Wireless Power Monitoring and Control System
Contents
1. the requirement for cables 4 Also it will be much more reliable because it removes the possibility of a cable being severed or defective A wireless system should significantly reduce costs by eliminating any cable costs and reducing installation time 7 2 2 Design of Wireless Communication Units There are 4 main considerations in the design of the wireless units 1 Packaging 2 Safety 3 Power loss 4 Speed Of these Safety and power loss are the most important Packaging must be able to withstand heavy wind rain extreme heat and extreme cold Also it must be aesthetically pleasing In the event of maintenance it should be simple enough to open and quickly modify any hardware based operating parameters There should be an easy way to discontinue remote control of devices so that serviceman with no risk of anyone remotely activating the device may perform routine maintenance This is commonly called a supervisory switch and most new devices already have these Several older devices including most analog devices do not have any form of remote protection These devices will need an external supervisory switch built into the monitoring system All units should remain stable through a power loss This means that the user should not have to perform the installation procedure after each power loss Some parameters will have to be stored in some type of memory so that when power is restored they can simply return to o2. Department of Electrical amp Computer Engineering Requirements document for Wireless Power Monitoring and Control System Submitted to Professor Joseph Picone ECE 4512 Senior Design Department of Electrical And Computer Engineering Mississippi State University Mississippi State Mississippi 39759 April 24 2000 Submitted by Randall Hand rehi ece msstate edu Chris Taylor cati ece msstate edu Michelle Davis mdavis95 hotmail com Dontra Caldwell dic4 ra msstate edu Executive Summary Currently only large power utilities can use computerized systems to monitor and control substations and downstream devices These systems allow live reporting and control capabilities as well as automated switching capabilities in most cases Unfortunately these systems usually have an installed cost from several thousand dollars up to one million dollars or more 10 5 and require such exotic equipment such as fiber optic modems and land lease lines for dedicated communications 9 While these allow for a fast reliable system the price makes it prohibitive for smaller utilities and cooperatives 5 Our design will allow reporting and control capabilities but with a cost in the thirty five thousand dollar range and with a wireless implementation between the host amp location and the location center and individual devices 4 All this will be done while keeping latency at a minimum to make the new system respond nearly as quickl
3. ation Electric Power Research Institute 1982 Bodemann Leroy J The Pre Implementation Phase of the Gulf States Utilities Energy Management System 1982 Control of Power Systems pp 17 21 Ackerman William J Small Substation SCADA Solutions 1998 Rural Electric Power Conference pp C1 1 C1 7 Rudolph David L An Integrated Solution to Substation Automation 1998 Rural Electric Power Conference pp C2 1 C2 9 Orbcomm Global Data amp Messaging Quick Facts 21700 Atlantic Boulevard Dulles VA 1997 Scientific Atlanta Communications and Tracking Systems Scientific Atlanta Low Earth Orbit Fixed Site Communicator 3845 Pleasantdale Road AtlantaGA 1997 Scientific Atlanta East Mississippi Electric Power Association 4356 Communications Drive Norcross Georgia 1999 Sakata Albert T Smith Bradford E Microprocessor Based Substation Metering and Control System 1984 Control of Power System Conference pp 10 16 15 Wireless Mountain Laboratories Inc Unilink User s Manual 560 A Higuera San Luis Obispo CA 93401 Rev 990519 16 GE Harris COOPER 2179 DCA Functional Specification Doc A039 OFS WES Version 7 01 Figure 2 1 Equipment involved in the overall process Utility Equipment Communicator 306 ff Range
4. ed and trained technicians to monitor and control the systems at all times These features should make this system more appealing to smaller electric utilities that need automation technology but don t have the budget to accommodate larger systems or extra employees 5 Beyond this project the software and technology could easily be expanded to accommodate more services such as agriculture offshore oil rigs and any other application that involves machinery that could be remotely controlled or monitored via dry contacts Several other industries and businesses need inexpensive ways to monitor and control devices in remote locations such as breakers pumps and generators and this system would be ideal for these situations Also the technology could be further extended to decrease the latency with the satellite communications and the wireless communications system could be improved to allow longer range All of these would further increase the usefulness and capabilities of the system 1 Problem Large electric utilities frequently use automated systems to monitor and control devices in the field and in substations 1 _ These allow switching routines and minor maintenance to be performed in much shorter time than any human could accomplish by eliminating the time required to drive to and from the site They also save money by not requiring as many people to be on call 5 These systems reduce error downtime and costs by reducing the amount o
5. edgements We wish to thank East Mississippi Electric Power Association and Global Automation Systems for providing us with equipment for testing and supporting this project We also wish to thank Scientific Atlanta and OrbComm for provided us with satellite transponders and free airtime Finally we would also like to send out a great deal of appreciation to our advisor Dr Donohoe for all his time effort and guidance that he has provided to us in making this project a success 4 References 1 2 3 10 11 12 13 14 Marks John 1999 November December Substation Monitoring amp Diagnostics Electrical World pp 16 17 20 21 Cooper Power Systems 1999 January February Reliability vs Liability Electrical World pp 4 5 Marks John 1999 January February Use of Fiber Optic Cable Grows for T amp D Applications Electrical World pp 44 45 Rosi David Cerluean Technology Inc 1999 December Raising the Service Bar with Wireless Mobile Communication Electric Light amp Power pp 34 35 Gordeon Martin E John R Redmon Electric Cooperatives and Distribution Automation A Survey 1991 IEEE Rural Electric Power Conference pp Al 1 A1 6 Landes Toby Load Management Using Pole Mounted RTU s 1996 IEEE Rural Electric Power Conference pp A3 1 A3 4 Rhyne V T Field Demonstrations of Communication Systems for Distribution Autom
