Along with the science and technology development, in the realization the low pressure distribution network automation has become the electrical power system development the tendency. Center the low pressure distribution network achievement loses the electrical power distribution system last the link, its realization automation degree with for the quality and the reliable close correlation which uses electricity. Therefore, this 文特 makes the simple discussion to the center low pressure distribution network automation necessity and its the realization plan.
The distribution transformer is the electrical energy direct apportionment for the low pressure user's power equipment, its performance data is the entire distribution network foundation data important constituent. Therefore, carries on the monitor to its movement parameter and the condition is necessary. This article discusses using GRPS took the means of communication, establish the distribution transformer monitor system.
In in the distribution transformer supervisory system correspondence, may use the number to pass on the broadcasting station, the GSM short news, the optical fiber turns on and so on the way. The number passes on the broadcasting station the superiority is besides an every year frequency expense, usually moves does not need the extra cost; The shortcoming is the terrain, the climate influence bigger, creates the system the reliability, timeliness is worse, is unable to report on own initiative. The GSM short news way may realize reports on own initiative; The shortcoming is according to the strip charge, the operating cost high, moreover is quite long in the holiday short message center mc server busy time time delay. Optical fiber communications ofc stable reliable, but the construction cost invests, the extension in a big way is bad, the maintenance of equipment aspect is not convenient. But the GPRS correspondence has avoided above the question.
General grouping wireless service GPRS is one kind of recent wireless data which develops on the existing GSM system passes on the number service, the goal is provides high speed wireless IP or the X.25 service to the mobile subscriber. The GPRS theory band width may reach 171.2Kbit/s, the practical application band width approximately in 40 ~ 100Kbit/s, provides the TCP/IP connection on this channel, may use in application and so on INTERNET connection, data transmission. GPRS uses the grouping exchange technology, each user may simultaneously take many wireless channels, the identical wireless channel may share by many users, resources by effective use. GPRS permission user under end-to-end grouping shift pattern transmission and receive data, but does not need to use the electric circuit exchange pattern the network resources. GPRS forever on-line, costs according to the current capacity, thus has highly effective provided one kind highly effective, the low cost wireless integrated data service. Specially is suitable for interrupted, burst characteristics and is frequent, disperser, center the small current capacity data transmission, also is suitable for the occasionally great data quantity transmission.
Second, system structure

The distribution transformer synthesis management system management system development goal is establishes a security to be reliable, can provide each kind of high-level service, and the promising application procedure execution and the implementation provides a stronger function the open style platform and the movement the system which composes in this platform many relatively independent applications subsystem, becomes to conform to the electrical power distribution system modern management requirement, distributional, open style, the modulation, may expand distribution transformer synthesis management system management system. The foundation platform besides provides the basic hardware technology and the operating system essence, but also provides such as foundation service and so on database system, information transmission, man-machine contact surface, real-time environment application procedure. Respectively includes based on the foundation platform above using the subsystem: The distribution transformer management, the line damages the management, automatically copies the table, the VQC function, the overtone data, buys the electric quantity management, the data inquiry, automatic report form, graph and with other systems connections and so on. Between these subsystems (OSA) in the foundation realizes organic crosswise and the longitudinal integration in the opening system structure, forms a complete distribution transformer synthesis management information system.
The GPRS distribution transformer supervisory system network overhead construction following chart shows, the system divides into four parts, respectively is monitors the central master station, the network proxy server, the GPRS data transmission terminal, monitors the terminal device. The master station mainly completes the man-machine alternately to work; Network proxy server primary cognizance network data link establishment and data receiving and dispatching transparent relay; The GPRS data transmission terminal completes the information on to deliver with under sends; Monitors the terminal device mainly to complete the digital quantity and simulation quantity gathering.

