Copyright 0 IFAC Control of Power Systems and Power Plants, Beijing, China, 1997
THE COMPREHENSIVE DISPATCH AUIDMATION PROJECT OF BEIJING POWER SYSTEM AND THE INTEGRATED EMS SD- 60CME Z. Jin, J. Liu, Y. Wang, X. Lu, S. Mao Nanjing Automation Research Institute (NARI) China B. Sbu, G. Zbao Beijing Electric Power Bureau (BEPB) China
Abstract The traditional EMS and DMS are in fact dispatcher - oriented. The engineers in other departments such as scheduling and planning, system analysis, protective relay, etc. work with their own independent computer tools developed by different compaDies. The heterogeneous DB structure and display management tools make the system maintenance very diftiaJIt. In addition, due to the uncompletely comistent power system 1IlOdeb, the comparison and analysis of their calculated results also become difficult. The unified support software platfonn, consistent power system model, coordination and reasonable distribution of functions are expected. To extend the EMS/ DMS to a comprehensive .automation management system used by all departments of dispatch center is a feasible way. Beijing power system is the largest district system in China • NARI has taken the job of construction of the comprehensive automation system for Beijing Electric -Power Bureau. This paper introduces the system system planning, designing, developing and project scbeduIing. Copyright© 1998 IFAC Keywords: Energy Management System
(EMS), Distribution Management System
(DMS), distributed computer control system
1. INTRODUCfION
their control centers in accordance with this concept, (Tamotsu, 1991; Hong, et al., 1992) so did in China. (Jin, et al., 1995). In view of this trend and in conjugation with the self experience of developing EMS / DMS , NARI made a decision to develop this integrated EMSIDMS in advance to meet the potential requirement of Chinese utilities. Question was how to determine the specification of this new system before development and where to run this system after completing the development. Because this was a big and sopbysticated system engineering, it was impossible to succesefuIIy complete this new system
In the nineties, along with the development of the computer technique, and network CODDOunication technique, it is possible to distnbute the functions of EMS / DMS from the traditional mainframe to a distributed Computer Control system. Then the trend of EMS/ DMS evolution cbaoges from The supervisory tool only for dispatchers to the integrated system for the stafI's of whole dispatching center to raise its efficiency •
Some utilities have planned to design or develop
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coDects the data from more than ten substations. To increase the communication reliability, dual channe~ are adopted, one for transmiting the data from SOC to the district control center with the R1U protocol directly, another one for transmiting the data via suburb control centers to the district control center with X. 2S. The data exchange between fourteen county control centers and the district control center are via WAN with X. 2S. The data exchange between the district control center and the control center of North China power pool is via WAN with DDCMP. The data communication link of BEPB is shown in fig.2.
without in cooporation with a big utility. NARI made a cooperation with largest distribution utility BEPB(Beijing Electric Power Bureau) in China to make the comprehensive automation plan of the new control center of BEPB from 1992. Abnost in the same time, NARI began the development of the integrated EMS/ DMS Styled. SD - 6000. The first system was completed and delivered to a meditnn district power system zmo as an experiment system in October 1994. (Jin, et al., 1996) A part of the integrated EMS/ DMS system with new version SD - 6000E is to be delivered to BEPB in December of 1996. The whole project will be completed in 1998. In this paper, the comprehensive antomation plan of control center of BEPB and the design of SD - 6000E are introduced •
2. COMPREHENSIVE AUfOMATION PLAN OF CONTROL CENTER OF BEPB 2. 1 Brief introduction of Beijing power system
Beijing power system is the Iargest district power It covers 16, 900 square kilometers. There are more than 250 substations with the voltage of SOOKV, 22OKV, llOKV , 35KV, 10KV in Beijing power system now, and plan to increase to about 300 in 2000. There are more than ten subsidiary control centers( CC) , such as city proper CC, suburb CC, and county CC. The hierarchical dispatch organization of BEPB is shown in fig. 1. system in China.
