Dear José
Marcos,
I used the PV object you sent as IDF, and it
worked without a trouble!
Many thank ? >
But before you suggested that, and out of desperation,
I tried to change the number of cells input. Actually, I tried many PV inputs
from different catalogues, and they had one thing in common: number of cells=
60 or higher/ per module? so, when I reduced the number of cells too 50 (without
changing the rest of inputs)? it worked! Then, I looked on the web for another
catalogue and found a great one with 54 cells? and the simulation wwas a
success?
But why it worked?
When I looked for answers, I found this in the [Input-Output
Reference / Group -- Electric Load Center-Generator
Specifications / Field:
Number of Cells in Series / Page: 1624]: Kindly find attached
Even with that said, I didn't understand why I got
error from start as my inputs were (Cells#60 and 28.5V) reasonable double!... Anyway,
I guess there is a link between the number of cells and the error I had ((Photovoltaic
model failed to find maximum power point))?
I appreciate your help ? thank you for your time
and effort
----------------------------------------------------
Best
Regards,
Sarah Al
Jarallah
From: JOSE MARCOS CHAVES BARBOSA <zemarcoscb@xxxxxxxxxxxx>
To: "EnergyPlus_Support@xxxxxxxxxxxxxxx" <EnergyPlus_Support@xxxxxxxxxxxxxxx>; "sarahalghamdi@xxxxxxxxx" <sarahalghamdi@xxxxxxxxx>
Sent: Monday, February 18, 2013 8:06 AM
Subject: Re: [EnergyPlus_Support] Fatal Error: Photovoltaic (EquivalentOne-Diode) ..
Ok Sarah. Let's see.
Try to use the values of V_oc, V_mpp, I_sc and I_mpp from the table "PERFORMANCE UNDER STANDARD TEST CONDITIONS (STC)*" in your datasheet instead of the values from "PERFORMANCE AT 800 W/m², NOCT, AM 1.5". Also recalculate the temperature coefficients, because I think they were obtained relatively to the data of the table "PERFORMANCE UNDER STANDARD TEST CONDITIONS (STC)*". Someone disagree? I would like to know.
Be careful with the values and its respective test conditions. As you can see, in NOCT testing the value of insolation is 800 [W/m^2] and cell temperature is a result from the test, while in STC these conditions are 1000[W/m^2] and 298,15[K] (or 25[ºC]).
Here I have one alert, in I/O Reference we can see: "Field: Reference Temperature: This field is the ambient temperature (in Kelvin) at reference conditions. The value is usually 298K". What doesn't seems right, once the model needs a cell temperature reference, additionaly, the unit is not [K] in the IDFEditor, it's [ºC].
Try to use the values of V_oc, V_mpp, I_sc and I_mpp from the table "PERFORMANCE UNDER STANDARD TEST CONDITIONS (STC)*" in your datasheet instead of the values from "PERFORMANCE AT 800 W/m², NOCT, AM 1.5". Also recalculate the temperature coefficients, because I think they were obtained relatively to the data of the table "PERFORMANCE UNDER STANDARD TEST CONDITIONS (STC)*". Someone disagree? I would like to know.
Be careful with the values and its respective test conditions. As you can see, in NOCT testing the value of insolation is 800 [W/m^2] and cell temperature is a result from the test, while in STC these conditions are 1000[W/m^2] and 298,15[K] (or 25[ºC]).
Here I have one alert, in I/O Reference we can see: "Field: Reference Temperature: This field is the ambient temperature (in Kelvin) at reference conditions. The value is usually 298K". What doesn't seems right, once the model needs a cell temperature reference, additionaly, the unit is not [K] in the IDFEditor, it's [ºC].
Here the simulation runs with the model like in the IDF file attached.
OBS:
>Sorry for my English.
OBS:
>Sorry for my English.
