Single phase 2/3 wire Electronic kWh meter (ANSI C12.1)
DDSIF511/512 meter is a single phase 2/3-wire electronic KWH meter with the functions of PLC (Power Line Communication) and multi-rate, maximum demand and event log. It consists of a special metering unit, data processing unit and memory unit, It can measure power, voltage, current, demand, load and set up 4 Multi-rate, 4 time zone, 80 time of period and holiday. The performance of meter is compatible with ANSI C12.1.
Introduction: Features of the CMR (Characteristics of automatic meter reading system)
1.1 Obvious control of the line loss
In a normal condition of a power line, the line loss of a transformer is not included in a Distribution-Transformer-District (DTD). The loss can be controlled within 3% - 5%. If the loss is more than the value, it means there must be an electricity leakage or/and tamper in the DTD.
The most methods of tamper can not be used in our PLC electronic meter and the power losses can be reduced largely. In addition, a computer in a master station monitors the operation of all meters in a DTD and this provides utilities a necessary inspection to meters, which is deterrent to those tampers. There is a significant benefit to utilities, usually a 5% - 10% increase of income of a utility, according to a statistic of most DTD where the system is running.
1.2 The basic meter data can be collected by and recorded in the computer at a master station for utilities analyzing power consumption and achieving a best power management by computer in whole process. With social development it is a trend that centralized meter-reading (CMR) will alternate the manual meter-reading. The use of CMR will bring benefits and also a revolution in the management of meter-reading.
1.3 The CMR system provides utilities an accurate, timely and reliable meter-reading for power charging
The components of the CMR System
Our CMR system (PLC) consists of a data-collecting unit, a centralized data-collecting & processing unit at a DTD, a computer with software of meter-reading management at master station and communications unit.
2.1 Data-collecting unit (build-in in an electronic wave-carrier meter)
The unit is a PCB assembly module integrated metering, data collecting and transmission. It makes the meter as an electronic watt-hour meter with PLC communication capacity. Due to the use of duplex communication for response, it achieves a two-way communication through power line among all other units; thereby the meter has the ability to relay each other and extends the communication distance.
2.2 Data-collecting & centralized processing unit for a Distribution-Transformer-District (refer as Intelligent Concentrator)
One single unit is installed at a fixed place in each DTD and controls 1000 wave-carrier meters. A concentrator automatically read all meters installed in a DTD timely, which is controlled by a computer in master station, and it has the features of self-learning and self-adaptive to a power grid structure.
The concentrator communicates, sends instructions and receives data through a low-voltage power line (downlink channel), and communicates with a computer in master station through an uplink channel. The technology of Communication through a Low-voltage power line is a key technology in our system and meters. With the progress and development on the technology, it has matured to use popular in a reliable data transmission. Presently, the uplink channels are phone line, GPRS, radio or 485-bus (the uplink channel in a distribution network automation system) and so on.
2.3 A meter-reading management software and a communication unit (referred as "A Background") in the master station
The software of meter-reading and management is installed in the computers of the master stations of utilities.
The software includes a database-managing module, a network-connecting module, remote setting module, remote meter-reading module, real-time monitoring module and unmanned on-duty module. Administrator can operate a remote concentrator by a computer in the master station, and start a concentrator into meter-reading mode of an unattended on-duty and automatic data-reading timely from a concentrator. The software automatically extracts the characteristics of electricity users, analyze the data and report all suspicious situations.
The administrator starts a real-time monitoring function and makes a real-time monitoring on the operation of those suspicious meters.