What is the cause of transformer loss?

PUBLISHER:Shanghai Moye Electric Co.,Ltd　RELEASE TIME:2017/7/13

When the primary winding of the transformer is energized, the coil magnetic flux generated in the core flow, because the core itself is a conductor, in the plane perpendicular to the magnetic field lines will be induced potential, the potential in the core section to form a closed loop and a current p like a vortex so called "vortex". This "eddy current" increases the loss of the transformer and causes the iron core of the transformer to be heated and the temperature rise of the transformer increases. The losses caused by eddy currents are called iron losses". In addition to the winding of transformer is the need for a large number of copper wire, the copper wire has resistance, current flows through the resistor will consume some power, this part of the loss often becomes the heat consumption, we call this "loss of copper loss". Therefore, the temperature rise of the transformer is mainly caused by iron loss and copper loss. It can be seen from the measurement that the transformer has 4 windings and is the shielding terminal. For Buck type power transformers, the primary winding has smaller diameter and more turns than the secondary winding. Thus, a buck transformer such as Fig. 4, whose resistance is the largest, is the primary winding. The third step: to determine the voltage of all secondary windings. Because the transformer has iron and copper losses, so its output power is always less than the input power, so we introduce a parameter to describe the efficiency, ETA = power output / input power.
A. voltage ratio:
Two groups of transformer coil number is N1 and N2 respectively, N1 N2 as primary, secondary. With an AC voltage in the primary coil, the induced electromotive force generated in the secondary coil will be. When N2>N1, the voltage induced electromotive force is still high, the transformer is called a step-up transformer: when the N2 U1/U2=N1/N2 type N called the voltage ratio (ratio of the number of rings). When n<1, N1>N2, U1>U2, the transformer step-down transformer. Otherwise it is a step-up transformer. Otherwise the current electric power than I1/I2=N2/N1 P1=P pay attention to the above formula only in an ideal transformer only one side coil set when there are two side coil P1=P2 P3, U1/N1=U2/N2=U3/N3, the relationship between current must use electrical power to ask, there are multiple classes and so on
Efficiency of B. transformers:
At the rated power, the ratio of the transformer output power and input power, called the efficiency of the transformer, namely ETA = (P2 / P1) x100% type ETA for transformer efficiency; P1 power input, P2 output power. When the output power of P2 transformer is equal to the input power of P1, the efficiency is equal to 100% the transformer will not produce any loss. But in fact this is not the transformer. The transformer to produce the total loss of power transmission, such losses are mainly copper loss and iron loss. Transformer copper loss is the loss caused by the coil resistance. When the current through the coil resistance heating, a part of the electrical energy into heat and loss. And as the general coil wound by copper wire with insulation, so called copper loss. Transformer iron loss consists of two aspects. One is the hysteresis loss, the internal friction between the molecular film, heat energy, and thus a loss Part of the electric power, this is the hysteresis loss. Another is the eddy current loss, when the transformer iron core. The magnetic force line in the plane and vertical lines through the induced current, due to this current into a closed loop formed from the circulation, and into a spiral shape, so called eddy. The existence of vortex core heat and the consumption of energy, this loss is called eddy current loss.