> Johann Klammer says...
>
> > Put this in your standard.dio:
>
> Thanks very much.
>
> Can you tell me what all of that produces - in terms of the
> open circuit voltage and the short circuit current of a
> panel? Sorry to be so dense, but I have no experience with
> simulation at all. So does all of this create a new
> "device" that I can place on the schematic?
>
It's all guesses. bad ones.
I tried to calculate an N. but it turned ot wrong.
so it's trial and error basically.
(the lines starting with * are all comments)
Reply by Peabody●May 26, 20212021-05-26
Johann Klammer says...
> Put this in your standard.dio:
Thanks very much.
Can you tell me what all of that produces - in terms of the
open circuit voltage and the short circuit current of a
panel? Sorry to be so dense, but I have no experience with
simulation at all. So does all of this create a new
"device" that I can place on the schematic?
Reply by Klaus Vestergaard Kragelund●May 26, 20212021-05-26
On 26/05/2021 02.36, John Larkin wrote:
> On Tue, 25 May 2021 19:14:37 -0500, Peabody
> <waybackNO584SPAM44@yahoo.com> wrote:
>
>> I'm working on a TP4056-based 1S LIPO solar charger which includes a load
>> sharing (aka power path) function. But I don't have a panel to test with.
>> So I'd like to simulate the circuit in LT-Spice.
>>
>> But I've never used spice, LT or otherwise, so I was hoping to find an
>> example of a solar panel equivalent circuit that I could import, then add
>> the rest of the circuit, which is pretty simple.
>>
>> Can someone suggest where I would find such a file? It would be something
>> like a 5V panel, 200mA.
>>
>
> Wild guess to open discussion: a string of silicon power diodes with a
> parallel current source that represents illumination.
>
> LT Spice is great. It shouldn't take long to enter and run a circuit;
> ask here if it doesn't work. There are no doubt a lot of tutorials on
> youtube.
>
Yes, back when I was doing a MPPT function in a Space design, we just
used the diode string for simulation and test
Just remember to add a lot of capacitance, since that can be huge on
solar arrays
Cheers
Klaus
Reply by Johann Klammer●May 26, 20212021-05-26
Apologies,
A phony carriage return slipped in...
More correct:
*I_DD=Isc-Voc/Ri=8.563-0.622/1.156=8.024
*I_s=300n(guess)
*U_T=26mV
*U_D=0.622
*n*U_T*ln(I_DD/IS)=U_D
*n=U_D/(U_T*ln(I_DD/IS))=1.398
*duh.. have2guess for a better fit
*I_s=3n
.model PVCELL D(Is=3n N=1.1)
Reply by Johann Klammer●May 26, 20212021-05-26
On 05/26/2021 02:14 AM, Peabody wrote:
> I'm working on a TP4056-based 1S LIPO solar charger which includes a load
> sharing (aka power path) function. But I don't have a panel to test with.
> So I'd like to simulate the circuit in LT-Spice.
>
> But I've never used spice, LT or otherwise, so I was hoping to find an
> example of a solar panel equivalent circuit that I could import, then add
> the rest of the circuit, which is pretty simple.
>
> Can someone suggest where I would find such a file? It would be something
> like a 5V panel, 200mA.
>
>
Put this in your standard.dio:
*I_DD=Isc-Voc/Ri=8.563-0.622/1.156=8.024
*I_s=300n(guess)
*U_T=26mV
*U_D=0.622
*n*U_T*ln(I_DD/IS)=U_D
*n=U_D/(U_T*ln(I_DD/IS))=1.398
*duh.. have2guess for a better fit
*I_s=3n
.model PVCELL D(Is=3n N=1.1)^M
This in an .asc:
Version 4
SHEET 1 988 812
WIRE -288 192 -288 176
WIRE -288 704 -352 704
WIRE -288 768 -352 768
WIRE -192 176 -288 176
WIRE -192 176 -192 64
WIRE 64 64 -192 64
FLAG -192 256 0
FLAG -288 768 0
FLAG 64 144 0
SYMBOL current -192 256 R180
WINDOW 0 24 88 Left 0
WINDOW 3 24 0 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName I1
SYMATTR Value 8.563
SYMBOL diode -304 192 R0
SYMATTR InstName D1
SYMATTR Value PVCELL
SYMBOL diode -304 256 R0
SYMATTR InstName D2
SYMATTR Value PVCELL
SYMBOL diode -304 320 R0
SYMATTR InstName D3
SYMATTR Value PVCELL
SYMBOL diode -304 384 R0
SYMATTR InstName D4
SYMATTR Value PVCELL
SYMBOL diode -304 448 R0
SYMATTR InstName D5
SYMATTR Value PVCELL
SYMBOL diode -304 512 R0
SYMATTR InstName D6
SYMATTR Value PVCELL
SYMBOL diode -304 576 R0
SYMATTR InstName D7
SYMATTR Value PVCELL
SYMBOL diode -304 640 R0
SYMATTR InstName D8
SYMATTR Value PVCELL
SYMBOL diode -368 704 R0
SYMATTR InstName D9
SYMATTR Value PVCELL
SYMBOL current 64 64 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName I2
SYMATTR Value PWL(0 0 1 8.563)
TEXT -370 796 Left 0 !.tran 0 1 0 0.001
Reply by legg●May 26, 20212021-05-26
On Tue, 25 May 2021 19:14:37 -0500, Peabody
<waybackNO584SPAM44@yahoo.com> wrote:
>I'm working on a TP4056-based 1S LIPO solar charger which includes a load
>sharing (aka power path) function. But I don't have a panel to test with.
>So I'd like to simulate the circuit in LT-Spice.
>
>But I've never used spice, LT or otherwise, so I was hoping to find an
>example of a solar panel equivalent circuit that I could import, then add
>the rest of the circuit, which is pretty simple.
>
>Can someone suggest where I would find such a file? It would be something
>like a 5V panel, 200mA.
>
Get a panel. You may have to settle for 12V, based on availability
from current consumer cast-offs.
RL
Reply by John Larkin●May 25, 20212021-05-25
On Tue, 25 May 2021 19:14:37 -0500, Peabody
<waybackNO584SPAM44@yahoo.com> wrote:
>I'm working on a TP4056-based 1S LIPO solar charger which includes a load
>sharing (aka power path) function. But I don't have a panel to test with.
>So I'd like to simulate the circuit in LT-Spice.
>
>But I've never used spice, LT or otherwise, so I was hoping to find an
>example of a solar panel equivalent circuit that I could import, then add
>the rest of the circuit, which is pretty simple.
>
>Can someone suggest where I would find such a file? It would be something
>like a 5V panel, 200mA.
>
Wild guess to open discussion: a string of silicon power diodes with a
parallel current source that represents illumination.
LT Spice is great. It shouldn't take long to enter and run a circuit;
ask here if it doesn't work. There are no doubt a lot of tutorials on
youtube.
Reply by Peabody●May 25, 20212021-05-25
I'm working on a TP4056-based 1S LIPO solar charger which includes a load
sharing (aka power path) function. But I don't have a panel to test with.
So I'd like to simulate the circuit in LT-Spice.
But I've never used spice, LT or otherwise, so I was hoping to find an
example of a solar panel equivalent circuit that I could import, then add
the rest of the circuit, which is pretty simple.
Can someone suggest where I would find such a file? It would be something
like a 5V panel, 200mA.