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Are these two CURRENT LIMITING REACTOR circuits modeled the same ?

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bdn2004

Electrical
Jan 27, 2007
794
I'm looking at two different models of the same system. They should be alike, but they certainly aren't modeled alike.

On model 1: the Reactor is shown as 83 MVA, 3200A, Positive Sequence Impedance: 0.03 + 4.38j PU and this corresponds to a 0.0984 ohm impedance.
On model 2: the Reactor is shown as a 295 kVA, 1000A, Positive Sequence Impedance: 0.0001 + j0.0044j PU and also corresponds to a 0.0984 ohm impedance.

I know Ohms = Z% x [(kV)^2 * 10/]/kVA

The base MVA is 100 MVA, the system operating voltage is 15kV.
 
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The two reactors are different MVA ratings, so the pu impedances given are likely on different bases. To compute ohmic impedance, you have to use the base MVA that the per unit impedance was calculated on. Similar to transformers. Also, the X/R ratios are likely not the same.
 
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