三相电度表中英文对照外文翻译文献精

1、中英文对照外文翻译（文档含英文原文和中文翻译）always adopts mecha ni cal tin plate to measure. There are some shortco mings that the measurement precision falls with machine abrasion, single time period setting and strong man power 2. I n this paper, we propose a no vel multi-rate three-phase watt-hour meter based on AT89

2、LV52. This multi-rate three-phase watt-hour meter adopts AD7752 for measureme nt. It has the characteristics which are time-shari ng measureme nt, accurate measureme nt, LCD display, automatic meter read ing, flexible time period setting, timely emendation, low cost and novel design. II. STRUCTURE A

3、ND WORKING PRINCIPLEThe no vel multi-rate three-phase watt-hour meter proposed in this paper is based upon AT89LV52 si nglechip 3. AT89LV52 has the flash memorizer with 8k bytes, cryptographical program memorizer with third class, RAM with 256 bytes, 32 programmable I/O lines, three time/ counter wi

4、th 16 bits and a two class halt with six vectors. The in terface circuit adopts I2C bus unit which is a 8 bits si nglechipwith good performa nee and suitable price. The system structure diagram is show n in figure 1.Figure 1. System structure diagramThe principle of this multi-rate watt-hour meter i

5、s reading in the multi-rate time segments using RS485 bus and noting in X25045 then take over correctional clock with RS485 bus and write in clock CMOS chip S3530A. The three-phase AC voltage and electric curre nt pass through pote ntiometer and mutual in ducta nee in strume nt respectively so as to

6、 produce small sig nal which is sent to AD7752 to complete measureme nt. The clock CMOS chip S3530A gives clock in formatio n per sec ond in the course of automatic move and an alyze this clock bel ongs to which period of time according to advance periods of time set in X25045 then save the electric

7、al en ergy in RAM memorizer accord ing to corresp onding period of time. We write it to corresp onding address of X25045 whe n the electrical en ergy achieves one degree in order to make the multi-rate measureme nt come true. This watt-hour meter hasf un cti ons of clear LCD display, missing phase d

8、etection, burthen control, halt electricity check and storage, automatic meter readi ng and so on.III. THE DESIGH OF HARDWARE CIRCUITA. Electrical en ergy measureme ntThe three-phase electrical en ergy measureme nt is realized by the low con sume CMOS chip AD7752 of ADI compa ny. The in side of AD77

9、52 adopts digital circuit besides ADC, filter and multiplication circuit which can eliminate noises effectively. The sampli ng course of voltage and electric curre nt in three-phase AC power supply loop is shown in figure 2 in which IA stands for voltage sampling of A phase. The sampling circuits of

10、 B phase and C phase are similar to A phase. The power after in tegral is transformed to electrical pulse for output. The pulse of fan-out CF enters into in terreg num INT0 of AT89LV52 through photoelectricity in sulation 4N25. CPU measures the electrical en ergy 4. We adjust the pulse nu mber of CF

11、 by comb ining the state of S1 and S2. The conn ecti on of electrical en ergy and pulse is W = M C .In which, W is the electrical energy with the unit of kilowatt-hour, M is the total pulse number,C is the pulse nu mber of ammeter. We choose C equals to 3000 that is to say every kilowatt-hour is 300

12、0 pulses.Figure 2. Circuit schematic diagramof watt-hour meterB. LCD displayThe LCD display 6 adopts HT1621 CMOS chip of HOLTEK Company to achieve twelve bits digital display. HT1621 is the LCD drivers with 128 segments (32 4) inner memorizer. The interior of HT1621 consists ofcontrol and time circu

13、its, RAM, LCD drive and watch timer. It has the merits of small volume and low cost so that it is suit to watt-hour meter. We use serial in terface which only has four lines between HT1621 and AT89LV52. The detailed conn ection is show n in figure 3. P20, P21, P22 and P23 of AT89LV52 conn ect to CS,

14、 RD, WR and DATA respectively with the use to refurbish the display of RAM. HT1621 drive CMOS chip has 48 nodes in which COM0, COM1, COM2, COM3 connect to the communal end and drive output of LCD and SG0, SG1, SG2, SG3 connect to drive output of every segme nt respectively .In additi on, an adjustab

