How to eliminate phase shift between signals?

[jak9]

hello friends,
I have a voltage and current input signal in simulink which has a small phase shift between the two signals. Is their a way so that i can eliminate this phase difference to zero?
thanks

 

[jonlg_uk]

Can you not just add some capacitive or inductive compensation to the shifted signal...?

 

[sophiecentaur]

Perhaps a bit of basic electrical theory might be useful before leaping into a simulation? In 'the old days' no one would have expected to understand things if they relied on a soldering iron and a box of components (suck it and see). The only difference between that and a simulation is that a simulation can be modified much quicker.
It could be analogous to monkeys and typewriters, I think.

 

[jak9]

thanks but can't get your point

 

[likephysics]

Where are the inputs coming from? Why is there a phase shift. Do you know?
I think sophiecentaur is trying to tell you that you should know some basic electronics before you jump into simulation.

 

[jak9]

thanks...these inputs is an array defined in a workspace...i know the phase shift is because of capacitor which makes the current to lead voltage but i have nothing to do with this because i have to just plot this values in simulink and want to have a zero phase difference so that i can use further for my analysis

 

[sophiecentaur]

thanks...these inputs is an array defined in a workspace...i know the phase shift is because of capacitor which makes the current to lead voltage but i have nothing to do with this because i have to just plot this values in simulink and want to have a zero phase difference so that i can use further for my analysis

You have just confirmed my original point. It's a simulation. It is there to represent some real situation, involving electronic components, voltages and currents, isn't it?
To answer your question in the way you are asking it, all I can say is that the values in the array make the phase what it is. If you consider what your array actually represents then you may be able to relate things to the action of the components involved. It is likely that, if all the values in that array are real then there should be no phase shift on the input terminal. If that means noting to you then you need to do some circuit theory. Isn't that what your course is about?

 

[jak9]

yes you are right...its because of the values in the array i tried with filters but they too cause phase and magnitude shift so let see what happens...anyways thanks for all your help and advices

 

[sophiecentaur]

What actual components do the array values represent? That's the important thing, surely.

 

[jak9]

well the array is voltage values and the other is current values
each array has one column of timevalues and another column of voltage/current values
for e.g: - V(100*2)

 

[berkeman]

well the array is voltage values and the other is current values
each array has one column of timevalues and another column of voltage/current values
for e.g: - V(100*2)

That didn't answer centaur's question:

What actual components do the array values represent? That's the important thing, surely.

Are the (V,I) pairs representative of values from a circuit's operation? What is the circuit? Why do you want to change their relationship in phase? That relationship would normally be important in a simulation environment, no?

 

[sophiecentaur]

I think I see where he's coming from. There is an input signal from it-matters-not-where and because it V and I are not in phase it is from a source with complex impedance. The OP uses the term "phase shift" when it just means a phase difference between V and I.
As an exercise, it has just generated some confusion for him ( and the rest of us).
He can:
1. Change the numbers in the input array: that will eliminate the phase difference.
2. Introduce an RC or RL combination to eliminate the phase difference (at one particular frequency). That is, actually, a straightforward 'exercise for the student' - just the other way round from what we normally come across and just calls for some rearranging of a well known formula.

 

[jak9]

thanks...these V & I are the reading taken from the battery terminal of a car

 

[sophiecentaur]

OMG, an added complication. Are the variations due to the AC component from the alternator (relatively fast, added to the 13V charging voltage) or due to some quirk of the battery under load (very slow)?
Just when we though we had it all sewn up.

 

[jak9]

its because of alternator as the output from the rectifier of the alternator is not a pure dc

 

[sophiecentaur]

and the measured V I phase difference is because of the source reactance of the alternator? Fair enough.
In your original question you wanted to eliminate the phase difference - I already posted how to do that. One solution would involve simulating an appropriate (power factor) compensating network between your source and the following simulated circuit.

Is your course about electrical theory or programming? If it's about electrical theory then I still say that you should do some basics before you enter into simulations, which can be fooled into letting you do almost anything. (I have never died whilst landing on a Flight Simulator, for instance).