How to extract the electric parameters Rs, Rsh of my solar cell

[wachhad]

Dear sir, hello (aslam alaikom)
I am a beginner in solar cell simulation, and I am a beginner in MATLAB programming,
First I have a problem to extract the electric parameters Rs, Rsh of my solar cell,
After the simulation of solar cell I have these results: Isc , Voc , Pmax , Vmax , Imax , FF

I=[70.35 70.11 69.85 69.59 69.31 69.03 68.72 68.40 68.07 67.72 67.35 66.97 66.56 66.13 65.68 65.20 64.70 64.17 63.61 63.01 62.38 61.71 61.00 60.24 59.43 58.57 57.64 56.64 55.57 54.40 53.13 51.75 50.23 48.54 46.65 44.51 42.02 39.08 35.48 30.90 24.87 16.66 5.26 0.00] ;

V=[0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0.22 0.24 0.26 0.28 0.3 0.32 0.34 0.36 0.38 0.4 0.42 0.44 0.46 0.48 0.5 0.52 0.54 0.56 0.58 0.6 0.62 0.64 0.66 0.68 0.7 0.72 0.74 0.76 0.78 0.8 0.82 0.84 0.86 0.8673] ;

Rs-1 = [ dI ∕ dV] I = 0
Rp-1 = [ dI ∕ dV] V = 0

So please help me to extract the series Rs and shunt Rsh resistances of this solar cell,
I am in need to the MATLAB code that extract out Rsh and Rs from the input I V characteristics,

I have the honor to benefit from your experience,
So please help me as soon as possible,
With my best wishes,
Thank you in advance.

 

[srizbf]

can you explain the equations?:
....
Rs-1 = [ dI ∕ dV] I = 0
Rp-1 = [ dI ∕ dV] V = 0
.......

 

[erikl]

Rs-1 = [ dI ∕ dV] I = 0
Rp-1 = [ dI ∕ dV] V = 0

Resistances [R = V/I] are measured as [voltage/current], hence extracted from a non-linear I vs. V characteristic it should be [ dV ∕ dI ].

Rs measured @ I = 0
Rp measured @ (extrapolated) V = 0

 

[wachhad]

can you explain the equations?:
....
Rs-1 = [ dI ∕ dV] I = 0
Rp-1 = [ dI ∕ dV] V = 0
.......

Thank you Sir,
Please read the attached file "Solar cell output parameters" to get the explain,
note: My results are simulation results not experimental results,
View attachment Solar cell output parameters.doc
View attachment Solar cell output parameters.rar
View attachment Solar cell output parameters.pdf

 

[srizbf]

Thank you Sir,
Please read the attached file "Solar cell output parameters" to get the explain,
note: My results are simulation results not experimental results,
View attachment 72577
View attachment 72578
View attachment 72579

all your attached files does not contain the reqd documents.
it seems that there is a virus/hidden codes in all files.
try to upload proper ones.

 

[wachhad]

all your attached files does not contain the reqd documents.
it seems that there is a virus/hidden codes in all files.
try to upload proper ones.

Thank you Sir,
I try upload again but there is the same problem,
Please contact me by my Email: benlekhdimahmed@hotmail.fr to attached to you my file,
View attachment Solar cell output parameters.pdf

 

[erikl]

I ... need .. the MATLAB code that extract out Rsh and Rs from the input I V characteristics

You wouldn't necessarily need MATLAB. You could do it with Excel:

 

[wachhad]

You wouldn't necessarily need MATLAB. You could do it with Excel:

Thank you, but the link of your attached file "solar_cell_characteristic.pdf" not work, there is a problem to download it,
So Please send your attached file "solar_cell_characteristic.pdf" to my Email : benlekhdimahmed@hotmail.fr

 

[erikl]

... the link of your attached file "solar_cell_characteristic.pdf" not work, there is a problem to download it

It works with a simple click, I just tried it. Try once more!

 

[wachhad]

It works with a simple click, I just tried it. Try once more!

thank you erikl,
First Please attached your excel file,
second what is your calculated R = δV/δI it is Rs or Rsh,
Thirdly the Rs must be one value and Rsh must be one value,
So please download my last attached file "Solar cell output parameters" to understand what is Rs and Rsh and understand the problem,
Thank very much again

 

[srizbf]

thank you erikl,
First Please attached your excel file,
second what is your calculated R = δV/δI it is Rs or Rsh,
Thirdly the Rs must be one value and Rsh must be one value,
So please download my last attached file "Solar cell output parameters" to understand what is Rs and Rsh and understand the problem,
Thank very much again

Rs=1.3878 ohms and Rp=83.33 ohms.
does it tally with your work?

 

[wachhad]

Rs=1.3878 ohms and Rp=83.33 ohms.
does it tally with your work?

I am sorry srizbf,
thank you very much for you contribution,
First how you calculate the Rs and Rsh, how you find: Rs=1.3878 ohms and Rp=83.33 ohms, Please attached file to explain the method,
Second Please attached your code Program file which calculate the last values, because I have many simulation results: I=f(V)
Thank you again,
with my best wishes, I am waiting for your response

 

[erikl]

First how you calculate the Rs and Rsh, how you find: Rs=1.3878 ohms and Rp=83.33 ohms, Please attached file to explain the method

Your values are rather close to my results. So you already know how to calculate these differential resistance values.

