一種基于ARM的無線自動(dòng)抄表與控制系統(tǒng)設(shè)計(jì).

1、Desig n of a Wireless ARM-Based AutomaticMeter Readi ng and Con trol System Chih-Hu ng Wu, Shun-Chien Cha ng and Yu-Wei Huang power parameters and con trol sig nal to reach the goal of load Abstract- This paperimpleme nts a wireless ARM-based man ageme nt and power dema nd con trol. Usi ngautomatic

2、automatic meter readi ng and control system (WAMRCS) for distributionautomatio n. The WAMRCS is desig ned based on a 32-bit ARM microprocessor to dealwith power data process ing and relay con trol. I n order to provide a cost-effective,wireless, always-c onn ected, two-way data link betwee n utility

3、 compa ny and WAMRCS,the WAMRCS sends information of utility usage, power quality and outage alarm to utilitycompa ny via GPRS n etwork. Compared with an alog utility meter read ing by man poweWAMRCS is more accurate, reliable, cost-effective, quick and free from man-made errors.It can provide extra

4、 capabilities such as distributi on automati on, I oad man ageme nt andtime-of-use rate.In dex TermsARM-Based System, Automatic Meter Readi ng, GPRS, Relay Con trol.INTRODUCTION W ith the rapid growth of populati on and tech no logy, the electric powercon sumpti on and nu mber of utility-c on sumers

5、 had in creased quickly .In order to servelarger utility-c on sumers, utility compa ny n eeds to employee more read in g-meterworkers. During the process of reading meter and writing down utility usage on record tableby workers, man-made errors ofte n happe ned. Therefore utility compa ny spe nt cos

6、t andman power to correct these errors for utility-c on sumers. Otherwise it is unecono mical forutility compa ny to dispatch workers to record utility usage on utility-c on sumers- scatteredwide area.Some utility-c on sumers as tech no logy factories care about quality of power supply,analog power

7、meter can t give enoogmanon about power quality. When the power supplyis un stable or outage occurs to utility-c on sumers, how the utility company knows theabove status and then clears power faults quickly to decrease the utility-consumersloss.Its an importanteeahbh.At prese nt there are more and m

8、ore studies appl ying two-way com muni cati on tech nologies on distributi onautomatio n 1-4. Theses tech no logies can send a lot of Chih-H ung Wu is Lecture ofDepartme nt of Electrical Engin eeri ng, Chie nKuo In stitute of Tech no logy, R.O.C. (e-mail: .tw).Shun-Chien Chang is with

9、 Department of Electrical Engineering, National Chang-Hua University of Educati on, R.O.C. (e-mail: .tw).Yu-Wei Huang is Professor of Departme nt of Electrical Engin eeri ng, Nati onal Chang-Hua University of Education, R.O.C. (e-mail: .tw).system of readi ng meter on distributi on

10、 automati on can supply many capabilities such asefficient meter-reading, distribution, power monitoring and control, load man ageme ntand time-of-use rate. Suppl ying above capabilities is a developme nt tendency to promoteservice quality for utility-c on sumers and improve the man ageme nt efficie

11、 ncy for utilitycompany in the future.Iln the past, most automated meter read ing (AMR) were gen erally based on such mediaas power line carriercom muni cati on (PLC), radio freque ncy (RF), teleph one line and n etwork to send data5-7. The above com muni cati on media fact some problems such as tra

12、n smissi on distanee, tran smissi on cost, maintenance and security of data tran smissi on. n order to solvethese problems, we can con sider appl ying mobile com muni cati on system GPRS(Gen eral Packet Radio Service), which is popularly used in the world, to send power data.With rapid growth of int

13、ernet and mobile com muni cati on n etwork, future applicatio nservice will gradually concen trate on data tran smissi on service. GPRS has bee ndeveloped maturely and has many practical applications at present 8-12. It has manyadva ntages such as always on-I ine, high-speed tran smissi on and charg

14、ed fee according to the amount of tran smitted data. It can satisfy the n eed of sending power parameterson automatic system of read ing digital meter.Therefore, GPRS system can build outdoor, mobile, wide-ra nge and Multipoi nt-to-Multipoint data transmission channel and satisfy the need of data tr

15、ansmission speed forautomatic system of readi ng digital meter.Un der con sideratio ns to regi onal surro undin gs, laws and regulati ons, com muni cati onefficie ncy, i nterfere nee and tran smissi on cost, this study proposes a wirelessARMbasedautomatic meter readi ng and control system (WAMRCS).

