Among the transformer losses there are iron losses, copper losses, hysteresis losses, eddy current losses, stray losses, dielectric losses, and other types of losses. In transformers, hysteresis losses are caused by changes in the magnetic field of the transformer core, whereas copper losses are caused by the resistance of the transformer windings.
There are six types of losses that can occur when a transformer is operating:
1.There is a loss in the iron core that occurs when the coil is energized, causing the magnetic lines of force in the core to alternate, creating eddy currents and hysteresis losses in the core. This loss is collectively referred to as iron loss.
2.When the primary coil and secondary coil of a transformer are energized, power loss will occur as a result of the resistance in the coil itself. This type of loss is called copper loss. It occurs when there is a current passing through the primary coil and secondary coil of the transformer. It can be said that transformer losses are the sum of iron loss and copper loss, and these losses are correlated with the capacity, voltage, and usage of the transformer.
3.An eddy current loss occurs when the magnetic flux is connected to a closed circuit and an electromotive force is induced in the circuit. The current value is determined by the amount of electromotive force around the circuit and the resistance of the circuit.
These EMFs circulate an electrical current within the material’s body due to its conductive core. Eddy currents are these circulating currents. When a conductor experiences a changing magnetic field, they occur. Due to the fact that these currents are not performing any useful work, they create eddy current losses (I2R losses) in the magnetic material. By using thin lamination for the core, eddy current losses can be minimized.
Eddy current loss can be expressed as follows:
The following:
K e-Coefficient of eddy currents. A magnetic material’s value is determined by its properties, including its volume and resistivity, as well as its thickness and lamination
B m-Flux density at its maximum,the unit is wb/m 2
T-The laminate’s thickness,the unit is m
F-Reversal frequency of magnetic fields,the unit is Hz
V-Magnetic material volume,the unit is m 3
4.Transformer windings have an ohmic resistance, which causes copper losses or ohmic losses. It is assumed that I1 and I2 are primary and secondary currents, respectively. If R1 and R2 are the resistances of the primary and secondary windings, then the copper losses occurring in the primary and secondary windings respectively will be l12R1 and l22R2, respectively.
As a result, the total loss of copper will be as follows:
Losses that vary according to load are also called variable losses. Load current squared determines copper loss.
5.Loss of credibility
Leakage fields cause stray losses. In comparison with iron and copper losses, these losses are very small and can be ignored.
6.Loss of dielectric properties
Transformer insulation or transformer oil solid insulation can cause dielectric losses. The efficiency of the transformer will decrease if the oil deteriorates, the solid insulation is damaged, or the quality of the oil deteriorates.
