Orientation of “Three-Phase V-I Measurement” block and direction of power flow

I use “Three-Phase V-I Measurement” block to measure Vabc and Iabc, and then use “Power (3ph, Phasor)” block to calculate P and Q. Could someone please confirm that positive P or Q means that power flows from capital A B C letters on “Three-Phase V-I Measurement” block towards small a b c on the same block. Or is there a completely different logic?

There is a figure on “Power (3ph, Phasor)” block’s help page, but its meaning is not clear to me.

Answer 1

[Rhea Chandy]

Hi!

I understand that you want to know whether positive P and Q implies that power flows from the capital notation ABC letters on the block through the letters abc notation.

Indeed, yes, that is the case regarding the Three-Phase V-I Measurement block. An example,

power_PhasorPowerMeasurements  

shows the use of both the Power (3ph, Phasor) block and the three-Phase V-I Measurement block in simscape. This may help you gain an understand of the direction of power flow. The example is listed in the documentation for Power (3ph, Phasor) block.

[Miroslav Blagojevic]

Hi Rhea,

Thank you for your answer. I thought that should be the case, and indeed, in some places in my Simulink model that is how the block works. But with one particular subsystem, the block showed opposite of what I expected, and I was pretty sure the subsystem was fine. Thanks to your answer, I found an error in the subsystem, so all is good now. Thank you again. Still think the figure on the help page could be clearer.