieldbustechnology and applied in industry automation area 4 .recently , industrial ethernet network becomes newhotspot .the application of microcomputer2based devices ofelectricalsystem , fieldbus or industrialethernettechn

30、ology and communication capability provided bydcs system bring powerful support for the integratedautomation of power plant electrical system.3 real ization of integrated automation inelectrical systemelectrical system integrated automation is toconnect foregoing many protective relay and automation

31、devices by fieldbus and then connect them to dcssystem and (possible) electrical workstation throughcommunication devices.the electrical workstationimplements all the electrical application such asmonitoring and maintenance function , and the basiccontrol function is accomplished by dcs system using

32、“hard cable”. with the development of technology , thecontrol function can also be fulfilled by communi2cation.therearetwomainproblemsinbuildingintegrated electrical automation system. one is how tobuild the electrical system network ; the other is how toconnect electrical system with dcs.fieldbus s

33、tandard is the main problem in buildingthe network. due to the protection and automationdevices produced by different manufacturers , thephysical layer and communication protocol may bedifferent , so the devices cannot be connected simply.since it is difficult to unify the fieldbus standard ,one way

34、 to solve this problem is to divide electricalsystem into several subsystems.according to theelectrical system feature , the subsystem can be dividedinto 6 kv subsystem , 400 v subsystem , generator2transformer protection subsystem and avr subsystemetc.each subsystem supports thesame fieldbusstandar

35、d.for example , feeder protection , motorprotection , transformer protection on 6 kv bus mustsupport one kind of standard. protections of 400 vsystem or intelligent circuit breaker use the samestandard. generator transformer protection and avrcan have the same or different standards.thosesubsystemsc

36、anbeconnectedtodcssystemseparately , or they can connect to special commu2nication controller before being connected to dcs.as for the connection between electrical systemand dcs , there are several aspects. connect mode. the electrical system network canconnect dcs in two ways. one is by dpu (data

37、processunit) the base layer of dcs.the other is byethernet network. in dpu mode , dcs must provideone or several communication ports , mostly this portusing rs485 and modbus protocol .in ethernetmode , the electrical system can connect to dcs factorylayer using tcp/ ip. control problem. the ideal co

38、ntrol mode is thatall the monitoring and control function are fulfilled indcs using monitor. but currently , considering theelectrical interlock and reliability , the dcs controlfunction still uses“hard cable”.common system. both two generator units dcscan monitor the common system data. common syst

39、emcontrol function should be realized in both twogenerator units dcs. but only one dcs can control thecommon system at time , and the control can beswitched between two dcs. information exchanges between dcs and electricalsystem.theinformationincludesmeasurementinformation , switch state , meter inf

40、ormation , actioninformation , set point , fault diagnosis , time checkout ,integrated automation of power plant electrical system223control command and so on. in fact , the dcs concernsonly a part of these data , other data can be used forfurther electrical application.unlike substation integrated

41、automation , electri2cal system integrated automation have two masters. oneis dcs , the other is electrical workstation.theelectrical workstation system can achieve the followingfunctions.data acquisition and monitoring.with theassistance of electrical connection map and otherpictures , it can monit

42、or all electrical parameters ofauxlliary power.automatic meter reading.in most plants , themeter2reading of auxiliary system is completed manu2ally. some power plants use specific meter readingsystem , set up special network to record the powerconsumption.withelectricalautomationsystem ,electrical w

43、orkstation can implement all the functionsof meter2reading system.equipments management . it includes accounts ,files , maintainence records of protection and automaticequipment , and this function is online (such as therunning time record) . set point management . this function carries outremoteset

44、ting ,modifyingandonlineautomaticchecking of setting value.fault information management .this functionfulfills action alert , soe , fault recall , fault replay ,wave recording and analyzing.fault diagnosis. this function diagnoses motorstate such as sqirrelcage break and motor stop .in addition , ot

45、her applications , such as generatormonitoring and analyticalsystem ofsteady stateoperation 5 ,6 can be included in electrical workstation.4 project of electrical system integratedautomationthe model of system frame is shown in fig. 1 andfig. 2. each figure shows only one generator unit andcorrespon

46、ding electrical automation system.in fig. 1 , the electrical system is divided into fourparts : # 1 , 6 kv subsystem # 1 , 400 v subsystem ; 6kv common subsystem and 400 v common subsystem.all the subsystems connect to dcs by dpu.thecommunication controller must be designed to handledifferent commun

47、ication protocols. if all the devices un2fig. 1 sketch map of system structure 1dpu modefig. 2 sketch map of system structure 2dpu2ethernet hybrid mode224guo wei , and wang lider thecommunicationcontrollerusethesamecommunicationprotocol ,thecontrollercanbecancelled.fortypicalpower plantdesign ,twoge

48、nerator units with one common system , only twosubsystems ( # 2 , 6 kv subsystem and # 2 , 400 vsubsystem) must be added to the # 2 generator unit .in fig. 1 , fieldbus layer uses different networktopology. we recommend that 6 kv subsystem usesdual2net whereas the 400 v subsystem uses singlenetwork.

49、if we disconnect the dpu interface , and connectthe dcs by electrical ethernet , the communicationmode is changed to ethernet communication mode.fig. 2 shows the dpu2ethernet hybrid communi2cationmode.inthismode ,interlockedmotorbelonging to the same set is directly controlled by onedcs dpu. other devices connect