【 Weak current College 】 experts discuss centralized meter reading and installation problems solution

I. preface
As China's electric power system of deepening, the rapid development of the electric power industry, electric power has entered the market as a commodity, accounting, electricity charges and the calculation of electric power accounting system of control and management need further improvement and perfection, to this end, the 1998 national General establishment of a nationwide with three to five years to achieve "a household, one table, automatic meter reading," strategic deployment.　　Our company has developed low-voltage power line automatic meter reading system and matching system, after a year of field trial run, is now completely ready for large scale production. Automatic meter reading system is modern microelectronic technology, smart devices, communications, computer technology, professional range of advanced technology integration. Through the public low-voltage power line acquisition household consumption information, centralized storage, unified management, greatly improving the property management sector and water electric government functions of management and economics. Due to industry management system as well as many other to objective conditions, which are mainly intended for residential customers and the property management Department, the next generation of products will be primarily water electric and other functional departments of government management, the realization of a truly "local network" centralized management, unified billing, consolidated revenue, so that the entire community-wide energy management automation. In the past, every building will be sent by hand, meter reading, not only copied data cumbersome, and statistics. Using an automatic meter reading system, the computer directly collecting water each household and electrical data for analysis, collation, storage, and calculate the associated costs. From social benefits, automatic meter reading system synchronization enables centralized intelligence management, reduces human factors brought about numerous changes in the tariff policy, when tabbed meters need operations personnel at the scene changes to the table, and an automatic meter reading system use Central Administration to change the software setting to achieve, an automatic meter reading system power consumption meter, it is only for 0.5W tabbed table power consumption of 20%. 98 in Guangdong Province, in the province-wide implementation of electronic energy meter, because of its small power consumption, a year in the province's electricity saving nearly 100 million Yuan. In addition, Chengdu city, "a a" project was listed as a municipal work one of the top ten good deeds. CCTV reported funding of 100 million yuan in Guangzhou City dedicated to collecting system, Xi'an evening August 11 also reported on the provincial deputies propose "a a" programme after the social repercussions, so select the power line meter reading system, to better meet user needs to achieve scientific management, the aim of increasing effectiveness of drawdown. This is generally recommended power system at home and abroad, the best reading meter management systems. Working principle
(1) be installed on the end of the gathering meter table header collection meter output of counter pulse, the acquisition process and the adoption of low-voltage power line (or line) for upload to the concentrator.
(2) installed on the distribution of the concentrator, the adoption of low-voltage power line collection the collector of meter data for electricity, and the power to effectively manage data. And on the basis of computer instructions (i.e., meter-reading software), with the public telephone network, the meter data community (concentrator) copy received the computer.
(3) is installed in outdoor distribution Cabinet of repeaters can increase the concentrator and collector of communication success rate in order to ensure correct and reliable data collection system.
(4) shall be installed in the distribution of data collection software, complete community meter copied, report generation and data exchange. III. characteristics
1. easy maintenance
Normal system operation will be maintenance-free. If you need to replace the network devices including meter, as long as the replacement computer reset after adoption of the relevant parameters instead of changing the scene other hardware and parameters, the entire operation only takes a few minutes, this MCU core, other types of automatic meter reading system is difficult, because they are network-based products. 2. the system upgrade is easy
With the development of the electricity supply industry, some operating parameters and actions need to be adjusted. This is our system without any problems, in few minutes the worst is yet to come, but for other non-network-an automatic meter reading system is impossible, they must modify hardware, remove the reload!
3. real-time acquisition
Due to our automatic meter reading system is a network-type products, and other automatic meter reading system is essentially the difference. Any member status in the system, they may send and receive data without master node management and polling, that fully reflects its real-time.
4. remote management
Due to our automatic meter reading system is a network-type products, therefore it is in addition to data acquisition, as long as the slightly increase the point function devices, you can enable automatic meter reading system with control function, the formation of a true with remote management capabilities for measuring and control system. IV. technical performance and indicators system meets People's Republic of China power industry standards.
System with 24 hour nonbreaking working system.
