The principle of the transformer is based onthe famous law of mutual induction. If the primary winding of this electric machine is included in the AC network, then an alternating current will flow through this winding. This current will create an alternating magnetic flux in the core. This magnetic flux will begin to thread the turns of the secondary winding of the transformer. A variable EMF (electromotive force) will be induced on this winding. If you connect (connect) the secondary winding to some receptacle of electrical energy (for example, to a conventional incandescent lamp), then under the influence of the induced electromotive force on the secondary winding, the electric current will flow to the receiver.
Вместе с этим, по первичной обмотке будет leak current flow. This means that the electricity will be transformed and transferred from the secondary winding to the primary one at the voltage to which the load is designed (that is, the power receiver connected to the secondary network). The principle of the transformer is based on this simple interaction.
To improve the transmission of magnetic flux andstrengthening the magnetic coupling, the winding of the transformer, both primary and secondary, is placed on a special steel magnetic circuit. The windings are isolated from the magnetic circuit, and from each other.
The principle of operation of the transformer is different involtage 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 will be 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 down. However, the same transformer can be used as a step-up, and as a step-down. A step-up transformer is used to transfer energy over various distances, for transit and other things. Lowering is used mainly for the redistribution of electricity between consumers. The calculation of the power transformer is usually made taking into account its subsequent use as a step-down voltage or step-up.
As mentioned above, the principle of operation of the transformer is quite simple. However, there are some curious details in its design.
In three-winding transformers threeinsulated windings are placed on the magnetic core. Such a transformer can receive two different voltages and transmit energy to two groups of electric power receivers at once. In this case, it is said that in addition to the lower and higher voltage windings, the three-winding transformer also has a medium voltage winding.
The windings of the transformer are cylindricalform, and completely isolated from each other. With such a winding, the cross section of the rod will have a round shape to reduce non-magnetised gaps. The smaller such intervals, the smaller the mass of copper, and, consequently, the mass and cost of the transformer.