16、The WAMRCS uses sampli ngcircuit and A/D con verter totran sfer an alog sig nal of voltage and curre nt into digital data. The digital data the n issend to embedded system to compute power parameters. This embedded system willsend power parameters to regi onal mon itori ng and con trol cen ter of ut

17、ility compa ny viaGPRS module conn ected with it. This WAMRCS applied on distributi on automati on cansave pers onnel expe nse of hiri ng read in g-meter workers and can be free from huma ninvo Iveme nt; moreover, it can save large man power from key ing utility usage intodatabase.and the n conv ert

18、ed into an equivale nt digital sig nal by theThe hardware architecture and appeara nee of system are A/D conv erter. show n as Fig. 1and Fig. 2. We use PT and CT to measure the B. RCU an alog sig nal of voltage and current. The an alog sig nal is The RCU is an in terrupti ng device desig ned for fau

19、lt sampled bysample-and-hold circuit and transferred into interruption and load switching. In order toprotect the D/A digital data by A/D converter. The digital data then is sent to conv erter fromexceed ing curre nt, the D/A conv erter is ARM-based embedded system to computepower parameters. conn e

20、cted with protective relay wired in series with the This embeddedsystem com muni cates with regi onal cen ter of breaker con trol circuit, so the breakercould be con trolled. utility compa ny for report ing power parameters and statusperiodically via GPRS module conn ected with it. The UPS is C. AES

21、 used to providestable power supply for the embedded system Traditi onal power measure in strume nts,like watt hour and backup power to preve nt from short-term outage. meter and reactivepower meter, cannot supply eno ugh The WAMRCS can be divided into five parts, thesefive in formatio n about power

22、 quality .In order to acquire RMS parts separately are sig nalsampli ng un it(SSU), relay con trol value of voltage and curre nt, power factor, real power,un it(RCU), ARM-based embedded system(AES), wireless reactive power and appare ntpower, more and more desig ners com muni cati on module(WCM) and

23、 utility con trol center use microprocessor to desig n digital read ing meters. The (UCC). The hardwaredescriptio n of five parts is in troduced microprocessor-based digital power meters havebee n as follows. available in the laboratory and on the market in the rece ntyears5-7,13,14. The ARM-based s

24、ystem occupies A. SSU small space. It supportmost popular com muni cati on protocolsThe an alog sig nal scale of voltage and curre nt on the and its capabilities are morepowerful tha n 8051 chip. The primary is proporti on ally tran sformed on the sec on daryvia ARM-based system has bee n widely use

25、d in a variety of PT and CT tran sformers.The SSU uses sample-a nd-hold n etwork equipme nts, such as mobile phone and PDAand circuit to quickly store the instantaneous amplitude of a become popular and cheaperat prese nt. The ARM-based sampled in put sig nal, and the n to hold that amplitude un til

26、the embedded system has a simple operati on system, so n ext sampli n pulse. During thehold time, the sampled programmer can use popular c Ian guage to desig n program.voltage or curre nt would be chose n alter nately by multiplexerII. WAMRCS SYSTEM ARCHITECTUREUtility Con trol Ce nter(UCC)Fig. 1. S

27、ystem Hardware ArchitectureBISCui icrlrGGSX IGdAr*EH I卜Krrr1l*1匚陽I心制hn曲如AILSKhU-k-iFMRn4*TiHFrukIkli,d. hUbiiijiilft.Vi4toialrrJ IMRCl iD. WCMThe WAMRCS adopts MC35 Termi nal GPRS module produced by Sieme ns Corporatio n as wirelesscom muni cati on module. This uni versally usable GPRS module suppor

28、ts both the GSM 900 and theGSM 1800 networks. It has high speed of wireless voice and data tran smissi on. The MC35 Termi nalGPRS module offers class 8 GPRS data com muni cati on in additi on to classic GSM services andmobile internet access achieves a performa nee level previously only available in

29、 fixed networks. It canbe integrated simply via standard RS232 in terfaces16.E. UCCFig. 2. Appeara nee of WAMRCS The UCC resides in the utility compa ny and has a PC as con trolserver with n eeded programs and storage to read and This study adopts NET- Start embedded systemproduced collect power par

30、ameters from AES via commu nication by WSCORE Corporation to desig nWAMRCS. The network. The specificati ons of server are as follows: specificati ons and capabilities ofNET-Start embedded system 2.4 GHz In tel Pen tium III processor are described as follows 15:512 Megabytes RAM (1) t is designed ba

31、sed on a low power 32-bit 80 Gigabyte Hard Disk ITMnetwork processor called ARM7TDM 15 LCD Mon itor IS3C4510TM. S3C4510TM is a high performanee and DVD-Rom Drive low cost solution for network 即 plicatio ns.Floppy Disk Drive I(2)S3C4510TM in cludes 8-kbyte cache/SRAM, and RS-232100 Mbps. Network Conn

