There are two main types of losses in transformers, namely transformer iron loss and transformer copper loss.
Transformer iron loss: mainly refers to the no-load loss of the transformer, which is a constant loss mainly determined by changes in voltage. When the transformer voltage and frequency remain constant, the no-load loss of the transformer remains basically unchanged.
Copper loss of transformer: refers to the short-circuit loss of the transformer, which is the power loss caused by heating when there is current flowing through the transformer winding. Transformer copper loss is a variable loss that is related to the load rate of the transformer. As the load increases, the copper quality also increases. The copper and iron losses of transformers can be obtained by consulting manuals or based on transformer test data. The economic operating point where transformer losses are low is when the load rate is between 0.5 and 0.6, that is, when the iron loss and copper loss of the transformer are equal. It can be determined whether to operate transformers in parallel based on their economic operating point. The power loss of a general transformer can be calculated using the following formula:
△ P=△ P0+(Scp/Sn) * △ Psc where
△ P0=no-load loss of transformer
△ Psc=short-circuit loss of transformer
△ P=total loss of transformer
Scp=average capacity of the transformer
Sn=rated capacity of the transformer
