Working Principle Of Electric Energy Meter

When the electric energy meter is connected to the circuit under test, alternating current flows through the current coil and the voltage coil, and the two alternating currents generate alternating magnetic fluxes in their iron cores respectively. The alternating magnetic flux passes through the aluminum disk, inducing eddy currents in the aluminum disk. The eddy current is acted by the force in the magnetic field, so that the aluminum plate gets torque (active torque) and rotates. The greater the power consumed by the load, the greater the current passing through the current coil, the greater the eddy current induced in the aluminum plate, and the greater the torque that makes the aluminum plate rotate. That is, the magnitude of the torque is proportional to the power consumed by the load. The greater the power, the greater the torque, and the faster the aluminum disc turns. When the aluminum disc rotates, it is acted by the braking torque generated by the permanent magnet, and the braking torque is opposite to the active torque. The magnitude of the braking torque is proportional to the rotational speed of the aluminum disc. The faster the aluminum disc rotates, the greater the braking torque. When the active torque and the braking torque reach a temporary balance, the aluminum disc will rotate at a constant speed. The electrical energy consumed by the load is proportional to the number of revolutions of the aluminum disc. When the aluminum plate rotates, it drives the counter to indicate the power consumption. This is the simple process of how the energy meter works.