I can't believe I've been going through my power systems analysis book looking at this I*, V*, and Z* without the book ever explaining what they were or how to gain an intuition for when they should be used. Thank you for explaining this.
Interpretation of current as reference, is same as saying I* is just I itself, thats why it becomes V × I* = V × I. In general, for any case the complex power is V × I*
if anyone is confused on how he did the expansion 5:10, its a polar (power angle) to rectangular (to cos and sin terms) expansion. In rectangular form you use the magnitude V and not the Vector V. And then he just multiplied those terms with the magnitude of I to get the rectangular expansion of apparent power S.
Sir if we take current as reference phasor even then complex power S will be equal to phasor voltage multipled by conjugate of phasor current. That means, S = phasor V × conjugate of phasor current I is a general formula for the calculation complex power. That means we do not need to remember any other rules for measuring complex power.
Most of all equiments connected in parallel fasion which draw different quantity of current w r t voltage remains same, hence voltage is taken as reference but due to this we sacrifing standerd conventions sign for inductive and capacitive load, to correct it we needs little efort of taking complex conjugate of current.
I learned polar and rectangular notation; polar form for multiplication and division of complex numbers and rectangular form for addition and subtraction. I've never heard of "conjugate".
I am little bit not agreeing with this logic no doubt correct . But in order to ignore the logic of convention match we can take it as the +ev power factor angle (C.C.W) should be there in cosine power and sine power always. Like to make Alpha + Beta case we can simply say as invert the angle of current from minus beta to plus beta so that we get a positive power angle (counter clockwise) between voltage and current. Same logic can be justified when we take the voltage as reference , i.e to make the power factor angle as +ev (C.C.W) we have to invert the current angle from minus Phi to +ve phi so that the power factor angle becomes Phi + 0 as +ve phi. Please comment on my proposed logic of mathematics to be incorporated in this regard.
@@ashishkumartripathi1687 kWh meter works on deflection principle.. apart from that it not only tracks the data but it does process & evaluate the net consumption as well..
why'd you initially write the entire expansion of VI vectors as -, you saying the power angle is negative and then later say its positive. why'd you even initially say its engative?
Current(I) conjugate gives correct sign for reactive power consumption by the inductive and capacitive load where as voltage conujgate can't give the proper sign for reactive power consumption by the inductive and capacitive load... so use S=vi* instead of v*i
Nonsense! If current is taken reference, i and i* will be same. That why there won’t be any difference if you take i or i*. Simply making things complicated. (V.i* is valid even if i was taken reference)
@@ThePiSquareAcademy sir, i didn't mean to be rude.. i'm sorry. Videos on your channel are interesting and really helpful for interviews. But this one, i was expecting some interesting explanation. :)
![Electrical PE Exam - The Conjugate (S=VI*) [part 1]](http://i.ytimg.com/vi/Xo0-3LtVea0/mqdefault.jpg)
I can't believe I've been going through my power systems analysis book looking at this I*, V*, and Z* without the book ever explaining what they were or how to gain an intuition for when they should be used. Thank you for explaining this.
Interpretation of current as reference, is same as saying I* is just I itself, thats why it becomes V × I* = V × I. In general, for any case the complex power is V × I*
Thotakura NSC Sekhar gives a clear and simple explanation for the complex power conjugate formula. Well worth the time taken to listen.
if anyone is confused on how he did the expansion 5:10, its a polar (power angle) to rectangular (to cos and sin terms) expansion. In rectangular form you use the magnitude V and not the Vector V. And then he just multiplied those terms with the magnitude of I to get the rectangular expansion of apparent power S.
Simply outstanding explanation.
Correct
Sir if we take current as reference phasor even then complex power S will be equal to phasor voltage multipled by conjugate of phasor current. That means, S = phasor V × conjugate of phasor current I is a general formula for the calculation complex power.
That means we do not need to remember any other rules for measuring complex power.
