How to select a transformer based on its no-load current and no-load loss?

How to select a transformer based on its no-load current and no-load loss?

In the previous section, we explained the characteristics and meanings of no-load current and no-load loss to provide a reference for reasonable selection. Regarding parameter selection, each manufacturer will provide a detailed list of specific parameters. If the manufacturer does not provide this information, users can ask the transformer manufacturer for details. Our company provides detailed explanations during sales, and we have also published the parameters of various transformer specifications online.

Therefore, we will mainly discuss the precautions for selection here:

(1) The core excitation current cannot be only a fraction of the winding’s rated current. We have explained this before; the current measurement method is not accurate. Defining no-load current and no-load loss as transformer performance parameters according to the current standard measurement method has neither physical nor practical significance.

(2) Although silicon steel sheets have excellent magnetic permeability, which can reduce no-load current and no-load loss, it is unnecessary to require excessively high values. The reason is that silicon steel sheets with particularly high magnetic permeability have poor stability of magnetic permeability and may also have a relatively high noise level.

(3) The processes of direct core seam and through-bolt fastening with drilled holes have been eliminated for more than 30 years. Nowadays, it is unnecessary to raise the requirements of slanted joints and holeless binding when ordering transformers. On the contrary, it may affect the further development of core manufacturing process.