José Marcos
CEFET-MG / Brasil
________________________________
De: Sarah Al Jarallah <sarahalghamdi@xxxxxxxxx>
Para: "EnergyPlus_Support@xxxxxxxxxxxxxxx" <EnergyPlus_Support@xxxxxxxxxxxxxxx>
Enviadas: Domingo, 17 de Fevereiro de 2013 5:04
Assunto: Re: [EnergyPlus_Support] Fatal Error: Photovoltaic (EquivalentOne-Diode) ..
Dear José Marcos,
Thank
you ?
That was
the first mistake I did. But with the help of Mr. Xiang Jing ZHANG, I was able
to convert the temperature coefficients from [%/k] to [A/K and V/K] â?¦ Unfortunately,
even with that done I still got the same error but with different numbers:
** Severe ** EquivalentOneDiode Photovoltaic model
failed to find maximum power point
** ~~~ ** Numerical solver failed trying to take
exponential of too large a number
** ~~~ **
Check input data in PhotovoltaicPerformance:EquivalentOne-Diode
** ~~~ ** VV (voltage) = -7519.13932
** ~~~ ** II (current) = 0.00000
** Fatal ** FUN: EnergyPlus terminates because of
numerical problem in EquivalentOne-Diode PV model
I couldnâ??t
figure out what I did wrong?¦ Is it because I entered default values in some of
the table boxes together with values from catalogue?? Kindly find attached ?
Best
Regards,
Sarah Al
Jarallah
________________________________
From: JOSE MARCOS CHAVES BARBOSA <zemarcoscb@xxxxxxxxxxxx>
To: "EnergyPlus_Support@xxxxxxxxxxxxxxx" <EnergyPlus_Support@xxxxxxxxxxxxxxx>
Sent: Sunday, February 17, 2013 9:46 AM
Subject: Re: [EnergyPlus_Support] Fatal Error: Photovoltaic (EquivalentOne-Diode) ..
Hello.
Perhaps you should look to the temperature coefficients. Make sure that the units are consistent comparing the datasheet data with the EP data.
Here, with the corrected values it could run a simulation (values from the datasheet which you sent converted into [A/K] and [V/K]), while with the values directly from the datasheet (both in [%/K]) I got this error message:
** Severe ** EquivalentOneDiode Photovoltaic model failed to find maximum power point
** ~~~ ** Numerical solver failed trying to take exponential of too large a number
** ~~~ ** Check input data in PhotovoltaicPerformance:EquivalentOne-Diode
** ~~~ ** VV (voltage) = 24.62826
** ~~~ ** II (current) = -3084.79299
** Fatal ** FUN: EnergyPlus terminates because of numerical problem in EquivalentOne-Diode PV model
Obs:
>Probably (almost sure) my IDF file is diferent than yours.
>Sorry for my English.
José Marcos
CEFET-MG / Brasil
________________________________
De: Sarah Al Jarallah <sarahalghamdi@xxxxxxxxx>
Para: "energyplus_support@xxxxxxxxxxxxxxx" <energyplus_support@xxxxxxxxxxxxxxx>
Enviadas: Sábado, 16 de Fevereiro de 2013 16:52
Assunto: [EnergyPlus_Support] Fatal Error: Photovoltaic (EquivalentOne-Diode) ..
Dear all,
At the mean time, Iâ??m modeling a single-family house with PV
system by using the (PhotovoltaicPerformance:EquivalentOne-Diode) type .. At first, I tried the PV characteristics given
in example file "GeneratorwithPV" where the simulation went smoothly
and I got results. But when I used PV characteristics(attached)from a catalogue I got fatal error:
**
Severe ** EquivalentOneDiode
Photovoltaic model failed to find maximum power point
**
~~~ ** Numerical solver failed
trying to take exponential of too large a number
**
~~~ ** Check input data in
PhotovoltaicPerformance:EquivalentOne-Diode
**
~~~ ** VV (voltage) =
-7519.13932
**
~~~ ** II (current) = 0.00000
**
Fatal ** FUN: EnergyPlus
terminates because of numerical problem in EquivalentOne-Diode PV model
I would appreciate
your help..
Thank you ..
-----------------------------------------------
Best
Regards,
Sarah Al
Jarallah