Question

A 50 Hz, 100 kVA, single-phase transformer supplied with 2.5 kV has a turns ratio of 32 to 8. Primary and secondary resistances are 0.2 ohm and 0.009 ohm respectively and the corresponding leakage reactances are 2.1 ohm and 0.052 ohm each. Determine the equivalent resistance R_eq referred to the secondary side. Show the numerical answer rounded to 3 decimals in ohm, but don't show the unit. Answers must use a point and not a comma, eg. 1.457 and not 1,457.

Answer 1

The equivalent resistance R_eq referred to the secondary side can be found by adding the primary and secondary resistances and multiplying them by the square of the turns ratio. In this case, the equivalent resistance is 3.192 ohm.

Step-by-step explanation:

To find the equivalent resistance R_eq referred to the secondary side, we need to consider the primary and secondary resistances, as well as the primary and secondary leakage reactances. The equivalent resistance is determined by adding the primary resistance and the secondary resistance, referred to the secondary side using the turns ratio. In this case, the turns ratio is 32:8, which means there are 32 turns in the primary winding for every 8 turns in the secondary winding. Therefore, to find R_eq, we can use the following formula:

R_eq = (Primary Resistance + Secondary Resistance) * (Turns Ratio)^2

Substituting the given values into the equation:

R_eq = (0.2 + 0.009) * (32/8)^2

Simplifying the equation:

R_eq = 3.192 ohm

Therefore, the equivalent resistance R_eq referred to the secondary side is 3.192 ohm.