Complementarity! The development of communication mode and the potential of smart meters

 Smart meters, which basic function is metering, according to the developement of smart grid and market application demand derive many functions. Especially the two-way communication function is the soul of smart grid digitalization, refinement, and intelligent management, which gives the meter more missions through communication carriers allows humans and smart meters to interact with information, such as seting parameters, reading power consumption data, reporting event alarms, issuing control commands, and upgrading firmware.

Smart meters’ communication methods can be divided into two categories: WAN and LAN.

1. WAN mode refers to the communication method used by smart meters to directly interact with the system platform for data interaction, including GPRS, NB-IOT, WiFi, Ethernet, optical fiber, etc.

1.1. GPRS communication: GPRS communication, the most used communication method by smart meters, which uses communication operator base stations for data transmission, with a transmission rate of 56Kbps-115Kbps. In service condition, users can send commands in any time, and smart meters will respond in real time. GPRS communication use SIM cards, which issued by communication operators, and charge according to the traffic used. In general, GPRS communication has high reliability but with operating costs. 1.2. NB-IoT communication: NB-IoT (Narrow Band Internet of Things) communication, which uses communication operator base stations for data transmission, with the advantage of strong signal, low speed, low power consumption.In service condition, it needs to be activated to communicate, usually in a dormant state. NB-IoT communication use NB cards, which issued by communication operators, and charge according to the number of times used. 1.3. WiFi, Ethernet, optical fiber communication: They are the internet network communication, with fast transmission rate. The premise is that at the smart energy meter installation place should have internet work.

 

2.LAN mode refers to the data connection between the communication method used by the smart meter and the centralized controller, and then the centralized controller interacts with the system platform through the communication mode of the WAN class, including PLC, LoRa, Zigbee, etc.

 

2.1. PLC communication: PLC (power line carrier) communication,which uses existing power lines to transmit analog or digital signalsat high speed through carrier waves.At present, G3-PLC is commonly used in smart meters,which conforms to the power line carrier communication of G3 standard. HPLC is broadband carrier communication. In general, the advantages of PLC communication are easy installation,no need to re-erect the network, as long as there are power lines, data transmission can be carried out. And the disadvantage is that the communication capacity will be interfered with by the quality of the grid. 2.2. LoRa communication: LoRa communication is a wireless modulation method, which uses the public wireless frequency bands allowed by various countries, common 470MHz, 868MHz, 915MHz, etc., and the communication distance can be 3-10 kilometers. The advantages of LoRa communication are long communication distance, strong anti-interference ability, and low power consumption, which is very suitable for the smart meters. 2.3. Zigbee communication: Zigbee is a low-speed short-distance wireless network protocol, based on cellular connection, communication frequency band 2.4GHz. The LAN communication methods used by smart meters are also RF, WiFine, Bluetooth, etc.

In order to adapt to different installation environments and communication requirements of different countries, smart meters will use a variety of communication methods; When we develop and design, the communication module is easily replaced in the field, hot-swappable and safely isolated. Smart meters transmit data to the system platform in real time through communication functions, which provides a basis for data analysis for the improvement of electricity quality and the development of smart grid, and guides the direction of improvement.