Electric meters are the core edge intelligent terminal in the modern power grid system, located in the distribution and user access link (the last mile of the power grid). They connect power grid enterprises (power generation/transmission/substation/distribution) and end users (residential/industrial/commercial), undertaking the dual tasks of accurate energy metering and real-time data interaction, and are the basic guarantee for the safe, efficient and intelligent operation of the power grid.
Power Generation
High-voltage Transmission
Low-Voltage Distribution
End Users
Power plant generates electricity.
Transformer converts low voltage electricity to high voltage for efficient transport. Transmission lines carry electricity over long distances.
Zone substation transformer coverts high voltage electricity to low voltage for distribution. Distribution lines carry low voltage electricity to consumers. The meters support users pay for electricity billing.
Homes, offices and factories use electricity for lighting and cooling, and to power appliances.
2. Standard Connection Methods (IEC Compliant)
Physical Wiring (IEC 60364 Standard)
Meter Type
Connection Scheme
Safety Notes
Single-phase (Residential)
L→T1→T2→Load; N→T3→T4→Load; PE to housing
No open circuits; PE not in metering circuit
Three-phase (Industrial)
L1/L2/L3 via CT P1→meter; CT S1/S2→sampling terminals
No short circuits on voltage inputs
Communication Protocols (IEC 62056 Series)
Method
Standard
Scenarios
Advantages
RS485
IEC62056-41
Industrial, grid gateways
High speed, strong anti-interference
PLC
IEC62056-42
Residential areas
No additional wiring needed
NB-loT
3GPP+ IEC62056-1-0
Remote locations
Ultra-low power, wide coverage
3. Working Principle Flowchart
Energy Input
Measurement
Data Processing
Strorage
Transmission
Grid Interaction
User Interface
Electricity from distribution network enters meter via power lines
Internal CT/PT convert current/voltage to measurable signals
Metering chip calculates active/reactive energy consumption
Data saved in non-volatile memory
Upload to grid master station via RS485/PLC/ NB-IoT
Master station sends remote control commands (two-way communication)
