Question

You're the operator of a 1.70

Answer 1

The kVA laod as given would be:

kW/power factor = 6.1 MW / 0.93 = 6.56 MVA

Total current then would be 6,559,140 VA / (18,000*1.731) = 210.4 amps. This assumes a three phase source since at 6.56 MVA it is not likely it would be single phase.

If it was the total current would be 6.56 MVA / 0.018MV = 364.4 Amps as you have stated.

I will stick with single phase because you assumed it or know it to be the case.

So we know the we have 6.56 MVA @ arccos(0.93) degrees = 6.56 MAV @ 21.57 degrees.

Convert this number to Rectangular notation:

6.56 MVA @ 21.57 degrees = 6.56 MVA*Cosine (21.57) +j 6.56 MVA*Sine (21.57) =

6.10 MW + j 2.41 MVAR, I assummed a lagging power factor since you stated you will be correcting it with capacitors. So to correct to a power factor of 1.0 you must add exactly the same number of MVARS of capacitance or -j 2.41 MVAR

To get: 6.10MW+j2.41 MVAR -j2.41 MVAR = 6.10 MW +j0 = 6.10 VA 2 0 degrees = 6.10 MW.

The station will be delivering exactly the same amount of "POWER" but you should notice that teh MVA value decreased from 6.56 MVA @ 21.57 degrees to 6.10 MVA @ 0.0 degrees. The affect of correcting the power factor does notchange the power delivered but does change the MVA by reducing teh power factor angle to zero.