Due to the use of low-voltage lines as network communications channel, traffic safety and reliable, it does not require on-site wiring, all nodes as long as the nearest connected to the same line to the Internet. The communication complies with the FCC (Federal Communications Commission in the United States) and CENELEC (European electrical technology standards Committee) standard EN 50065-1, the use of frequency bands in the range of 125 ~ 140kHZ.
The system does not require a dedicated CPU and server, each node uses the independent power supply, independent work. Any node failure, withdrawal or increase the node does not affect the normal operation of the system. The system can use the remote PC or handheld meter reading machine receives the data, set or modify the network node parameters, such as a table numbers, tables, constants, table, floor and reorganization period, etc.
All nodes are made of three-phase power supply parallel work, disconnect any one phase or two-phase power supply, have no effect on the node's normal work.
Each collector node can also collect 16 block Watt-hour meter pulse data and automatic fault detection meter features once Watt-hour a load without issuing pulse count, be promptly detected and meter data transmission at the same time send failure flags.
Meter data across multiple periods, respectively, in order to supply aggregate departments use the peak and Valley, flat pricing multi-period timesharing system.
> System with a second data transfer method, that is, a remote PC through the serial port the modem (Modem) through a telephone line and field use meter reading computer joins concentrator node sends instructions and collecting data.
System without the use of number plates set the node address is hard in all nodes use the remote control to set the address number.
When table constants for 1600imp/kW. H, collector node to correctly capture 16 channel continuous 2.5HZ of pulse frequency, which allows each single phase energy meter output current reach 25A.
When a power outage or distribution transformer voltage fluctuations meter data is not lost, its reliable retention of up to 10 years.
The system allows the voltage range of 220V ± 15%.
Node using L-N differential mode means low voltage power cable channel packet transmission mode, the power line transmission rate 1200bps. Phone line and meter-reading computer data communication speed of 9600bps.
Average power input node is less than 6W.
System complies with ISO (International Standardization Organization) of the OSI (open systems interconnection) standards.
System-level anti surge voltage and over current measures to have the grid voltage change adaptability and functionality of the resist lightning.
This system has been in the EMC monitoring center through IEC1000-4-1, IEC1000-4-4 and IEC1000-4-5 electrical fast transient burst immunity and surge immunity test (E Word 029601 test reports). Electrical fast transient burst immunity level harsh classification reach Ⅳ (2000V); harsh classification surge immunity reached grade ⅲ (6000V).
The system can run continuously for more than 10 years.
Node operating temperature:-25 ° c to + 55 ° c; relative humidity: 95% (without condensation).
This system also applies to other pulse modulation of measuring table with or special equipment.
5. frequently asked questions 1, install an automatic meter reading systems need to have the kind of conditions? 1) user scene with tables should have a pulse sender functionality.
Because an automatic meter reading system for collecting data from pulse sender table, pulse sender table of quality should be reliable, the sender's pulse must be accurate.
2) requires remote meter reading management of users, should be equipped with remote meter reading channel and device to PC and concentrator establish communications connection.
Such as: PSTN (PSTN), a wired remote channel, users need to apply to the telecommunications sector. 3) for the residential property management user, PC (data management system) and concentrators can be installed in a room together, such as monitoring, can be connected directly via the RS232 interface, do not have to be equipped with remote meter reading channels and devices. If the host computer and concentrator installation distance, available through the Community internal telephone line for meter reading management. Conditions for the good of the community, through Ethernet, network meter reading management. 4) if the downlink (concentrator and terminal equipment: collector, smart table, powered down, control modules, and other distribution channels) adopt RS485 communication mode, the user must have the cable laying conditions. 5) uses the meter reading system user, you need good management system, staff have a high quality. 2, the company's acquisition of specifications and types? collector is an automatic meter reading system for terminal equipment for the collection of table data. MRU internal circuit with microprocessor, main implementation table data acquisition, data communication capabilities. Therefore, MRU is a smart device. Due to the complexity of the data collection system, are classified into various types of MRU, our collector products mainly include: by purpose: meter collector
Press the number of channels: 16 tables
Press communication: carrier type, RS485 bus type.
Press power consumption mode: low power mode and normal mode.
3, 485 and carrier what advantages and disadvantages of? RS485 bus and PLC power line carrier are wired communication mode, but there are significant differences between the two, has advantages and disadvantages, mainly reflected in the following areas: communication rate: 1)
RS485 communication rate significantly superior to the PLC. Power interruptions can affect PLC communication, so communication distances shorten, at this point you may use the relay function, PLC communication speed also decreased significantly.

