per unit conversion

Thread Starter

almotions

Joined Feb 6, 2009
46
Hi all,
assuming a three-phase supply (25k Vrms phase-phase) supplying a three-phase load. I connected a voltage and current measurement block having a base voltage of (25k Vrms phase-phase) and base power of
(1M VA 3 phase). With the pu voltage and current measurements into a active and reactive power measurement block,the output of the power measurement block must be multiplied by a gain of 2/3 in order to have the correct active and reactive power measurement.My question is why 2/3?
All these are simulated in SIMULINK/MATLAB.Thanks..


Regards,
alvin
 

lmartinez

Joined Mar 8, 2009
224
Provide a oneline diagram of the power system being analyzed? It will visually help us provide more detail assistance to your question.........
 

Duane P Wetick

Joined Apr 23, 2009
440
If each phase feeds 2 loads, and the loads are then split between the other two phases, then the system is considered balanced. (assuming the load VA's are the same.) You don't have to worry about the vectored relationships if all are equal, just simple math will suffice.

Cheers, DPW
 
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