mismatch power measurement in 3 phase PU power and actual power. I am using 3 phase instantaneous measurement block.

I referred to your paper title, "Enhanced Instantaneous Power Theory for Control of Grid Connected Voltage Sourced Converters Under Unbalanced Conditions". I am getting exact instantaneous active and reactive power with marginal deviation i measured using pu voltage and pu current. but when i calculated it by actual voltage and actual current, it is giving instantaneous active and reactive power exactly 1/3 the expected power. I am using 3phase instantaneous power measurement block in MATLAB SIMULINK. if i take base value S=VLL*ILL, it is giving active and reactive power close to expected value but significant variation (i.e. Pout=9700W and Qout=2317 var; Expected output, P=10000W and Q=2500 var) .Please Suggest me the modification. Hope i will hear from you soon.

Answer 1

[Sabin]

It sounds like the discrepancy arises from the use of per-unit values versus actual quantities and the choice of base values in your calculations. In per-unit systems, active and reactive powers are normalized by the base power, so double check for consistency between measurement and calculation. The 1/3 discrepancy suggests a possible issue with phase-to-neutral vs. phase-to-phase voltage usage.

To get more help from the community would be better to attach a model.