Fig.2. The data communication link of BEPB 2. 3 Brief introduction of the functional design of the
master station of BEPB In fact, SO called. comprehensive automation of the district control center is based on the comprehensive function of the master station. The feature of Beijing power system is that it includes the transmission system and distribution system , and all information needed by the city distribution control center will be collected by the same data acquisition system of district control center (DCC), so both the functions of EMS and the functions of DMS sbould be planned , and according to the comprehensive automation requirements the functions for all sections of DCC based on data sharing should be planned.
To North China power control center
Fig .1. The hierarchical dispatch organization of BEPB 2. 2 Data coTTl1TUl1l.icatin of BEPB
2.3.1 The Functions for Dispatchers .
According to the plan , all the data of the substations with llOKV and 35KV are to be transmitted to the district control center via substation operating centers (SOC) • Each SOC
SCADA for the dispatchers of the district control center and the city proper control center The data transmiscrions are composed. of different ways
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C. The protective relay management including the short circuit calcuJation;, D. The statistics and analysis of the historical data stored in the commercial database for power syetem planning; . , E. Geographic Information System(GIS)
such as to collect the data from RID via front end with RID protocols, to collect the data from distn"bution control centers via WAN equipmeut with X.25, to collect the data from feeder equipment via radio system ere. The SCADA should meet all these requirements •.
This function is used either for the dispatcher to monitor the situation of power system. in connection with the geographical map , or for dispatch manage - ment staff to plan the new feeder and distribution equipment. It is neceswy to combine the real time data with GIS database to form the SCADAIAMlFM/GIS function.,
Following Power application software (PAS) main points should be considered in PAS plan of BEPB: (a) Beijing power system is composed of nine sub - power systems. Each subsystem includes
several substatiom. Bul the. configuration of these 2.4 Plan of master station configuration
subsysterm may be changed according to the daily schedule or the temporary decision of the dispatchers. This factor may inftuence the result of calculation .. (b) There are two parallel transmi9rion rings with 220KV around the city, the contingency analysis have to consider the principle of n - 2 instead of n-1. (c) Many T type transmimon lines exist, and the distance between two T nodes may be very short. This factor should be considered in power system calculatiom . . (d) DTS. Because there are a lot of subsidiaries existed, the of DTS of BEPB should meet the requirements not only for the dispatchers of nee, but also for the dispatchers of all subsidiary control centers as well. (e) The on line operational sequence card management. Because the power system configuration is very complicated, this function should be expert system based •. (f) Multi - Screen Vedio Graphic Wall Function, The multi - screen vedio graphic wall with ten projectors has been planned instead of the traditional mimic board. It is necessary to develop the interface between the multi - screen vedio graphic system and EMS so as to operate the graphic wall controllor via EMS workstatiom., (g) Other functions such as voltage and VAR control , inteDegent telephone notifying.
To meet the functional requirements mentioned above, the master station configuration should be designed in accordance with following speification:
A. All the computers should be the advanced workstations or servers with 64 bits. The number of computers should be no less than twenty. , B. The front end computer should collect the data of no less than 300 RIDs with point to point link each • . C. All the computers and front end should be connected via the dual LANs. , D. The number of the ports of interface to WAN (wide area networldsbould be no less than 24. , According to these requirements NARI began 'to design the new integrated EMSIDMS system SD 6000E with the system configuration as fig. 3.
Fig.3. Sytem configuration Note: T - - Trainee, I1NS - -Instructor!Network simulation OM - - Operation mode, SM - - Schedule and Maintenance PR - - Protective Relay Xt - - X tenninal
2.3.2 Functions for dispatch management ,
These functiom are first planned in 0Jinese utility. They are: , A. The operational mode study;, B. The schedule and maintenance plan study;,
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PC X t - - PC X terminal. PC NM - PC Network management TS - - Terminal server MVGS - - Multi-&.reen Vedio Graphic System PRT - - Printers HC - - .Hard Copiers 3. DESIGN OF TIlE INTEGRATED EMSI DMS wrm TIlE UNIFIED SUPPORT SOFIWARE PLATFORM
SD - 6000E is designed as an open and distributed
Fig.4. The software architecture of SD - 6000E
system. note: PR - - Protection relay TSA - - 'I'ramient stability analysis SIM - - Schedule and maintenance. OIM - - Operation mode. SUPACK - The name of NARI developed support software platform.
