Calculating Complex Power: P+jQ

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Discussion Overview

The discussion centers around the concept of complex power in electrical engineering, specifically the relationship between real power (P), reactive power (Q), and their representation in phasor form. Participants explore the implications of different formulations of complex power and its interpretation as both a scalar and a phasor.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant questions whether complex power, represented as P+jQ, is a phasor representation of the terms P(cos(2wt)) and Q(cos(2wt)), and why the first term is seemingly ignored.
  • Another participant notes that complex power can be expressed as both a scalar (Veff)(Ieff) and a phasor (Vphasor)(Iphasor)/2, raising the question of how complex power can simultaneously be both forms.
  • A later reply references an external resource that may clarify the initial questions about complex power.
  • One participant reiterates the initial question about the relationship between electrical power as a dot product of voltage and current vectors, questioning the role of "jQ" and the terminology used in the context of complex power.

Areas of Agreement / Disagreement

Participants express uncertainty regarding the interpretation of complex power, with multiple competing views on its representation and the implications of its scalar and phasor forms. The discussion remains unresolved.

Contextual Notes

There are limitations in the assumptions made about the relationship between the terms in the power equations and the definitions of complex power. The discussion does not resolve these ambiguities.

chopficaro
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power=P+P(cos(2wt))+Q(cos(2wt))

but

complex power = P+jQ

am i to assume that complex power is a phasor representation of the last two terms? why does this formula ignore the first term?
 
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and aparently it is also equal to

complex power =(Veff)(Ieff)

which is a scalar, but its also equal to

complex power=(Vphasor)(Iphasor)/2

which is a phasor

how can complex power be both a phasor and a scaler?
 
Please give this a read and see if it answers your question. I think it's good.
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/powerac.html"
 
Last edited by a moderator:
it did! tyvm!
 
chopficaro said:
power=P+P(cos(2wt))+Q(cos(2wt))

but

complex power = P+jQ

am i to assume that complex power is a phasor representation of the last two terms? why does this formula ignore the first term?

Surely Electrical Power is the Dot Produce between the V and I vectors. A dot product is a scalar.
What could "jQ" be? I and V may not be in phase but what has that to do with "complex power"? Is there some problem with actual terminology here?
 

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