Site construction: 2)
Use of the great advantages of PLC communication does not require a dedicated cable laying, does not undermine the pavement or other facilities not affect beauty.

3) maintenance:
Because there is no dedicated cable carrier easy to maintain. On the way, RS485 communication cables of short circuit, open circuit fault finding difficult, node failures may also prevent bus hanging death, and vulnerable to attacks of lightning.

Reliability: 4)
As a result of failure-prone RS485 bus cable, reliability means a PLC.

Cost: 5)
As a result of saving construction and cable costs, low cost way of PLC.

4. collector and concentrator have infrared communication way? collector and concentrators are equipped with infrared communication interface, this is a feature of our system. Via the infrared interface, you can implement a meter reading, setting up, testing, and other functions. 5, system performance? stability? characterized? 1) flexible means of communication.
Uplink interfaces including: PSTN phone line communication interface, IRDA infrared interface.
Downlink interface RS485 interface, included: PLC power line carrier communication interface.
2) reliable pulse acquisition programmes.
Collector in acquisition pulse, just a simple count, and the use of the software and hardware combination of pseudo pulse rejection measures, thereby ensuring the reliability of pulse acquisition.
3) excellent low-power performance.
Low power design collector is non-volatile memory that can be maintained when power failure10 years without losing data.
4) mixed carrier programme.
On-site communication programmes can select RS485 mode, you can also select PLC power line carrier. Allows on-site installation is flexible and convenient, users have more choices.
5) with lightning.
RS485 bus vulnerable to lightning damage, our system is equipped with a bus with the lightning arrester 3-level protection measures can be effective protection system. 6. technical advantage 1) compared with similar foreign power grid, developed countries are already very perfect running conditions, with high levels of power management, carrier transmission rate is relatively high. But because the foreign carrier technology is built on the foreign network signal noise, but our power network interference signals are very complex. And abroad have not carrier technology applied to the remote power-off, meter reading and warning prompt, therefore, the foreign carrier spread spectrum technology in use of automatic meter reading systems are not yet standards and our country.　　Our research and development of low-voltage power line carrier for automatic meter reading system is our power grid situation tailored automatic meter reading systems, automatic meter reading system compared with foreign countries, the system has the following advantages: apply to the current network management level is low, the low carrier transmission rate. With the use of carrier technology for remote power-off, meter reading and warning hints, and other functions. 2) compared with domestic like relay (relay)
PLC-based technology for automatic meter reading product will be subject to transmission limitations of the distance.
Power line carrier automatic meter reading system tables have a mutual support, the ability of each relay. Investment in the province
First of all, this system is one of the principles of design will demand greater equipment cost pressure to a minimum, the number of expensive equipment to a minimum;
Secondly, this system uses power line communications media, to do without the construction line of construction and investment, to avoid the expensive price of wireless devices. Installation is simple and convenient connection of small (and general electric meter installation method are the same) without special signal cable, do not have to set Assembly table.　　It is currently the smallest installation of products. Remote control, power
There are many domestic metering system generally only purely for meter reading functionality, but for user default tariff was no longer available. While this system on how reminders tariffs presented a set of solutions addressing has been electricity charges Department headaches. Through remote control of the modern means to achieve remote control power, transmission; PC software may issue a directive in a few seconds the distance control a block table loses power, transmission carrier. 　　Greatly reduce the meter reading staff, productivity. At present, China has the capacity to produce automatic meter reading system of enterprises about 10 families, this product range is very wide, but 80% of the manufacturers are limited due to the scale of production and technology behind the leading product quality has obvious defects or lack of stability, and performance has not been widely promoted. To sum up, it can be concluded: low-voltage power line meter system advanced technology, reliable quality, with other manufacturers of irreplaceable superiority.