15、le resista nee of 20k Q is put betwee n VDD and VLCD to adjust the display con trast of LCD. Experime nt shows that the con trast is better with VDD=5V and VLCD=4V.C. Serial memorizerSerial memorizer adopts low power con sumptio n chip X25045 of XICOR compa ny .It has three fun cti ons which are wat

16、chdog timer WTD, voltage supervisi on and serial memorizer E2PROM with 512 bytes. WTD can be set 200ms, 600ms and 1400ms time in tervals. The software program is read into X25045. During the no rmal running of program, WTD receives the trigger sig nal in time in tervals in order to en sure the no rm

17、al running of program. X25045 will output a high pote ntial through RESET line if WTD does not receive trigger signal in time intervals. The trigger watt-hour meter reset in order to prevent program flying away. As the serial memorizer chip, 512 bytes of X25045 are used to storage the watt-hour mete

18、r code, multi-rate periods of time, the apex electricity, smooth electricity, vale electricity and total electricity of last month and this month. Storage can be divided in to two same areas. One is used as data storage. The other is used for backup. The nu mber of storagecan be revised 100,000 time

19、s. Data can be stored for 100 years. It is connected with AT89LV52 by SPI agreeme nt bus. The conn ecti on is show n in figure 3.D. Clock circuitThe clock circuit is completed by S3530A chip. It is a low powerconsumption clock chip that supports I2C Bus. It sets the clock and calendar to the data re

20、ceived by CUP com muni cat ing with RS485. At the same time, i to walk time by its own oscillation. The crystaloscillator of 32.768 kHz is put between Xin and Xout of S3530A which is connected with CPU through latching. SDA foot and SCL foot connect to P1.6 and P1.7 of AT89LV52 respectively. There a

21、re two in terrupt alarmi ng foots can be set as sec ondinoutput or minute output synchronizing pulse which supply in terrupt sig nal to AT89LV52 with one sec ond period. Sin gle-chip system will readout the curre nt time through I2C com muni catio n in terface accord ing to this sig nal and calculat

22、e the period of time that this moment belongs to so as to realize the electrical energy measuremer different periods of time 5. This clock circuit has spare lithium battery. The powersupply VCC supply power in normal wiring and electrified for lithium battery of 3.6V. When there is power off, the sy

23、stem will automatically con vert lithium battery to clock circuit for power supply. The clock will still running accurately even the power is off.t V5S n : M.LT-Figure 3. Partial circuit figure of watt-hour meter E. RS485 Com mun icatio n8nrII：6PIO 1vexp 1PWPi2RylPIJP(-2Pld1帕P：5P(UP bPOSPIT帰RXDLXD叹I

24、XTOP2TIP22TOVT:Pi 5恵X2叩XS ,RtSi tLaiipT. viAl ?*9LV52b 6rssuSIUS JSCKzt144二 jvcc269l屮 waD41AMAX485 chip can impleme nt RS485 com muni cati on con trol of multi-rate watt-hour meter. MAX485 chip has RS485 com muni cati on protocol. It can take 128 hypogenous computers. Its transmission distance is gr

25、eater than 1km and its tran sfer rate is up to 250kb per sec ond. The watt-hour meter conn ects with the unit con troller through the RS485 bus. Each unit has a cell con troller can man age 128 rate watt-hour meter. The cell con troller conn ects to power man ageme nt computeEach watt-hour meter has

26、 one and on ly meter nu mber with eight bits of hex. The electrician should write the user s information and meter number and then import to thepower man ageme nt computer for in itial in stallati on so ad to complete the connection of user and man ageme nt computer. Man ageme nt computer sends sett

27、 ing of period of time and clock in formati on with the manner of broadcast com muni cati on without address information. PC uploads information by the way of calling address. F Lack Phase detect ion and relay con trolIt ca n achieve relay con trol 7 with P27 of AT89LV52. P27 cancon trol relays usin

28、g 4N25 photoelectricity isolator so as to complete powersupply and power con trol. Lack Phase detect ion gets the sig nal from fan-out of the relay and conn ects to 1 foot of photoelectricity isolator after pass ing a 75K resista nee, the diode half-wave rectifier and capacitive filteri ng respectiv

29、ely. We detect the 4 foot of isolator to determ ine whether there is the lack of phase. If there is lack of phase, we detect aga in after 2 sec onds overtime. We break off the power immediately if there is lack of power after the twice confirmation. In power protection circuit, it uses the INT1 inte

