Introduction to Transformer Load Loss from the Perspective of Transformer Selection
The load loss of a transformer is an important parameter in transformer parameters. Therefore, in order to help users better understand this parameter, we will introduce it today, focusing on its meaning and characteristics. We will also provide some simple examples. If you do not have a better understanding, please contact us online
The following is the main text:
1. Definition of transformer load loss: When it comes to transformer load loss, it should actually be called short-circuit load loss. The reason for this name is related to the measurement method of transformer loss in our reality. When measuring the load loss of a pair of windings, we short-circuit one winding (if there are other windings, it is open circuit), and apply a voltage of rated frequency and approximate sine wave to the other winding, so that both windings pass through the rated current (or tap current), and measure the power absorbed at the reference temperature. Due to the use of winding short circuit method in measuring losses, it is also known as short-circuit load loss corresponding to load current. For a double winding transformer, there is only one combination of windings, corresponding to a load current with a load loss value.
For example, the short-circuit loss at rated current can be referred to as the rated load loss of the transformer. For multi winding transformers, there are multiple load loss values corresponding to the combination of multiple pairs of windings.
Next, let's introduce the characteristics of transformer losses
Load loss includes two parts: DC resistance loss (PR) and stray loss of the winding. Stray losses include eddy current losses in wires, circulating current losses between parallel wires, and eddy current and circulating current losses in structural components such as iron core clamps and pull plates, winding pressure nails, and steel pressure plate oil tank covers, walls, and bottoms. Therefore, load losses are related to the following factors.
(1) Wire material: divided into aluminum wire, soft copper wire, semi-rigid copper wire, etc.
(2) Wire shape: divided into circular wire, flat wire, composite wire, and transposed wire, etc.
The selected current density and transposition method, as well as the type of winding and the material of its components, are divided into permeable steel and low magnetic conductivity steel
(3) Shielding methods: divided into magnetic shielding and electromagnetic shielding.
The total loss of a transformer is the sum of no-load loss and load loss, including auxiliary losses such as submersible pumps and fans. At rated load, the load loss accounts for about 80% of the total loss and plays a decisive role in the efficiency of the transformer.