In this system the network proxy server may use INTELNET male net connection and so on the ADSL, LAN, uses male net fixed IP or the male net dynamic IP+DNS analysis service, considered stemming from the security, the monitoring center master station in the local area network, not straight is one after another on-line in INTERNET, is responsible for the network data link establishment and the data receiving and dispatching transparent relay through the network proxy server.
In after the GPRS data transmission terminal the electricity, it can act according to establishes or is in advance the domain name comes the initiative visit network proxy server in its internal IP address, establishes the TCP/IP link through the proxy server and the monitoring center. Monitoring center master station itself maintains each terminal IP address and the ID number which turns on, when the master station must to some monitoring terminal propose when data request, it can found corresponding according to the IP address and the ID number the terminal, under the order will send to this terminal, after the terminal response sends through the GRPS data transmission terminal the data the network proxy server port, through the port insinuated will retransmit to the monitoring center master station, namely has completed a reply -like communication flow.
Above the way is (CMNET) realizes through Internet, such user's realization cost comparison is low. If needs the redundant reliable data transmission. China moved for this kind of application provides has directly turned on the GPRS network the way. The monitoring center master station directly turns on the GPRS migration through the special line way 基站, and obtains a fixed IP address. The test point data does not need the route to the Internet network, test point DTU also uses fixed IP the address the SIM card. Uses this way composition to have timeliness well to the multi- spots network, the secure high characteristic, but relatively turns on the expense to be higher.

Third, monitors the terminal
This monitor system uses the power distribution synthesis monitor meter is and matches according to the electric power demand side management specification changes the load monitor correlation standard design, the manufacture one kind of high tech product. It uses the high accuracy numeral sampling processing technology multi-purpose, the collection data acquisition, the demonstration, the memory, the communication and so on to a body, and passable backstage software has stored up the record the data by the graph or the report form form demonstration, the printing and the analysis. Its science and technology is in the lead, the function formidable, the reliability is high, but widely applies to the power distribution automated system monitor. Its main function includes:
Preliminary survey parameter:
Three phase voltage, electric current, frequency, active power, reactive power, power factor, four quadrants electrical energies, ambient temperature and so on nine kinds, more than 30 parameters.
Technical parameter
Fixed technical parameter
Rated voltage Un: 100V
Nominal current In: 5A
Nominal frequency Fn: 50Hz
Survey accuracy
Voltage/electric current/frequency: 0.2 level
Power factor/active power/reactive power: 0.5 level
Has the merit electric quantity/idle work electric quantity: 1.0 levels
In sets dodges saves the capacity
Storage capacity: The 1024k byte, may realize continuously on 84th to use electricity the data record (every 15 minutes records)
Precision
Voltage/electric current/frequency: 0.2 level
Power factor/active power/reactive power: 0.5 level
Has the merit electric quantity/idle work electric quantity: 1.0 levels
System parameter hypothesis
Installment CT, PT change the ratio
Data storage gap
System clock
LCD contrast gradient
Has pressed the parameter
Owes presses the parameter
Has flowed the parameter

Fourth, GPRS data transmission terminal
The GPRS data transmission terminal realization monitoring center master station with monitors the terminal the communication. In this system uses ETPRO211Ai. Function and characteristic as follows:
A, function:
1. standards AT order contact surfaces, convenient programming;
In 2. TCP/IP Internet inlays the agreement stack, with ease interlocks;
3. RS232 connection way, simpler communication way;
4. passable strings mouths promotion procedure.
B, performance:
1. uses the low power loss high performance CPU to make the processor, 16 interior data bus, 128KBSRAM, 512KBFLASH, but high speed processes the agreement and the mass datas;
2. supports entire is transparent and the frame form data transmission;
3. supports TCP, IP, PPP, ICMP, UDP, TELNET, the HTTP agreement stack;
4.1 conform to ISO7816-3IC card standard SIM 卡座, supports conforms to GSM11.11 and GSM11.10, the standard SIM card;
5. simplifications connection designs, use the general 232 connections and simple AT order the interactive contact surface;
6. has supplied the more convenient power source connection outside, then uses hangs the power source. Also may from string together the mouth straight to receive the electricity;
7. entire machine power losses are smaller than 3W;
8. has consummated the false digit dialing which in the GPRS network appears, automatically falls the line to open again, long-distance awakens and so on the function;
9. supports long-distance controls and dynamic domain name analysis;
At the same time 10. has inserts the type system request in, may provide sets at the type module (not to bring outer covering, passable has inserted needle with to insert type direct system to be connected).
11th, at the same time also has the software and hardware dually 看门�? when DTU cannot the normal work, can the automatic power failure replacement.

