一种基于ARM的无线自动抄表与控制系统设计.docx

1、一种基于ARM的无线自动抄表与控制系统设计Design of a Wireless ARM-Based AutomaticMeter Reading and Control SystemChih-Hung Wu, Shun-Chien Chang and Yu-Wei Huangpower parameters and control signal to reach the goal of loadAbstract- This paper implements a wireless ARM-based management and power demand control. Using aut

2、omatic automatic meter reading and control system (WAMRCS) for distribution automation. The WAMRCS is designed based on a 32-bit ARM microprocessor to deal with power data processingand relay control. In order to provide a cost-effective, wireless,always-connected, two-way data link between utility

3、company and WAMRCS, the WAMRCS sends information of utility usage, power quality and outage alarm to utility company via GPRS network. Compared with analog utility meter reading by manpower, WAMRCS is more accurate, reliable, cost-effective, quick and free from man-made errors. It can provide extrac

4、apabilities such as distribution automation, load managementand time-of-use rate.Index TermsARM-Based System, Automatic Meter Reading, GPRS, Relay Control. I. INTRODUCTION With the rapid growth of population and technology, the electric power consumption and number of utility-consumers had increased

5、 quickly. In order to serve largerutility-consumers, utility company needs to employee more reading-meter workers. During the process of reading meter and writing down utility usage on record table by workers, man-made errors often happened. Therefore utility company spent cost and manpower to corre

6、ct these errors for utility-consumers. Otherwise it is uneconomical for utility company to dispatch workers to record utility usage on utility-consumers-scattered wide area.Some utility-consumers as technology factories care about quality of power supply, but analog power meter cant give enough info

7、rmation about power quality. When the power supply is unstable or outage occurs to utility-consumers, howthe utility company knows the above status and then clears power faults quickly to decrease the utility-consumers loss. Its an important point to research.At present there are more and more studi

8、es applying two-way communication technologies on distributionautomation1-4. Theses technologies can send a lot of Chih-Hung Wu is Lecture of Department of Electrical Engineering, ChienKuo Institute of Technology, R.O.C. (e-mail: zhwucc.ckit.edu.tw).Shun-Chien Chang is with Department of Electrical

9、Engineering, National Chang-Hua University of Education, R.O.C. (e-mail: boboffice.tw).Yu-Wei Huang is Professor of Department of Electrical Engineering, National Chang-Hua University of Education, R.O.C. (e-mail: huangywcc.ncue.edu.tw).system of reading meter on distribution automation can supply m

10、any capabilities such as efficient meter-reading, distribution, power monitoring and control, load managementand time-of-use rate. Supplying above capabilities is a development tendency to promote service quality for utility-consumers and improve the management efficiency for utilitycompany in the f

11、uture.IIn the past, most automated meter reading (AMR) were generally based on such media as power line carriercommunication (PLC), radio frequency (RF), telephone line and network to send data 5-7. The above communication media fact some problems such as transmission distance, transmission cost, ma

12、intenance and security of datatransmission. n order to solve these problems, we canconsider applying mobile communication system GPRS(General Packet Radio Service), which is popularly used in the world, to send power data.With rapid growth of internet and mobile communication network, future applica

13、tion service will gradually concentrate on data transmission service. GPRS has been developed maturely and has many practical applications at present 8-12. It has many advantages such as always on-line, high-speed transmission and charged fee according to the amount of transmitted data. It can satis

14、fy the need of sending power parameters on automatic system of reading digital meter.Therefore, GPRS system can build outdoor, mobile, wide-range and Multipoint-to-Multipoint data transmission channel and satisfy the need of data transmission speed for automatic system of reading digital meter.Under

15、 considerations to regional surroundings, laws and regulations, communication efficiency, interference and transmission cost, this study proposes a wireless ARM-basedautomatic meter reading and control system (WAMRCS). The WAMRCS uses sampling circuit and A/D converter totransfer analog signal of vo

16、ltage and current into digital data. The digital data then is send to embedded system to computepower parameters. This embedded system will send powerparameters to regional monitoring and control center of utility company via GPRS module connected with it. This WAMRCS applied on distribution automat

17、ion can save personnel expense of hiring reading-meter workers and can be free from human involvement; moreover, it can save large manpower from keying utility usage into database.and then converted into an equivalent digital signal by theThe hardware architecture and appearance of system are A/D co