Second Please attached your code excel file which calculate the last values

You can easily create such an Excel file yourself. Forum members won't save you your homework :twisted:
BTW: Just now I don't have an Excel file for this calc. I used another tool ;-)

 

[wachhad]

Your values are rather close to my results. So you already know how to calculate these differential resistance values.


You can easily create such an Excel file yourself. Forum members won't save you your homework :twisted:
BTW: Just now I don't have an Excel file for this calc. I used another tool ;-)

thank you very much erikl,
yes I think I can easily to create such an Excel file to calculate R = δV/δI values like what you do in solar_cell_characteristic.pdf,
But I have not a method to calculate Rs and Rsh from R = δV/δI excel column,
So what is your tool? can you help me,
Thank you again,
with my best wishes,

 

[erikl]

yes I think I can easily to create such an Excel file to calculate R = δV/δI values like what you do in solar_cell_characteristic.pdf,
But I have not a method to calculate Rs and Rsh from R = δV/δI excel column,
So what is your tool? can you help me

To calculate R = δV/δI , I used
R = 1000*(V_n+1 - V_n-1) / (I_n-1 - I_n+1)
V in [V] ; I in [mA]

With this method, I got Rs=1.39Ω and Rp=95.2Ω -- after extrapolating I(0 V) and I(-0.02V), by continuing δV/δI and δ²V/δI² from your last given point (0.02V) down to -0.02V : **broken link removed**

Note: The blue-grey values are extrapolated values. The yellowish background values show the max. power point.

Note: Corrected items in red. Corrected attachment.

 

[wachhad]

To calculate R = δV/δI , I used
R = 1000*(V_n+1 - V_n-1) / (I_n-1 - I_n+1)
V in [V] ; I in [mA]

With this method, I got Rs=1.39Ω and Rp=95.2Ω -- after extrapolating I(0 V) and I(-0.02V), by continuing δV/δI and δ²V/δI² from your last given point (0.02V) down to -0.02V : **broken link removed**

Note: The blue-grey values are extrapolated values. The yellowish background values show the max. power point.

Note: Corrected items in red. Corrected attachment.

thank you very much erikl,
In the first time you got Rs=1.39Ω and Rp=57.6Ω after that you got Rs=1.39Ω and Rp=95.2Ω Why?,
So What is the percentage error in your method,
Because I am a beginner in solar cell simulation, and I am a beginner in programming language , I can't evaluate your method work,
For me I have algorithm about some methods to calculated Rs and Rsh of solar cell like Newton-Raphson method
but I can't create the code program by MATLAB language for example, are you Know like this method? are you can create a code program of my algorithm?
Thank you again,
with my best wishes,

 

[erikl]

In the first time you got Rs=1.3878 ohms and Rp=83.33 ohms

No. This came from srizbf's contribution (#11).

after that you got Rs=1.39Ω and Rp=57.6Ω after that you got Rs=1.39Ω and Rp=95.2Ω Why?

The first Rp=57.6Ω value was an error in my calculation. I think the latter one should be right.

... you can create a code program of my algorithm?

No. I already told you how I did it (#15).

 

[wachhad]

thank you very much erikl,
I hope to benefit from your experience in the future:roll:
with my best wishes,

---------- Post added at 18:41 ---------- Previous post was at 18:37 ----------

I am sorry srizbf
thank you very much for your contribution,
First how you calculate the Rs and Rsh, how you find: Rs=1.3878 ohms and Rp=83.33 ohms, Please attached file to explain the method,
Second Please attached your code Program file which calculate the last values, because I have many simulation results: I=f(V)
with my best wishes, I am waiting for your response

 

[srizbf]

i have just used the claculator for computing Rs and Rp.
that is why , i have posted it and wanted you to check it with whatever values you have.

 

[wachhad]

Dear erikl, hello (aslam alaikom)
I am in need to your help again,
I have a new results simulation IV solar cell characterizations :

I=[25.8186 25.6861 25.5488 25.4064 25.2586 25.1053 24.946 24.7805 24.6085 24.4295 24.2431 24.0489 23.8464 23.6349 23.414 23.1828 22.9406 22.6865 22.4193 22.1379 21.8409 21.5266 21.1929 20.8374 20.4572 20.0484 19.6065 19.1254 18.5973 18.0118 17.355 16.6076 15.7437 14.7275 13.5117 12.0354 10.2252 8.00124 5.28803 2.02924 1.06596e-011] ;
V=[0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0.22 0.24 0.26 0.28 0.3 0.32 0.34 0.36 0.38 0.4 0.42 0.44 0.46 0.48 0.5 0.52 0.54 0.56 0.58 0.6 0.62 0.64 0.66 0.68 0.7 0.72 0.74 0.76 0.78 0.79097] ;

So please help me to extract the series Rs and shunt Rsh resistances of each IV characterization :

I have the honor to benefit from your experience again,
So please help me as soon as possible,
With my best wishes,
Thank you in advance.