Three Winding Transformer

[SSLA]

Sometimes records of factory test results for a three winding power transformer are only partially complete. Often the other results are available but the kW figures for the X-Y test are missing . A local rule of thumb that seems to have emerged is:

kW loss X-Y = 0.85 *(kW loss H-X + kW loss H-Y)

How reliable is this guideline when applied to transformers of several different manufacturers in which the winding configuration may not be known?

The result is used to develop a mathmatical model of the transformer which in turn is used to estimate load loss within the transformer under several operating conditions. The loss estimated in added to readings from billing meters installed on the secondary and tertiarty.

 

[GamezBeCJ]

If what you are talking about is Winding or Copper Losses, you do not need the X-Y losses because they are acounted for in the H-X and H-Y tests.