Offering a range of AMR alternatives
New technologies in the electricity industry are introducing possibilities that were unthinkable just a few years ago. In the metering field, these are reflected in the shift from electromechanical to electronic meters, as well as the development of different communication technologies.
The improvements in communication technologies inside the meter offer several benefits to utilities – the ability to establish customers’ actual consumption; to avoid human billing errors; to control technical and nontechnical losses; to control load profiles and predict peak consumption; to offer customers different tariffs; and to connect or disconnect customers remotely. The customer also benefits – no more estimated bills; no need to pay huge bills when the meter is finally read; different tariffs in deregulated markets; Internet access to check consumption, and so on.
CIRCUTOR offers a family of multifunction energy meters – the CIRWATT range – capable of satisfying the most demanding requirements of energy measurement systems. Their main feature is that they can be used with several different communication systems, giving both utilities and end customers a wide range of AMR alternatives.
CIRCUTOR meters have one optical port and one or two communication ports. The high accuracy meters have two serial ports, and the others have one; these serial ports can be either RS232 or RS485. These communications channels allow meter information to be transferred directly to a PC (RS232) or transferred from different meters connected in an RS485 network to the PC.
One feature that has been added to the CIRWATT meter family is Ethernet communication, which gives customers high added value, because the existing network (computer network) is used and there is no need for extra wiring. The meter itself contains the Ethernet port, so a new converter device (TCP2RS) is not needed. The communication request speed from the software to the devices is faster, because the existing network is being used. This system allows the connection of different devices located in different places, and all the meters connected to the Ethernet network can be read from one central computer.
MODEM COMMUNICATIONS (RTC/PSTN/GSM/GPRS)
Another type of data transfer system is modem communications. This is used when equipment is connected in a remote location, where it is not possible to install a communications cable near the PC. The modem can be RTC/PSTN (analogue) or GSM/GPRS. This AMR system is used for meters that are difficult to access, and saves the utility both time and money.
However CIRCUTOR has committed to PLC (Power line carrier). Our aim is that the cost of the PLC technology should be similar to other cheap AMR systems, but with more reliability, effectiveness and features.
POWER LINE COMMUNICATIONS
The PLC system reading the CIRWATT meters is in the narrow band PLC (in other words in the low voltage system). All meters with PLC communication connected to the same substation send all the information (energy consumed, events, load profile, alarms, etc) to the data concentrator unit (PLC concentrator) located in the low voltage substation. The PLC concentrator stores all the data from every meter, and it is read by central PC via Internet, GSM/GPRS, Ethernet or using fibre-optics and converters.
The main features of the system are its ‘plug and play’ capability, a repeater function, and the fact that it is both robust and secure. The meters connected or added to the system are automatically detected by the concentrator, and every meter can act as a repeater of the signal, allowing distant meters to be read.
Another advantage of the system is substation loss management. Locating three-phase PLC equipment at the head of a distribution system allows it to calculate technical and non-technical losses, obtain the total consumption of the meters connected to a particular substation, and make a comparison between the total consumption of the meters and the power registered on the three-phase meter.
CIRCUTOR has also developed PLC meters with an internal power limiter, which allows them to be programmed with different hourly slots and contracted power. When the customer exceeds the contracted power, the power supply of the meter is automatically cut off via PLC. In this way correct power limiting is achieved safely.
Looking ahead, we believe that utilities will no longer employ a single AMR technology. Instead different technologies will co-exist, depending on the location, number of customers, type of customers (industrial or domestic), coverage, location and distance, etc. For this reason CIRCUTOR is offering different AMR solutions, even if this sometimes involves customisation of the meter for a particular application and market.