3. 1 The HI W platform and system software tksign
In view of the trend of RISC tecbnique and after studying the latest docmnentation, DEC ALPHA Series computers with 64-bits are selected for application nodes. According to the commDnication 110 requirement, the MOTOROLA Delta 4520 with large amount of 110 ports (up to 320 ports) are selected as the front end nodes. All the nodes are coonected via dual rAN and dual HUB • .
In line with the international standards and de facto standard, the POSIX compliant UNIX operating system, X - WindowI Motif graphic interface standard, TCPI JP communication standard are selected. 3. 2 Design of support software platform in distribution environment The sopport software platform developed by NARI includes the following sub;ystems: database . management subsystem; graphic creation and MMI subsystem; network communication subsystem , task management subsystem, operation authority management subsystem, report management subsystem, and system operation management subsystem. The relation among the system software, support software platform and application software of integrated EMSIDMS is shown in fig.4.
application distribution, therefore every subsystem should have distribution features respectively. SD - 6000E uses object oriented technique to meet this requirement. An AOB (Application Object Based) concept is introduced. AOB encloses the application software with its real time data bases (RIDB) and its MMI. RIDB for power system application is power system - oriented and specially designed to adopt the hierarchical structure of power system and dispatch organizatiom. One DB definition can generate a lot of DB entities for different AOB to enclose it. The attributions of RIDB is inheritable. AOB is the basis of distribution environment of SD 6OOOE. The distribution functions of all sub;ystems mentioned above depend upon it.
3.2.1 Distributed DB management subsystem . Basic function There are two kinds of DB in this project: historical DB (HDB) and real time DB (RIDB) • The first one is relational and managed by COIIlIIleI"Cial DBMS (SYBASE) • The structure of RIDB is combined hierarchical and relational. The RIDB residing in memory is
managed by RIDBMS which provides a series of graphical interactive tools for defining, creation, manipulation and maintenance of RIDB. Its convenien~ and frienc:lliness seem to be at least the same as of the conventional general graphical
Each of these subsystems has its advanced inherent functions. The most ·important is that they jointly constitute a distribution environment to support
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displays of all AOB. Directories are maintained automatically. User can call any one of displays no matter which node its definition file and linked DB locate on •
interactive tools of commercial RDBMS and its
speed is much faster. Specially designed tools are
natureUy easier for use, because of simple. Thanks for independence of RlDB from commercial RDB, SD - 6000 E can always work
3.2.3 Distributed task management subsystem
without the commercial DBMS • RlDBMS also provides a set of a~ routines and SQL commands for API (Application Program Interface) • The SQL is also used for data exchange with other kinds of commercial DBMS like ORACLE for IIDB. The client - server and peer to peer ~ mode and case saving and retrieving are offered by RIDBMS •.
In system openration AOB is taken as a set of tasks to be dispatched •. A friendly dispatching table display is used to set the task operation conditions and operation cycle time. Each node holdc; the dispatching tables of all nodes. An AOB can be assigned to any node. The communication between tasks running on dift'erent nodes is transparent. A task can be triggered to run by a task on other node.
Distribution fmtction Different RlDBs can be distributed on dift'erent nodes of the LAN. One original RIDB can be duplicated by broadcasting to any nmnber of nodes appointed. CorNstency of them is ensured. This Producer - Consumer method is very useful for SCADA DB which are needed by many application nodes. Any application software can a~ DB wherever the DB resides. This is transparent for user. 3.2.2
Distributed
display
3.2.4
Distributed subsystan
report
management
Two report edition tools are available. One uses ASCll symbols to edit any format of reports normalized or unnormaliU!d and output them using ASCll code. The second tool uses full graphic symbols to build reports on which tables and pictures can be mixed together and output using vector or bit map •.
management
subsystem.
