The principle of the transformer is based on the famous law of mutual induction. If the primary winding of this electrical machine is connected to the alternating current network, then alternating current will begin to flow through this winding. This current will create an alternating magnetic flux in the core. This magnetic flux will begin to penetrate the turns of the secondary winding of the transformer. A variable EMF (electromotive force) will be induced on this winding. If you connect (close) the secondary winding to some kind of electrical energy receiver (for example, to an ordinary incandescent lamp), then under the influence of an induced electromotive force, an alternating current will flow through the secondary winding to the receiver.
At the same time, the load current will flow through the primary winding. This means that electricity will be transformed and transferred from the secondary winding to the primary at the voltage for which the load is designed (that is, the power receiver connected to the secondary network). The principle of operation of the transformer is based on this simple interaction.
To improve the transmission of magnetic flux and strengthen the magnetic coupling windingtransformer, both primary and secondary, is placed on a special steel magnetic circuit. The windings are isolated from both the magnetic circuit and from each other.
The principle of operation of the transformer is different in terms of the voltage of the windings. If the voltage of the secondary and primary windings is the same, then the transformation ratio will be equal to one, and then the transformer itself is lost as a voltage converter in the network. Separate step-down and step-up transformers. If the primary voltage is less than the secondary, then such an electrical device will be called a step-up transformer. If the secondary is less, then lowering. However, the same transformer can be used as both step-up and step-down. A step-up transformer is used to transmit energy over various distances, for transit and other things. Reducing are used mainly for the redistribution of electricity between consumers. The calculation of a power transformer is usually made taking into account its subsequent use as a step-down or step-up voltage.
As mentioned above, the principle of the transformer is quite simple. However, there are some curious details in its design.
In three-winding transformers, three insulated windings are placed on a magnetic circuit. Such a transformer can receive two different voltages and transmit energy to two groups of electricity receivers at once. In this case, they say that in addition to the windingslow and high voltage, the three-winding transformer also has a medium voltage winding.
The windings of the transformer are cylindrical in shape and completely insulated from each other. With such a winding, the cross section of the rod will have a round shape to reduce non-magnetized gaps. The smaller such gaps, the smaller the mass of copper, and, consequently, the mass and cost of the transformer.
