Detailed explanation of the difference between transformer iron loss and copper loss

In the loss of transformer, there are mainly two parts: iron loss and copper loss. Then, what is the difference between iron loss and copper loss of transformer?

The iron loss of the transformer is the loss produced by the iron core in the transformer, and the copper loss of the transformer is a load loss.

1.The iron loss of the transformer

Iron loss, also known as no-load loss, is a fixed loss of the transformer. It is the loss generated by the iron core in the transformer, so it is also called iron core loss.

Iron loss refers to the power consumed by the transformer in the iron core under rated voltage (secondary open circuit), including hysteresis loss and eddy current loss.

Transformer iron losses include:

(1) Hysteresis loss

When the alternating current passes through the transformer, the direction and size of the magnetic lines of force passing through the silicon steel sheet of the transformer change accordingly, causing the molecules inside the silicon steel sheet to rub against each other and release heat energy, thus losing a part of the electrical energy, which is the hysteresis loss.

(2) Eddy current loss

When the transformer is working, there is a magnetic field line passing through the iron core, and an induced current will be generated on a plane perpendicular to the magnetic field line. Because this current forms a closed loop to form a circulating current and is vortex-like, it is called an eddy current.

The existence of eddy current makes the iron core heat up and consumes energy, and this loss is called eddy current loss.

2.Copper loss of transformer

Transformer copper loss, also known as load loss.

Copper loss (short-circuit loss) refers to the sum of energy lost by the primary and secondary currents of the transformer flowing through the coil resistance. Because the coil is mostly made of copper wire, it is called copper loss.

The copper loss of the transformer is proportional to the square of the current. The kilowatts marked on the nameplate refer to the copper loss of the coil passing the rated current at 75°C.

The above is the difference between iron loss and copper loss in voltage transformers. Iron loss is a fixed loss, while copper loss is a load loss. I hope it will help everyone to learn and understand.