Negative average power. What does it mean?

[James20]

Negative average power. What does it mean?

Hi. What it means negative values for average power?

MultisimOutputParametersVersion.PNG

In Multisim 14.2 I have negative average power values for P_Input, P_B1, P_B2. avg(P_Input)<0, avg(P_B1)<0, avg(P_B2)<0

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Please see attached circuit Multisim forum.ms14

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I am doing Transient analysis .

avg(P_Input) is input average power of V6 Voltage Source

avg(P_B1) is input average power of V3 Voltage Source

avg(P_B2) is input average power of V2 Voltage Source

 

[rjenkinsgb]

At a guess, all the series L-C sections are causing phase shifts and causing the instantaneous A * V power calculations to give confusing results.
A bad power factor, in other words; current and voltage significantly out of phase. (Why transformers etc. are rated in "VA" rather than Watts),

Power factor - Wikipedia

en.wikipedia.org

Also, using AC sources to represent batteries seems rather strange? There will be phase interactions with the input supply causing odd readings.

A battery will only take charge current above a certain voltage, regulated or limited by both it's internal resistance and the external source voltage and resistance.

I'd represent the batteries with either a 12V Zener and series resistor, or a DC supply with a low value parallel resistor to carry the "charge" current (lessening the load on its directly connected supply as charge current increases).

 

[Tony Stewart]

All dissipated power is +ve and generated power is -ve. Thus Net phasor sum of energy is zero over an integer number of cycles, as all power is accounted for including that stored in LC reactors as no energy is destroyed.