Electric Energy Meter Knowledge
An electric energy meter, commonly known as a watt-hour meter, is an instrument that measures the electric energy consumed by electrical appliances.
Divided by principle: Electric energy meters are divided into two categories: inductive and electronic.
Power phase classification: there are single-phase electricity meters, three-phase electricity meters.
The mechanical electric energy meter uses the eddy current generated by the voltage and current coils on the aluminum plate to interact with the alternating magnetic flux to generate electromagnetic force to make the aluminum plate rotate. At the same time, the braking torque is introduced, so that the speed of the aluminum disc is inversely proportional to the load power. Through the rotation of the axial gear, the electric energy is measured by accumulating the number of revolutions of the turntable by the counter. Therefore, the main structure of the watt-hour meter is composed of a voltage coil, a current coil, a turntable, a rotating shaft, a braking magnet, a gear, and a meter.
The electronic energy meter is composed of a current transformer, an integrated metering chip, a microprocessor, a temperature compensation real-time clock, a data interface device, and a human-machine interface device. The integrated metering chip converts the analog signal from the voltage divider and the current transformer into a digital signal, and performs the digital integral operation on it, so as to obtain the active power and reactive power accurately. The microprocessor processes the data according to the corresponding tariff and demand requirements. The result is stored in the data memory and provides information and data exchange to the external interface at any time.
Our country's electric energy meter naming rules:
1st place: D means electric energy meter
2nd place: D means single-phase, T means three-phase four-wire, S means three-phase three-wire.
3rd place: S means electronic
4th place: D means multi-function meter, F means multi-rate (time-sharing), and Y means prepaid.
The specifications can be divided into a three-phase three-wire system, a three-phase four-wire system, single-phase system.
From the wiring method, it can be divided into access types through the transformer and direct access types.
From the measurement accuracy, it can be divided into 0.2S level, 0.5S level, 0.5 level, 1.0 level, 2.0 level.
