Spin Up #2-15

[dray]

I think this should be easy but for some reason I can't remember how to do this.

Generator A has a capacity of 3MVA with an impedance of 3%, generator B has a capacity of 4MVA with an impedance of 2%. Gen A&B are syncronized and operating in parallel. What is the max load Gen B can handle in this configuration without overloading an generators? Thanks.

 

[Power12]

I think this should be easy but for some reason I can't remember how to do this.

Generator A has a capacity of 3MVA with an impedance of 3%, generator B has a capacity of 4MVA with an impedance of 2%. Gen A&B are syncronized and operating in parallel. What is the max load Gen B can handle in this configuration without overloading an generators? Thanks.

It is in the other thread at http://engineerboards.com/index.php?showtopic=18311

I also pasted it below

For these type of problems I use the trial and error method. I multiply the generator MVA by the other generators impedance.

SA = 2 times 3 = 6

SB = 3 times 4 = 12

Then I see SA is equal to half of SB

Since Gen B has a max load of 4MVA, therefore Gen A is half of 4 MVA which equals 2MVA

So MVAL = SA + SB = 2MVA + 4 MVA = 6MVA

 

[robertplant22]

How come you do not need to convert one of the generators impedances to a new base, so that both generators have the same base impedances?

This approach is very simplistic and I like it, I'd like to have a little background on it though.