Счетчики удаленного доступа
Дмитриенко Н. А., Добрянский М. В. Счетчики удаленного доступа // Молодой ученый. 2015. №12. С. 172-174.
Automation of the accounting of the electric power is an indispensable condition of efficiency of functioning of power supply systems in modern market conditions. Modern technologies and conditions don't allow «to stand still» long and therefore to replace the electric counters which rushed into our life counters with remote access came.
As today in the field of the accounting of the electric power there is a technical revolution. Counters from the isolated local metering device of energy become a detail of the big intelligent mechanism.
There is a need for bilateral information transfer: from system of the account to the counter and vice versa. For this purpose created counters with remote access. By means of these technologies the company delivering the electric power has opportunity at distance to receive information from the counter:
- In what quantity the electricity is consumed;
- Table of consumption of electricity;
- About illegal actions (attempt of theft of the electric power).
In turn the reader can send to the counter certain data:
- About settings of the counter;
- About change of tariffs.
In addition the system sends teams on inclusion and shutdown of loading. In order that it became possible use the built-in modem or auxiliary communication channels.
Various options with different data links are possible: PLC and radio of 2,4 GHz.
PLC communication (on a low-voltage power network) is transferred directly on network wires of 0,4 kV. The system of information transfer on PLC communication allows to read out meter readings both with private, and from the apartment houses included in the automated monitoring system and the accounting of energy resources.
Radio of 2,4 GHz — the wireless network allowing to unite to 65 000 devices. Creation of the automated monitoring system and the accounting of energy resources on the basis of a network of 2,4 GHz doesn't demand licensing of frequency and additional expenses. Today this range of radio frequencies is the most popular and perspective for use in systems to the automated information and measuring system of the commercial accounting of the electric power.
Thanks to these data links the controler doesn't need access to the room — necessary information automatically or on demand is transferred to the necessary level to the automated monitoring system and the accounting of energy resources placed in the company delivering the electric power. Besides, use of remote access gives the chance to elicit the facts of plunders of the electric power, to report about them and remotely (by means of the built-in power relay) to disconnect defaulters. And shutdown happens not only at the command of the supplier of energy, but also at excess of the set power limit.
Fig. 1. Counter of remote access
Advantages of counters with function of remote access are obvious:
- economy of means on installation and commissioning (thanks to that system wireless);
- reduction in cost of operation of the counter due to reduction shta-that controlers;
- providing Comte a beater I and data of balance on object at distance.
The counter is equipped with interfaces one of which — optical port before — the second is appointed for local data exchange, — the RS 485 interface, predna-значен for remote data exchange. Data exchange speed through optical port — 9600 bps. Initial speed of an exchange — 300 bps.
Data exchange speed through EIA 485, including initial, 9600 bps. Counter load of the interface line ¼ of standard loading for the RS485 interface. Maximum number of counters on the line 127. 1.5.24 Counters have executions the equipped miniNIC the modem with radiocha-a stately (RF) data link and a data link on a power network (PLC). Parameters of signals at data transmission on a power network correspond trebo-to vaniye of GOST P 51317.3.8–99. When signaling modulation of DCSK is used.
Working frequency of the RF transmitter is 433,9 MHz. Way of modulation of GFSK. RF transmitter signal power no more than 10 dBm. Sensitivity of the RF receiver minus 118 dBm. 1.5.25 Counters have executions the equipped ZigBee the modem (RF2) which is carrying out data transmission in the allowed range of the frequencies of 2,405–2,485 GHz. Number of the adjusted network — 29AC, the channel — B. Modems conform to the IEEE 802.15.4–2006 standard. 1.5.26 Counters NEVA A and NEVA MT 3XX HHSR, NEVA MT 32X HHSC 5(80) MT 32X HHS 5(100)A have illumination of ZhKI. 1.5.27 Information storage time in memory of the counter at absence napryazhe-a food niya not less than 30 years. 1.5.28 Intertesting interval of the counter 12