An article explaining the working principle of the electricity meter in detail

The concept of electricity meter

The electric energy meter commonly used by electricians is an instrument used to measure electrical energy, commonly known as the watt-hour meter.

How does the electricity meter work?

① Working principle of mechanical electricity meter: When the electric energy meter is connected to the circuit, the magnetic flux generated by the voltage coil and current coil passes through the disk. These magnetic fluxes are out of phase in time and space, and induce eddy currents on the disk respectively. Due to the interaction between magnetic flux and eddy current, the rotational torque is generated to rotate the disc. Due to the braking effect of the magnet, the rotation speed of the disc reaches a uniform motion. Since the magnetic flux is proportional to the voltage and current in the circuit, the disc rotates. Under its action, it moves at a speed proportional to the load current. The rotation of the disc is transmitted to the counter through the worm, and the indication of the counter is the actual electric energy used in the circuit.

②Basic principles of electronic watt-hour meters: Electronic watt-hour meters use electronic circuits/chips to measure electrical energy; use voltage divider resistors or voltage transformers to convert voltage signals into small signals that can be used for electronic measurement, and use shunts or current transformers to The converter converts the current signal into a small signal that can be used for electronic measurement. It uses a dedicated electric energy measurement chip to perform analog or digital multiplication of the converted voltage and current signals, accumulates the electric energy, and then outputs a pulse signal with a frequency proportional to the electric energy. ;The pulse signal drives the stepper motor to drive the mechanical scale display, or it is sent to the microcomputer for processing and digital display.