6. f human intervention required 6 By enabling a single computer to automatically initiate long complicated sequences of actions upon a certain occurrence they reduce the time needed for a human to notice and respond to the occurrence and the possibility of error 4 Unfortunately these automation systems are usually only used by very large utilities because of the cost required to purchase install and maintain them 1 For example Harris and GE s SCADA requires nearly 75 000 in basic equipment to wire up a single substation This doesn t include costs in wiring installation time and software configuration which must be purchased separately for another hefty sum 5 Most systems also have such exotic requirements as fiber optic lines running to all devices and dedicated landlines to each device 3 While this is fine for large utilities and dense areas this is cost prohibitive for monitoring only a single device Large systems also are frequently extremely complicated They require specially trained personnel to control the devices While trained personnel is probably a good idea in most cases smaller utilities do not have the necessary funds to hire these rare highly trained professionals An inexpensive system is needed to accommodate the needs of smaller utilities and the needs of companies with more remote locations 5 By using new innovations in communications all of the dedicated phone line and fiber optic cables should be rep
7. hstanding normal weather temperatures and be capable of handling rain snow and heavy winds User Configurable All hardware should be easily user configurable with no special tools other than the hardware itself and the designed software All software should be easily understood by anyone familiar with electric utility operation and minimal training 8 Modularity The system should be easily to install and upgrade All hardware should be replaceable with little or no configuration 8 Safety The device will conform to all known FCC regulations regarding radio transmissions and all NEC regulations regarding power equipment Also the hardware should have safety parameters to protect servicemen working on remotely controlled equipment 2 1 Improved Performance through Wireless Using wireless communications should allow the following 7 1 Easier installation 2 Easier maintenance 3 Greater reliability 4 Lower Cost Easier installation and maintenance should come from removing the dependencies on cables Wired systems take much longer hence much more money to install and maintain because cables must be run from the control house to every device the user wishes to monitor or control and frequently these cables are run underground to reduce breakage 3 These cables are also frequently expensive because of the speed and data integrity requirements A wireless system will be much easier and faster to install and maintain without
8. laceable with newer and cheaper wireless alternatives A less complicated system is also needed 5 By creating a system that is easily expandable while maintaining some of the most frequently used features of the existing systems smaller utilities would be free to use them with almost no training Basic computer knowledge and minimal training would be the only requirements to operate the system If such an implementation could be found then almost all of the US s electric grid and possibly the world could be automatically controlled via computer Utilities would save money by reducing the costs of maintenance crews It would also make deregulation of electric utilities a much easier thing to implement 6 Automating back feeding and switching procedures would significantly reduce downtime which is becoming an increasingly significant problem in today s wired world 5 2 Objectives 1 Speed Our system will send commands and receive results from the targeted devices within 11 minutes Range The range of the new system will allow a single transponder to monitor all devices located within the substation up to 400 feet Data integrity All devices will retain data during any and all power outages Cost The entire system must have an all inclusive installed cost below 35 000 per substation 9 Accuracy Our system should be able to receive at least 95 of all commands Weatherproof All hardware must be capable of wit
9. perating status The entire system should be able to retrieve monitored information within 5 minutes and able to transmit control sequences within 10 minutes These times however will have to be an average time There will be instances where it could take much longer to retrieve or transmit data due to several factors beyond our control such as satellite availability network control center loads and message length 2 3 Devices Being Monitored by the System Cooper 4C Reclosure Open close if can t stay close after three tries it will have to be manually closed Current Voltage Phases Cooper Voltage Regulator Read tap position Set tap position Current voltage Max min voltage Current through device Fuse Good Bad 2 4 Design of Software The PC software should be both easy to configure and easy to use It should provide monitoring and logging of data along with basic control features Graphics should be descriptive of devices and conditions and should require minimal knowledge of computers for use 8 The transponder software should also be easy to configure It will have to be bug free to maintain reliability and also obey the limitations of the transponder It must be able to detect a communications error and correct or report it depending on the severity When power is restored after an outage it must be able to quickly restart the program with no loss of data and return to an operating state 5 8 3 Acknowl
10. y as the existing systems Our design will add newly desired features such as web interface and a centralized server based SQL database system These features will create a product that works more efficiently with existing software as well as removes platform dependencies We will use Scientific Atlanta s LLEOS Little Low Earth Orbit Satellite Transponder to communicate between the host and the site via satellite A wireless communication system will be bought to allow communication between the transponder and the individual devices to control and or monitor The implementation of this now affordable technology will significantly reduce cost 9 We are going to build an I O board that will monitor and report the status of any device that supports analog and discrete data points The I O board will also be able to control discrete outputs Software will be written to allow for a simple interface to control and monitor the devices Software will be written to run on the transponder to interpret data received from the I O board This design will allow for an inexpensive alternative to existing systems while allowing most currently available features 1 This design should also allow for easier system maintenance and upgrades which are the biggest problems facing some of the larger systems 5 This system should be simple enough that anyone familiar with electric utility operations should be able to operate it unlike current systems that need dedicat
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