Electrical PE Exam - The Conjugate (S=VI*) [part 2]

[@kerlyn]

@MsAppledance - he said in part 1 that the (complex) conjugate in not merely flipping the I vector about the V vector. The conjugate IS the inverse of the sign of the complex component, effectively flipping the I vector about the X axis. The only time the two are equivalent is when theta of V is zero (and P = VI is valid).

[@withinyou42]

Is the leading and lagging representation correct here? Shouldn't leading side have current at a greater angle than voltage? and shouldn't lagging side have current at a lesser angle than voltage?

[@jakeowsley6552]

Phi for "we want this" should actually be phi(v) - phi(i), thus the sign convention for leading (+angle) or lagging (-angle), relative to voltage vector. This would be important to get the sign of the reactive power correct.

[@wagsman9999]

Clearly explained - thanks

[@neilAneerGAmAI]

This video is excellent.

[@RashmilDahanayake]

The definition of leading and lagging definition seems to be incorrect. In standard practice, the term leading and lagging in expressed in terms of the current. For example Leading PF means current leads voltage ; and Lagging PF means current laggs voltage

[@edwardmccann2123]

Conjugate shown in list as theta I plus theta v is not correct. Conjugate should be theta v minus theta I Correct?

[@europestudygoal5923]

thanks for easy and understandable example.

[@2002yeunglau]

love that explanation thats really help to inspire me thanks!!

[@MsAppledance]

I don't understand your explanation. Before, you said that the conjugate is NOT merely flipping the sign for the current phasor... but here, we see that.. since it is theta v + theta i, then it IS just the same as effectively flipping the current phasor across the x axis. I'm also confused that you use the phi* for the S=VI, but the regular phi for S=VI*. Is this just the convention? How do you explain that?

[@anonymousrenegade4113]

difference between the appended angles matter the most to meet the reality or physical order.. forget about positive, negative or flipping the phasors..

[@LouDFrog15]

Firstly why polar notation is used instead of time varying signal. What happens to frequency?

[@Mephibosheth94]

Thanks a lot... I was searching for this. Now I clearly understand about power calculation with conjugate.

[@abdulkadirarslan6959]

Thank you very much sir, it was very useful for me.

[@gudellithrishool2249]

can we take v conjugate y don't we?

[@anonymousrenegade4113]

most in cases we consider voltage as constant.. by taking conjugate of voltage won't make that much effect for absolute calculation..

[@mark182sk8]

great explanation! thanks :D

[@mohannadmaklad256]

That was great. but I think you forget to put "j" before the second term after changing from polar form to the rectangular form.

[@nickyyuen9426]

thank you

[@henrymiller5709]

superclear，i love it

[@burry218]

Thank you!!!

[@muhammadtanvir5298]

Thank you.

[@riclyndonpasgala1039]

tnx man

[@maniys]

oh this is awesome,. thanks :)