Innovative Communication for Power Lines
Power Line Communication (PLC) is grounded on the principle of carrying data over conductors through which simultaneously ELECTRICITY is distributed. The aim is to provide data transfer at every point on the power line without needing a new cable or wireless solutions. Although it may seem like a new technology, its foundations date back to 1838.
History of Power Line Communication
The first study based on Power Line Communication was carried out by EDWARD DAVY in 1838 on a remote readable electric meter design to control the voltage levels of the Liverpool telegraph company’s batteries installed in some of London’s sparsely-populated areas. The first patents about PLC systems were filed in England in 1897 and in Germany in 1901.
In 1954, AIEE (the American Institute of Electrical Engineers) published a guideline about channels and applications for power line communications. This guideline increased the number of studies on PLC.
In the 1960s, the productions of transistors started. In the 1970s, it was foreseen that some other functions beyond charging electricity, water, and gas consumption could also be conducted in the near future. These include preventing automatically the subscribers who does not pay his/her bill from receiving the service in question, sharing briefly important news with the subscribers, and the idea of sharing any disasters or accidents.
The beginning of price decreases in computers in the 1990s also brought along the subject of forming Local Area Networks (LAN) on the power line.
In the 2000s, the spread of computers at home and the formation of home networks became a target market for the information technology (IT) sector. PLC has become an ideal tool for building home computer networks for home automation. These years are also the periods when the world’s energy problems and the global warming is discussed and the concept of “Smart Grid” emerged. The fact that PLC has remarkable advantages in SMART GRID communication infrastructure has increased the studies on PLC again.
Meter Automation Systems through Power Line Communications
In our country, meter automation projects started to gain importance especially in the 2000s and to be applied with the impact of large buildings (Mass Housing, Residence, Shopping Mall). Although these applications were usually made by cable, it was attempted to be make them through fiber optics for longer ranges, or through GPRS for even longer ranges. Although radio frequency-based infrastructures (LoRa, Sigfox, etc.) are particularly used in mechanical meter automation, along with the privatization of distribution companies, GPRS infrastructure stands out in electricity meter automation.
The need for a new cabling network in these infrastructures, increasing operational costs, or dependency on different companies (GSM operators) have engendered search for alternatives.
As in the first study based on Power Line Communication, it did not take long in Turkey to meet with METER AUTOMATION, and in the last five years, approximately one million electricity meters have been read and controlled remotely with PLC infrastructure.
The first step to follow when installing a Meter Automation System to communicate over the PLC is realized by connecting a Data Concentrator Unit (DCU) to the output of the distribution transformer (secondary).
Although DCU is generally thought as a simple modem, it is an advanced device including a mini PC and an operating system and providing communication between the softwares at the center and the meters.
DCU provides communication by printing signals at different frequencies on the network with counters with appropriate communication modules for the PLC under the Distribution Transformer to which it is connected. The collected data are transmitted to the HES (Head End System) software in the center via a 4.5g or Ethernet connection. In the same way, instant meter reading requests from the center, meter energy on/off orders, or date/time synchronization operations are carried out with the same logic through the DCU.
The collected data are transferred via web service applications to MDM (Meter Data Management) and 3rd party softwares. In this way, web pages can be designed for loss/leakage monitoring reports on a transformer basis; detection of irregular interventions to the meters (magnetic field application, opening the terminal cover, detection of neutral leaks, etc.); and online monitoring of the consumption of end users.