30、rrupt foot of AT89LV52 to detect sig nal.When there is a sudden power off, INT1 jumps into a low voltage and the INT1 in terrupt en ters to the power protectio n program relyi ng on the en ergy storage capacitor to save data. In the system, pulse output of AD7752, relay con trol port and the in puts

31、 of lack phase detecti on all use photoelectric isolator 4N25. It sends electrical sig nal by light coupli ng which can enhance the ability of an ti-jam min g. IV. THE DESIGN OF SOFTWAREA. The distribution of resourceThe software program in cludes main program, X25045 read and write program, RS485 s

32、erial com muni cati on program, in terrupt serve program, timer han dli ng program, HT1621 display con trol program, electrical en ergy measureme nt in differe nt period of time and power dow n protect ion program, and system self-check ing and an ti-i nterfere nee han dli ng program .In terrupt res

33、ource distributi on of system is: INTO in terrupt is used as AD7752 pulse measureme nt, INT1 as synchroni zati on detecting, timer TO as 100 ms timing, T1 as 1ms timing, and T2 as baud rate generator for serial com muni cati on program. RS485 asynchronous com muni cati on is set to receive in terrup

34、t and check in formati on for sending.B. Module desighThe flow chart of main program is shown in figure 4. The watt-hour meter should be able to initialize at each power up time. The initializing program in cludes sett ing work ing mode of timers, serial stomata and in terrupts for AT89LV52,writ ing

35、 control word into X25045, S3530A and HT1621. This system sets three periods of time. The sin glechip reads clock value from S3530A per sec ond the n an alyze this clock belongs to which period of time according to advance periods of time set in X25045 the n save the electrical en ergy in RAM memori

36、zer accord ing to corresp onding period of time. We write it to corresp onding address of X25045 whe n the electrical energy achieves one degree. The LCD display with 16 bits shows period of time and electrical energy information in turn. Figure 4. Flow chart of main program V.TESTING RESULTError me

37、asurement and running test have been made in Zibo Billion Electron Co., Ltd. The epige nous computer completes the setti ng of time man ageme nt. There are three-rate period of time. The first period of time is vale electricity from 00 point 00 minute to 06 point 30 minutes. The second period of tim

38、e is apex electricity from 06 point 30 minu tes to 22 point 30 mi nu tes. The third period of time is smooth electricity from 22 point 30 minutes to 24 point 00 minute. The setting of rate period of time is sent to computer man ageme nt system by electric power compa ny accord ing to n ati onal poli

39、cy and saved in X25045. The apex electricity, smooth electricity, vale electricity and total electricity per month read saved in electrical en ergy meter and sent to epige nous computer through cell con troller. The com muni cati on baud rate is 9600 bits per sec ond. The checkout platform of 0.1 gr

40、ade sta ndard electro nic power meter is used as standard meter and the multi-rate watt-hour meter is the tested meter. Billion Electr on Compa ny has carried out test ing accord ing to differe nt load running. The measured data is shown in table 1 with the burthen of 30kW.ItemNonual meteiTestedmere

41、rError (%)cleciTKiir3 00029960.13%Cslm ele-c XKit?3 WO工洱50.17%VaJ 霁3.0P02,9970,10%Torsi elctricin9.000S 988013%0(5.09 10306 09 10:300.00.000111口 E0;fll0;01O.WTj Jf 1、 RwdSJOAMrawiic c Icctncon mfi- aC LJimimiic jIlSer id chuRrfLtfbi%；!如d dfpUy *FOWH 15电处TABLE I. COMPARE OF NORMAL METER AND TESTING M

42、ETERThe testi ng result in dicates that the error of this multi-rate watt-hour meter is less than 1%, belongs to 1.0 grade. The return reading of electrical energy is precision and the emendation of time is timely and right. By testing, the method of decreas ing errors for electricity meteri ng can

43、be obta in ed. Firstly, adjust the sampli ng resista nee of AD7752 to accurate value. Secon dly, the value of this resista nee is needed less varying with temperature. Thirdly, during electricity metering progress, when mantissa portion of electricity is less than0.01, the remaining pulse should be accessed together, thus cumulative error caused by lack of 0.01degree en ergy loss could be avoided.VI. CONCLUSION AND EXPECTATIONThe multi-rate watt-hour meter achieves electrical en ergyco