18、nverter. shown as Fig. 1 and Fig. 2. We use PT and CT to measure the B. RCU analog signal of voltage and current. The analog signal is The RCU is an interrupting device designed for fault sampled by sample-and-hold circuit and transferred into interruption and load switching. In order to protect the

19、 D/A digital data by A/D converter. The digital data then is sent to converter from exceeding current, the D/A converter is ARM-based embedded system to compute power parameters. connected with protective relay wired in series with the This embedded system communicates with regional center of breake

20、r control circuit, so the breaker could be controlled. utility company for reporting power parameters and statusperiodically via GPRS module connected with it. The UPS is C. AES used to provide stable power supply for the embedded system Traditional power measure instruments, like watt hour and back

21、up power to prevent from short-term outage. meter and reactive power meter, cannot supply enough The WAMRCS can be divided into five parts, these five information about power quality. In order to acquire RMS parts separately are signal sampling unit(SSU), relay control value of voltage and current,

22、power factor, real power, unit(RCU), ARM-based embedded system(AES), wireless reactive power and apparent power, more and more designers communication module(WCM) and utility control center use microprocessor to design digital reading meters. The (UCC). The hardware description of five parts is intr

23、oduced microprocessor-based digital power meters have been as follows. available in the laboratory and on the market in the recentyears5-7,13,14. The ARM-based system occupies A. SSUsmall space. It support most popular communication protocolsThe analog signal scale of voltage and current on the and

24、its capabilities are more powerful than 8051 chip. The primary is proportionally transformed on the secondary via ARM-based system has been widely used in a variety of PT and CT transformers. The SSU uses sample-and-hold network equipments, such as mobile phone and PDA, and circuit to quickly store

25、the instantaneous amplitude of a become popular and cheaper at present. The ARM-based sampled input signal, and then to hold that amplitude until the embedded system has a simple operation system, so next sampling pulse. During the hold time, the sampled programmer can use popular c language to desi

26、gn program. voltage or current would be chosen alternately by multiplexerII. WAMRCS SYSTEM ARCHITECTUREUtility Control Center(UCC)Fig. 1. System Hardware ArchitectureD. WCMThe WAMRCS adopts MC35 Terminal GPRS moduleproduced by Siemens Corporation as wireless communicationmodule. This universally usa

27、ble GPRS module supports boththe GSM 900 and the GSM 1800 networks. It has high speedof wireless voice and data transmission. The MC35 TerminalGPRS module offers class 8 GPRS data communication inaddition to classic GSM services and mobile internet accessachieves a performance level previously only

28、available infixed networks. It can be integrated simply via standard RS-232 interfaces16.E. UCCFig. 2. Appearance of WAMRCS The UCC resides in the utility company and has a PC as control server with needed programs and storage to read and This study adopts NET-Start embedded system produced collect

29、power parameters from AES via communication by WSCORE Corporation to design WAMRCS. The network. The specifications of server are as follows: specifications and capabilities of NET-Start embedded system 󰀀 2.4 GHz Intel Pentium III processor are described as follows 15: 󰀀 512 Megabyte

30、s RAM (1) t is designed based on a low power 32-bit 󰀀 80 Gigabyte Hard Disk ITM network processor called ARM7TDM󰀀 15 LCD Monitor IS3C4510TM. S3C4510TM is a high performance and 󰀀 DVD-Rom Drive low cost solution for network applications. 󰀀 Floppy Disk Drive I(2) S3C451

31、0TM includes 8-kbyte cache/SRAM, and RS-232 󰀀 100 Mbps. Network Connection serial interface, two UARTs, two timers, 18 󰀀 Dot-matrix printer programmable I/O ports, and a 10/100 BaseT Ethernetcontroller. The on chip features can significantly reduce III. AES SOFTWARE ARCHITECTURE the

32、total system cost to design network devices. The function blocks diagram of AES software is shown as (3) The NET-Start embedded system has 2 MB flash ROMand 16 MB SDRAM on board, so it can execute longer Fig. 3. The functions of AES software are measurements programming code and has larger RAM to store more acquisition, relay control, tamper detection, AES setup, powerparameters computation and database management. The AES data.software runs under the Clinux operation system.Fig. 3. Function Blocks Diagram of AES SoftwareA. Clinux operation system Apparent power: VA=rms