Basic function This subsystem is based on object - oriented technique. A three-in-one tool kit is designed to build RIDB and network topology in the procedure of editing one line diagram. The same set of one line diagrams of stations and
This subsystem allows any nodes to output reports on the ~ printers in LAN no matter where .they are connected to •The report integrity is
ensured.
network can be used for SCADA, PAS as well as DTS applications. A rubber band tool is designed to conveniently move the stations and power lines on the network one line diagram. in vertical and
3.2.5 DistnDuted operation authority management subsystem
horizontal directions for reallocation and new station insertion.
In the distribution environment any body can make one workstation as a virtual tenninal of other workstation by nmote log in, so 3S!rigning operation authority according to operation keyboards or several work duties is no longer suitable. In SD - 6000 E authority is given according to user's name and security codes. The basic operation object is AOB. Authority for all users is duplicated into every computer. This subsystem can guarantee against occurance of unauthorized operation in distl'lDution enviromnent.
Beside the decIutter function a multi - plane overlap function is also provided, Which planes need to be overlaped together can be selected by user on -line. This method creates the conditions for MWmbling displays overlaped by network dynamic diagram with geographic information map or satellite meterological map. Distribution funtion The display detinition files and AOB locate on the same node. The ~B to which the display data are linked can reside on any nodes. Each node has cIasmied directories of
3.2.6 Distributed system operation management subsystem
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remaining functions including GIS etc. are to be completed in 1998. Later on, the distribution automation like feeder control will be plaImed and developed.
Every computer node should lmow at any time the operation states of other nodes in the distribution enviromnent. When a computer changes to on line operation state, it can get all kinds of global directories, tables and other infonnation used for initialization from SCADA server. Any important computer on the LAN can be organized as dual redundant pair. Any online computer may communicate with the primary one of this pair whenever switch over happens.
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3.2.7 Distributed communication management subsystem
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In this project, some computers are connected with dual Ethernets and some of them (X tenninal) with single Ethemet. In adition it should be considered not only the point to point, but also the broadcasting communication. These make the routing mechanism very complex. 1be po!Imole solution for SO - 6000 E is to take each Ethemet interface as a routing unit and to duplicate routing table to every computer. For application software only one node ID is provided. The relation between application software and this subsystem is client - server. This subsystem is also designed to support all other subsystems mentioned above.
Fig. 5. The function configuration for BEPB project
REFERENCE Tamotsu Minakawa. Scheme and Design for Advanced. Energy Control Centers. IEEE
Power Engineering Review. Febrary 1991. Hong H. W., Carl f. Imparato David L. Becker, James H. Integrated Support Systems for
Electric Utility Operations. IEEE CompuJer Application in Power. January, 1992. Jin, Z., Liu, J •• TIle Trend in Development of
4.APPLICATION SOFIWARE AND PROJECf
MANAGEMENT
EMS/DMS for Control Centers in the 90' S.
4. 1 Appli.catWn software development
AuJo11llllion of Electric Power Systems. June, 1995. Jin, Z., Liu, J., Lu, X., and Sbi, Z •• The Open
TIle development of all application software and the SQL based interface to RIDB are in accordance with the functional requirements. Some third party softwares are used, They are the commercial relational database management system SYBASE and the GIS ARC/INFO. 1be system function configuration is shown in fig. 5.
4.2 Project
and Distributed EMS SO - 6000 with Unique Support
Software
Platefonn
and
its
ZIBO Power Syste. AuJo11llllion of ·Electric Power Systems. October, 1996. Application
~
This comprehensive project is to be completed in three stages:
TIle SCADA system including multi - screen video graphic system have been delivered in December 1996. 1be PAS, DTS and other functions are to be completed in 1997.10 third stage, all the
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