A transformer rated at 100 MVA has how many MVARS flowing through it at a maximum rating?

To determine the number of MVARS (megavolt-amperes reactive) flowing through a transformer rated at 100 MVA at maximum load, we need to understand the concept of power factor and power calculations.

A transformer rated at 100 MVA represents its maximum apparent power capability, which includes both active power (measured in MW) and reactive power (measured in MVAR). The relationship between these values is governed by the formula for apparent power:

[

S^2 = P^2 + Q^2

]

where S is the apparent power in MVA, P is the active power in MW, and Q is the reactive power in MVAR. In cases where the power factor is not specified, a common assumption is to consider a typical power factor, which for many industrial applications might approximate 0.8.

When the power factor is 0.8, the real power (P) can be calculated as:

[

P = S \times \text{power factor}

]

Substituting the values:

[

P = 100 \text{ MVA} \times 0.8 = 80 \text{ MW}

]

Now, to find the reactive power (