saved to the local database.Up to 12 lists can be pre- tems (WSDS)for access via Internet,"IEEE Trans.Power Syst,pp.206- set by the operator.The active list is determined by 212.May2000. the SCADA system administrator as well.Through this ODBC Web site.Available:http://www.microsoft.com/data/odbc. display,an operator can move a specific load up or down manually as well as add or remove a load from Biographies the list. Bin Qiu is a Ph.D.candidate of Virginia Tech.He received an M.S.in electrical engineering from Xi'an Jiaotong University,China,and an When an event occurs,messages are sent to two M.S.in electrical engineering from Nanyang Technical University,Singa- displays.Common system messages are sent to the pore.He worked in Power Automation Pte.,Ltd,a joint venture alarm list for display.The event list is used for warn- between Singapore Power and Siemens,as a network and software ing or urgent messages.In the meantime,common engineer.His interests include power system automation and comput- er and network applications in the power systems.He may be reached messages are saved to log file and events saved to the by e-mail,qiubin@vt.edu. database for the historical data retrieval.Figure 7 Yilu Liu is an associate professor at Virginia Tech.Her main shows the event list display. research interests are Internet and IT applications related to power system monitoring and control.She may be reached by e-mail, yilu@vt.edu. Open to the Future Eng Kiat Chan is managing director of Power Automation Pte,Ltd, Power system communication internetworking,such Singapore,and may be reached by e-mail,chanek@pa.cpm.sg. as the interconnection of multiple independent utility Lawrence Cao is a senior engineer of Foxboro Australia Pty Ltd.He received his Ph.D.from Sydney University,Australia.He is currently systems,has become the norm in new SCADA systems. working on n EMS project as a software team leader.He may be With rapid development of broadband techniques reached by e-mail,ljcao@foxboro.com.au. such as giga/tera bps fiberoptic and quality of service (QoS),LAN-based load shedding can be extended to large complex systems to per- form a certain degree of WAN-based control Lood Shedding Scquenoe and protection functions,such as load shed- CB St IED 5t DIFNr DIF Status Load( No 1 SS 146.6KV29KM.N/A 1方3 DisconnectD...040 ding and emergency area separation. Acknowledgment SS-2666KVTR-26_ A 470 SS-316.6KV73PM. 200 This project was implemented and commissioned in Power Ha SS-316.6KV73PM. 1042 200 No933316.6KV13PM- NA 10482 Disconnect/D... Automation Pte.Ltd.The authors wish to thank all col- 200 A N 2 leagues involved in the project for their hard work and No. A 10590 cooperation. 0000 D. For Further Reading B K.Rajamani and U.K.Hambarde,"Islanding and load shed- GTG1 GTG2 GTG3 GTG4 GTG5 COMI Listening ding schemes for captive power plant,"IEEE Trans.Power A N/A NA N/A N/A COM Dennet rl Delivery,vol.14.pp.805-809,Jul.1999. C.Concordia,L.H.Fink,and Geroge Poullikkas,"Load shedding on an isolated system,"IEEE Trans.Power Syst,vol. 10,pp.1467-1472,Aug.1995. Figure 6.LSC load shedding main screen O.Moya,"Power system computer controlled load shedding,"Electric Power System Research,pp.165-171, April 1996. y图回到■ G.S.Grewal and J.W.Konowalec,"Optimization of load shedding sheme in an integrated process plant,"IEEE Trans Event List Continue from Previous Page Pag2at27 Ind.Appl,vol.35,Jul./Aug.1999. 08 Jun 18:4603 [Real LSC]Open Log Fie [e:qiubinprogramvrainerVoadshedLog Eventl L.L.Peterson,et al.,Computer Network:A System 08 Jun 18:4603 [Real LSC]Open Alarm Log File [e:qiubin'vrprogramraineroadshed Logv Approach,San Mateo,CA:Morgan Kaufmann,2000. 184600 A.Berson,Client/Server Architecture,New York,NY: McGraw Hill,1997. Jun 184604 (Real ELCS]S r2 Socket can not be set Jun 18:4604 [Real DIF]LSC Socket (DIF100)Created on LAN 1 D.Guilfoyle,E.Connolly,"Distributed SCADA systems Jun 18:4604 [Real DIF]LSC Socket (DIF105)Created on LAN 1 for electricity distribution control,"Power Technology Int, Jun 18:4604 [Real DIF]LSC Socket (DIF43)Created on LAN 1 Last Page pp.169-172,1994. n 18:4604 IFeal DiFl Net Page M.Adamiak,et al.,"The role of utility communication in a deregulated environment,"in Proc.Hawai Int.Conf.Syst. Jun 18:4604 (Real DiF]LSC Socket (DiF73)Created on LAN 1 Previous Page Jun 18:4604 [Real DIF]LSC Socket (DIF35)Created on LAN 1 Sciences,,Maui,Hawii,Jan.1999. Jun 18:4604 [Real DIF]LSC Socket (DIF38)Created on LAN 1 First Page M.J.Menz and B.Payne,"Servers in SCADA applica- tions,"IEEE Trans.Ind.Appl,pp.1295-1299.Sept.1997. "Test methodologies,setup,and result documenta- LSC Socket (D3C, LAN 1 Last Page Hlelp tion for EPRI sponsored benchmark of Ethernet for protection control."Available:ftp://sisconet.com/epri/ benchmrk/ethernet.zip. E BEALAOMAUE下U B.Qiu and H.B.Gooi,"Internet-based SCADA display sys- Figure 7.LSC event list screen Juy200143saved to the local database. Up to 12 lists can be pre￾set by the operator. The active list is determined by the SCADA system administrator as well. Through this display, an operator can move a specific load up or down manually as well as add or remove a load from the list. When an event occurs, messages are sent to two displays. Common system messages are sent to the alarm list for display. The event list is used for warn￾ing or urgent messages. In the meantime, common messages are saved to log file and events saved to the database for the historical data retrieval. Figure 7 shows the event list display. Open to the Future Power system communication internetworking, such as the interconnection of multiple independent utility systems, has become the norm in new SCADA systems. With rapid development of broadband techniques such as giga/tera bps fiberoptic and quality of service (QoS), LAN-based load shedding can be extended to large complex systems to per￾form a certain degree of WAN-based control and protection functions, such as load shed￾ding and emergency area separation. Acknowledgment This project was implemented and commissioned in Power Automation Pte. Ltd. The authors wish to thank all col￾leagues involved in the project for their hard work and cooperation. For Further Reading K. Rajamani and U.K. Hambarde, “Islanding and load shed￾ding schemes for captive power plant,” IEEE Trans. Power Delivery, vol. 14, pp. 805-809, Jul. 1999. C. Concordia, L.H. Fink, and Geroge Poullikkas, “Load shedding on an isolated system,” IEEE Trans. Power Syst., vol. 10, pp. 1467-1472, Aug. 1995. O. Moya, “Power system computer controlled load shedding,” Electric Power System Research, pp. 165-171, April 1996. G.S. Grewal and J.W. Konowalec, “Optimization of load shedding sheme in an integrated process plant,” IEEE Trans. Ind. Appl., vol. 35, Jul./Aug. 1999. L.L. Peterson, et al., Computer Network: A System Approach, San Mateo, CA: Morgan Kaufmann, 2000. A. Berson, Client/Server Architecture, New York, NY: McGraw Hill, 1997. D. Guilfoyle, E. Connolly, “Distributed SCADA systems for electricity distribution control,” Power Technology Int., pp. 169-172, 1994. M. Adamiak, et al., “The role of utility communication in a deregulated environment,” in Proc. Hawai Int. Conf. Syst. Sciences, , Maui, Hawii, Jan. 1999. M.J. Menz and B. Payne, “Servers in SCADA applica￾tions,” IEEE Trans. Ind. Appl, pp. 1295-1299, Sept. 1997. “Test methodologies, setup, and result documenta￾tion for EPRI sponsored benchmark of Ethernet for protection control.” Available: ftp://sisconet.com/epri/ benchmrk/ethernet.zip. B. Qiu and H.B. Gooi, “Internet-based SCADA display sys￾tems (WSDS) for access via Internet,” IEEE Trans. Power Syst., pp. 206- 212, May 2000. ODBC Web site. Available: http://www.microsoft.com/data/odbc. Biographies Bin Qiu is a Ph.D. candidate of Virginia Tech. He received an M.S. in electrical engineering from Xi’an Jiaotong University, China, and an M.S. in electrical engineering from Nanyang Technical University, Singa￾pore. He worked in Power Automation Pte., Ltd, a joint venture between Singapore Power and Siemens, as a network and software engineer. His interests include power system automation and comput￾er and network applications in the power systems. He may be reached by e-mail, qiubin@vt.edu. Yilu Liu is an associate professor at Virginia Tech. Her main research interests are Internet and IT applications related to power system monitoring and control. She may be reached by e-mail, yilu@vt.edu. Eng Kiat Chan is managing director of Power Automation Pte, Ltd, Singapore, and may be reached by e-mail, chanek@pa.cpm.sg. Lawrence Cao is a senior engineer of Foxboro Australia Pty Ltd. He received his Ph.D. from Sydney University, Australia. He is currently working on n EMS project as a software team leader. He may be reached by e-mail, ljcao@foxboro.com.au. Figure 6. LSC load shedding main screen Figure 7. LSC event list screen July 2001 43