Transformer Example Problem

From Class Wiki
Jump to navigation Jump to search
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.

Kevin Starkey EMEC, Nick Christman, Aric Vyhmeister


Problem:

A step down transformer has a winding of turns. (a) If the input voltage is 1200V, what is the resulting output voltage? (b) If the input and output currents are , respectively, what is the current loss due to the leakage inductance, .

Figure 1: Model for an ideal transformer.
Figure 2: Magnetic circuit of an ideal transformer.


Solution:

a) By modifying equation 5-39 (Mohan 5-22) we can obtain an equation for the output voltage. That is,

.


With the information provided we can now determine the output voltage:


b) From the figure above, we need to find the true value of current (i.e. the current that is not lost by leakage inductance). To accomplish this we will use equation 5-40 (Mohan 5-23) to obtain the value of . That is,

.

Now from equation 5-42 (Mohan 5-23) we can obtain the current loss due to the leakage inductance, which is

.

Therefore, the current loss in our transformer is , which means this specific transformer is very "leaky."