32、 ection serial in terface,two UARTs, two timers, 18Dot-matrix prin ter programmable I/O ports, and a 10/100BaseT Ether netcontroller. The on chip features can significantly reduce III. AES SOFTWARE ARCHITECTURE the totalsystem cost to desig n n etwork devices. The fun ctio n blocks diagram of AES so

33、ftware is show n as (3)The NET-Start embedded system has 2 MB flash ROM and 16 MB SDRAM on board, so it can executeIon ger Fig. 3. The fu nctio ns of AES software are measureme nts program ming code and has largerRAM to store more acquisiti on, relay con trol, tamper detecti on, AES setup, power par

34、ameterscomputati on and database man ageme nt. The AES data.software runs un der the Cli nu xQperati on system.Fig. 3. Fun cti on Blocks Diagram of AES SoftwareA. Clinux operation system Apparent power: VA=rms rms On the aspect ofWAMRCS software, the Net-StartWattembedded system uses 卩 Clinux as ope

35、rating system core. Power factor: cos0=VADeveloper can use c-la nguage to program software and build it as executive file on pers onalcomputer beforeha nd. This 22Reactive power:Var=- executive file will be loaded in to microprocessor of embeddedsystem through RS-232 from PC and runs un der Cli nux

36、卩C. Data fields in AES database operating system.The data fields in AES database are summarized as table 1. The characteristics ofpCli nux are in troduced as followsThese fields can be remotely modified by UCC after log in 17:(1)Clinux is a derivative of Linux 2.0 kernel in ten ded for ide ntificati

37、 on of access ing AES is confirmed.microc on trollers without Memory Man ageme nt Un its VIVAWatt(MMUs). (2) The source code is ope n and desig ned as module mode.(3) Clinux kernel is much smaller than the original Linux2.0 kern el, while retai ning the mai n adva ntages of the linux operat ing syst

38、em: stability, superior network capability, and excelle nt file system support. (4) Cli nux supports 卩 nu merous popular n etworking protocols. It is an intern et-ready OS perfect for embedded systems.In addition, when we develop a program, itnotice Shafottowing items:(1) Because the卩 Clinux doesn t

39、 support MMU function, we cannot use the capabilityof virtual memory on program desig n.(2) Whe n alarm happe ned duri ng the process of compili ng program, we must solve any errors orproblems.(3) If the program can run on PC without any error, it does ntmean that the program also can run on the emb

40、eddedsystem Net-Start properly. B. Computati on of static power parametersAfter tran sferri ng an alog measureme nts into digital measureme nts, we can use the followi ng equations to compute static power parameters.1) Root Mean Square (RMS)If N sampled data V1, V2, V3,VN during a period areacquired

41、, the RMS value of voltage V is give n byv1 刀 Nv2rms=Nk=1kwhere Vk represe nts the Kth sampli ng value of voltage.If N sampled data 11, 12, 13,IN during a period areacquired, the RMS value of curre nt I is give n byI1N2rms=NEk=1Ikwhere Ik represe nts the Kth sampli ng value of curre nt. 2) Power If

42、N samples of voltage sig nalV1, V2, V3,VN and current signal I1, I2, I3,IN during a period are acquired atthe same sampli ng in sta nts, the real power is give n by Watt=1NNEkkk=1VIThe values of reactive power, power factor and appare nt power can be give n from thefollowi ng equati ons.TABLE IAES D

43、ATABASE SUMMARY Field Numberof bytesComme nt AES ID 2 Device ID AES IP 4 AES IP address Login Login UCC IP 4 UCCIp address UCC Port 4Communi catio n port with UCCSampli ng Time 4 Voltage and Curre ntampli ng time setupReport Time 4Period of sending powerdata to UCC Relay Output Status 1 VRR VS 4 S p

44、hase voltageVT 4 T phase voltageIRR ISS ITT Real power 4Reactive power 4 Appare nt power 4Power factor 2 D. tamper detecti onIn rece nt years many utility con sumers attempt to obta inelectrical energy illegally. This incoming loss of stolen power for utility companies inchina is even more than 2416

45、 million $USD. Its necessary for utility meter to have thecapability oftamper detecti on. This study uses a method of tamper detection proposed by Misra, R.B. and Patra, S.18. The followi ng eve nts are con sidered for tamper detect ion by the method.Miss ing pote ntial eve nt Curre nt un bala nee e

