Help olving solar PV implicit eq

[dipeshchauhan]

Hello all i m new to Mathcad ...i want to plot the curve between I and V. But the equation is implicit with respect to I. It's given below

I have numerical values of Il,Voc,Rs,Rp,ekt. V will take values from 0 to Voc.

Please help me how to do this

[MikeArmstrong]

Can you post a worksheet? Mathcad 11 preferably.

Mike

[dipeshchauhan]

Here I have included the mathcad 11 file .

[AlanStevens]

The attached should help.

Alan

Edited: file updated with required voltage range

[dipeshchauhan]

Alan , i don't think this works for me .

I have changed a little in it and found the graph is not matching with the standard results. I am attaching the standard V-I curve for the solar panel also for V=0, I=Isc and for I=0 , V=Voc.

I have also attached the Mathcad file i have modefied .

[AlanStevens]

Look at the revised file I posted. My original one didn't have the voltage range you required. The new one does and the graph looks like the one you've posted.

Alan

[AlanStevens]

Actually, on closer inspection it's not identical. Are you confident the constants you supplied are those used to generate the graph you showed? Or, more likely, have I implemented the wrong constants?

Alan

[dipeshchauhan]

The constants are correct as per my knowledge.But I=0 happening at around 19.4V. May be this given , find block is not good enough to find out the solution accurately . Do u know any other method of this kind of implicit function.

[AlanStevens]

dipesh chauhan wrote:

The constants are correct as per my knowledge.But I=0 happening at around 19.4V. May be this given , find block is not good enough to find out the solution accurately . Do u know any other method of this kind of implicit function.

It's not the solve block that's the problem. If you substitute V=Voc and I = 0 into the right-hand side of your implicit function you get 2.08 amps, not zero amps. Hence your function isn't consistent with I=0 at V=Voc.

Alan

[dipeshchauhan]

Thanks a lot Alan ,

I m not sure what is wrong now. Actually with the I-V curve one should have V=0 at I=Isc that's I=3.29A. This is ok .

But when one look for point where I=0 , V should be open circuit , that is V=Voc that's 18.2V

[AlanStevens]

I've noticed one error in my original worksheet - the brackets in the function were in the wrong place! However, correcting this hasn't improved the situation!! See attached.

Alan