Most of all equiments connected in parallel fasion which draw different quantity of current w r t voltage remains same, hence voltage is taken as reference but due to this we sacrifing standerd conventions sign for inductive and capacitive load, to correct it we needs little efort of taking complex conjugate of current.
this cleared up a lot for me, thank you!!!
Very good explaining
thanks for valuable lecture
thank you Dhanush...
You are most welcome Shah Rukh 😊
I learned polar and rectangular notation; polar form for multiplication and division of complex numbers and rectangular form for addition and subtraction. I've never heard of "conjugate".
excelent explanation
thank you sir great explanation
Very good. Thanks 🙏🙏🙏🙏🙏🙏
if current is taken as reference , i and i (conjugate) both are same.
mind = blown!!
Thank you so much!
NICE EXPLANATION SIR..MOST OF UR VIDEOS ARE AMAZING BY ITS FANTABULOUS CONTENT..
Thank you sir am understand your point.
Super sir
Thanks a lot of sirrrrr jiii
Thanks a lot sir...
Wow... Need some more explanation... Thank you..
Really nice explanation...😘
Thanku sir
Amazing
I am little bit not agreeing with this logic no doubt correct .
But in order to ignore the logic of convention match we can take it as the +ev power factor angle (C.C.W) should be there in cosine power and sine power always. Like to make Alpha + Beta case we can simply say as invert the angle of current from minus beta to plus beta so that we get a positive power angle (counter clockwise) between voltage and current.
Same logic can be justified when we take the voltage as reference , i.e to make the power factor angle as +ev (C.C.W) we have to invert the current angle from minus Phi to +ve phi so that the power factor angle becomes Phi + 0 as +ve phi.
Please comment on my proposed logic of mathematics to be incorporated in this regard.
sir what if s=v*i means?
becoz its also have been used in some concepts . #PiSquare Academy
Tq so much sir
U r great sir
Magnitude of VI and VI* is same. Phase only differs. Othe than mathematical convenience, any advantage we get by using conjugate current?
The kwh meter can be classified as a/an instrument
a)deflecting b)digital
c)recording d) indicating
sekhar sir, ish question ka answer kya hoga ?
interesting question, answer is a deflecting .
@@ThePiSquareAcademy sir recording kyo nahi hoga
@@ashishkumartripathi1687 kWh meter works on deflection principle.. apart from that it not only tracks the data but it does process & evaluate the net consumption as well..
Sir can u explain why capacitor bank is stopped while dg set is running... With formula
why'd you initially write the entire expansion of VI vectors as -, you saying the power angle is negative and then later say its positive. why'd you even initially say its engative?
sir, make a video on explaination of faradys cage
thanks Sir my question is How we can take current as reference when it is leading
If we change sign convention we will get it correct?
Current(I) conjugate gives correct sign for reactive power consumption by the inductive and capacitive load where as voltage conujgate can't give the proper sign for reactive power consumption by the inductive and capacitive load... so use S=vi* instead of v*i
Best thing
Why circle diagram is drawn for 3 phase induction motor , why not drawn for 1 phase induction motor and transformer.
Nonsense! If current is taken reference, i and i* will be same. That why there won’t be any difference if you take i or i*. Simply making things complicated. (V.i* is valid even if i was taken reference)
Yes. You are correct, its nonsense :)
@@ThePiSquareAcademy sir, i didn't mean to be rude.. i'm sorry. Videos on your channel are interesting and really helpful for interviews. But this one, i was expecting some interesting explanation. :)
Why Only 12V Battery Why Can't Above 12V Like 100V Battery,50V Battery etc... Make a video on Above
We can make it, but it make the cost very high& weight of the battery is also high....
I think ur a Telugu
Thotakura
Even when we use current(I) as reference, S=VI* is correct complex power.Because current (I )will be at angle zero and hence I*=I.
V=V
Is it possible s=v*I
It would have been better to explain it with a numerical problem.
Can we store Lightning Surge Energy make a video
☺️
You look like arvind arora
Sir Hindi me video banaiye
In NPTEL lecture as well they provided the same description because of the convention...
U need to improve handwriting for clear idea
Sure. Thanks for the feedback