46、ve nt Curre nt reversal eve nt If any above eve ntoccurs, the AES will record the meter status in database and inform UCC about tamper warning on the insta nt.IV. UCC SERVER SOFTWARE ARCHITECTURE The UCC n ot o nly reads and collects powerparameters from AES, but also gives relay-co ntrol comma nds

47、to AES via5com muni cati on n etwork. The com muni cati on media betwee n Acco unt and password en crypti onUCC and AES is two-way. The main capabilities of UCC are Lock AES and UCCP address as source and as follows. desti nati on IP addressPower data acquisiti on cen ter Tran smissi on data and con

48、 trol comma nds en crypti onRCU breaker control VI. CONCLUSIONS AND SUGGESTIONS AES setup and modificatio nComb in ati on with the utility billi ng system (1) This research uses asampling circuit to get voltage and The function blocks diagram of UCC server software is curre nt sig nalinto A/D conv e

49、rter of an embedded system. show n as Fig. 4. The fun cti ons of server software are UCCWith the con verted data, power parameters can be man ageme nt, AES relay con trol, tamper Detection calculated. The power parameters are the n sent to the man ageme nt, user acco unt man ageme nt,graph of con su

50、mer con trol cen ters of utility compa ny via the GPRS device utility usage and report print.The software of server system connected to the system. With this system, fewer people are required toprocess the data. The automation can also adopts VB as programming Ian guage and SQL server asavoid any co

51、n flicts or problems due to huma n errors. database man ager. The server system runs under win dows Furthermore, the system allows sav ing the time and the 2000 server. cost to in put thedata into databases.(2) By using an automatic meter readi ng device in electricity V. SECURITY OF WAMRCS distribu

52、tionsystems, n ot o nly does in crease it the The AES adopts TCP/IP protocol to com muni cate with efficiency of meters read ing, but also provide capabilities UCC via com muni cati on n etwork, so the transmissi on data like electricity con trol, load man ageme nt, and time-of-use betwee n AES and

53、UCC maybe in tercepted and received by rate. hackers in Intern et. Mea nwhile, the AES is a n etwork device (3)Since embedded systems and GPRS devices are see n as a n etwork point in Intern et, anyone canaccess AES expe nsive, readers for differe nt meters, like electricity, from any where. Its an

54、importantpoint to prevent the AES watanrd natural gas, can share one embedded system database from unauthorized access and modificati ons. This with GPRS built-in. If several customers live in an study takessome security strategies to protect AES database apartment building, they only need to purcha

55、se onefrom hacker invasion and transmission data from interception. system for the whole building to lower thecost. These security strategies are listed as follows.Log in ide ntificati onFig. 4. Fun cti on Blocks Diagram of UCC Server SoftwareYu-Wei Hua ng was born in the Taiwa n, R.O.C., 1959. He r

56、eceived his BSEE and MSEE degree fromNatio nal Tsing Hua Uni versity in 1981 and 1983 1 Patrick, A., Newbury, J., and Garga n, S., Two-waycom muni cati ons respectively, Ph.D. from National Cheng Kung University in 1989. Since 1996,systems in the electricity supply in dustry, IEEE Trans. Power Deliv

57、ery, he has bee n a professor at National Chan g-Hua Un iversity of Educatio n. His Vol.13, pp. 53 -58, Jan. 1998. research in terests are inmicroprocessor control and power system. 2 Miura, N., Sato, H., Narita, H., and Takaki, M., Automaticmeter-read ing system by power line carrier com muni cati

58、on s, in Proc. C 1990 IEEGeneration, Transmission and Distribution, Vol. 137 Issue: 1, pp. 25 -31.3 Donovan, D., Cellular con trol cha nnel com muni catio ns for distributi on automation applications,in Proc. 2001 EEE/PES Transmission and Distribution Conference and Exposition, Vol.2 , pp. 982 -984.

59、4 An ders on, H.R., Measured data tran smissi on performa nce for AM broadcast-VHF radiodistributio n automati on com muni cati on system, IIEEE Trans. Power Delivery, Vol. 4 Issue: 1, pp. 82-89, Jan. 1989.5 Shwehdi, M.H. and Jacobsen, C., A Microprocessor-Based Digital IIWattmeter System Desig n, i

60、nProc. 1996 IECEC En ergy Con versionEngineering Conference, Vol. 3, pp. 1840 -1845.S.W. Lee, C.S. Wu, M.S. Chiou, and K.T. Wu,“Desig n of an automaticmeter reading system,”in Proc. 1996 IEEE IECON 22nd International Conference on the In dustrialElectr oni cs, Con trol, and In strume ntati on, Vol.1