What Are the Working Principles and Classifications of Watt-Hour Meters?
The watt-hour meter is also called an electric energy meter, which refers to an instrument that measures various electrical quantities. With the rapid development of my country's economy, the demand for electricity in all walks of life is increasing, and the phenomenon of unbalanced electricity consumption at different times is becoming more and more serious. In order to alleviate the increasingly acute contradiction between power supply and demand in my country, adjust the load curve, and improve the phenomenon of unbalanced power consumption, fully implement the peak, flat, and valley time-of-use electricity price system, cut peaks and fill valleys, improve the national electricity efficiency, and make rational use of electricity. resource. Today, electricity meters are used in every aspect of our lives. Let us introduce the working principle and classification of the watt-hour meter.
1. What is the working principle of the watt-hour 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 affected by the braking torque generated by the permanent magnet. 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 higher the braking torque. bigger. 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.
2. What are the classifications of commonly used electric energy meters?
(1) Electric energy meters can be divided into DC electric energy meters and AC electric energy meters according to the circuits they use. AC electric energy meters can be divided into single-phase electric energy meters, three-phase three-wire electric energy meters, and three-phase four-wire electric energy meters according to their phase lines.
(2) Electric energy meters can be divided into electrical-mechanical electric energy meters and electronic electric energy meters (also known as static electric energy meters, or solid-state electric energy meters) according to their working principles. Electromechanical electric energy meters are used in AC circuits as ordinary electric energy measuring instruments, and the most commonly used ones are inductive electric energy meters. Electronic energy meters can be divided into fully electronic energy meters and electromechanical energy meters.
(3) Electric energy meters can be divided into integral electric energy meters and split electric energy meters according to their structure.
(4) Electric energy meters can be divided into active electric energy meters, reactive electric energy meters, maximum demand meters, standard electric energy meters, multi-rate time-sharing electric energy meters, prepaid electric energy meters, consumption electric energy meters, and multi-functional electric energy meters, etc. according to their uses.
(5) Electric energy meters can be divided into ordinary installation electric energy meters (0.2, 0.5, 1.0, 2.0, 3.0 grades) and portable precision electric energy meters (0.01, 0.02, 0.05, 0.1, 0.2 grades) according to their accuracy levels.
