LOAD LOSS IN POWER TRANSFORMER

LOAD LOSS IN POWER TRANSFORMER

LOAD LOSS also known as winding loss is similar to the analysis of a transmission line represented by the I squared R formula. Load loss is called this way because the losses here vary with the square of the load current. Higher load means higher loss and lower load means lower loss. In the past, load loss is referred to as copper loss but later this has been corrected since modern transformers now use aluminium windings in substitute for copper. Losses occurring in transformers are mostly load losses, so the maximization of the transformer use with respect to losses is a very vital form of analysis.

To be familiar with transformer loading, one should know that a typical power transformer is assigned with several kVA ratings. At normal condition, with no auxiliary cooling equipment operating, a substation transformer is said to be in its base rating or in its self-cooled (oil and air) rating. However, in actual practice, a power transformer is made to be capable of loadings higher than its self-cooled rating. This higher rating as a percentage of the base is attained through auxiliary cooling equipment like forced air (FA) or forced-oil-and-air (FOA). A 33MVA full rating power transformer for instance with an OA/FA1/FA2 cooling system is said to have a base rating of 20/26/33 MVA. Rating increases in response to the cooling equipment used.
When a substation transformer is use at a rating higher than its base rating, the transformer winding losses are higher than the quoted losses in proportion to the square of its rating increase. To understand more clearly, suppose a transformer operating at 65% above its base rating would dissipate winding losses of (1.65x1.65) or 2.72 times its base winding losses.

In summary of the discussions above, Load loss on a power transformer varies directly to the load current that passes through it. Proper analysis of the allowed load for the transformer to carry is vital especially when an electric utility wishes to minimize the losses that the transformer contributes to the system.

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PARTS OF A POWER TRANSFORMER

What are the name of the basic parts of a Power Transformer? We can not deny the fact that only a handful of electrical engineering students are presently familiar with power transformers especially on what it looks like. Unlike a transformer we found in our homes, a power transformer’s appearance and construction is somewhat more complicated. It is not just a simple winding with a primary and secondary terminal although basically any transformer has one. The function that a power transformer plays in an electrical system is very important that an electric utility can not afford to loss it during its operation. Our discussion here will focus more on the basic parts and functions of a power transformer that are usually tangible whenever you go to a substation . Although not all power transformers are identical, nonetheless they all have the following listed parts in which the way of construction may differ.

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ELECTRIC MOTOR NAMEPLATE SPECIFICATIONS

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