Fifth, monitoring center master station
Master station system most in surface layer for operating system and system software. Second for system support software level, including database system, electrical power system model, data acquisition and transmission. The electrical power system model mainly refers to the electrical power system equipment object and the network analysis situs; The database system divides the movement storehouse, the foundation storehouse, the standard storehouse and the historical storehouse four parts; The data acquisition and the transmission is acts according to each kind of data from the different terminal each kind of communication agreement to gather, but certainly does not carry on processing, again for needs these data through the network distribution the system. Third for the foundation application level, the data which gathers passes through each kind of processing, through the GUI contact surface demonstrated gives the user. Fourth for the high-level application level, the data which it produces mainly is supplies power the strength system further to manage and the decision-making uses.

Below on position software mainly completes the function:
(1) the distribution transformer SCADA system transformer movement monitoring, the transformer unusual situation monitoring, the data analysis, processing and save the plate, the RTU parameter establishment and the condition demonstration. Both can obtain the distribution network movement the basic information, and provides the very good foundation for the function expansion.
(2) automatically copies the time which the table system basis establishes automatically to transcribe the distribution transformer and user's electricity number of degree. And has the electric instrument exceptionally to report an emergency, the track copies the table record and the operating record and so on the auxiliary function.
(3) the user buys the electric quantity management regarding the prestige quite bad user, carries on through the system after it first buys the electricity to supply power, and in the use electric quantity achieved when certain proportions carries on the warning.
(4) the line damages the management mainly is the area line damages the management and the line line damages the management.
(5) the switching equipment management mainly is equipment the and so on distribution line and distribution transformer management.
(6) the terminal wrong intelligence distinguishes the terminal wrongly to divide into the communication to restore, the communication severance (some terminal continuously three time summons not to measure), the terminal wireless is wrong (one day continuously ten time to summon not to measure), the wireless severance (continuously has 30 terminals to summon not to measure).
(7) shoulders the forecast through to calculate the master station and the substation all areas total active power always adds the value to come the preliminary forecast next stage the load situation.
(8) the capacitor throws cuts carries on the adjustment according to the voltage and the power factor, when the adjustment the consideration time factor and throws cuts the number of times. In adjusts in the situation which malfunctions to be able the distant place surveillance and the distant place control. If the terminal throws without the adjustment cuts the function, after the system can the distant place computation control the capacitor to throw cuts.
(9) the terminal operation may the distant place read takes or establishes the terminal the parameter, like transformer 整定 parameter and so on. May establish the switch 合闸, switch minute floodgate. May read takes or establishes the VQC parameter.
(10) meets the gift of gab with the marketing system database conveniently to provide the data pool for the marketing system.
(11) gathers the overtone data to be able to gather the user through the system each 次谐�?content.
(12) the user steals the electricity management increase user electric quantity and the power conversion for the electric quantity comparison, through the establishment scale-up factor, carries on the warning, for instance when the active power produces when the electric quantity is motionless, then has the warning.

Sixth, conclusion
Realizes in our country the low pressure distribution network automation, is improves the power supply quality, uses electricity the reliability and raises the electric power enterprise own level the need, GPRS took one recent communication method, applies in the power distribution automation has very many merits, is a comparison has the application prospect based on the GPRS correspondence distribution transformer synthesis management system management system the realization plan.