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Modeling half cells in SAM
- Nick.Riedel
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10 Feb 2020 02:34 #7957
by Nick.Riedel
Modeling half cells in SAM was created by Nick.Riedel
I am wondering if SAM currently has the capability to simulate electrical performance and shade losses of half cut cell modules (i.e. modules w/ 144 cells of 78 mm x 156 mm). I am running SAM 2018.11.11 and as far as I can tell, the answer is "not yet". Please correct me if I am wrong.
The only discussion I've found on this topic is from 2 years ago and there are no responses:
sam.nrel.gov/forum/forum-general/1939-modeling-split-cell-144-cells-modules.html#6050
Thanks.
The only discussion I've found on this topic is from 2 years ago and there are no responses:
sam.nrel.gov/forum/forum-general/1939-modeling-split-cell-144-cells-modules.html#6050
Thanks.
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- pgilman
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- Posts: 5423
10 Feb 2020 10:16 #7960
by pgilman
Replied by pgilman on topic Modeling half cells in SAM
Hi Nicholas,
SAM's Detailed Photovoltaic model does not model individual cells, so it doesn't distinguish between modules with full and half cells. The shading models either model shading as a reduction in the beam irradiance over the entire array, or for self-shading, make some assumptions about the layout of cells in the module based on a conventional full cell module with three blocking diodes.
The "CEC Module Model with User Entered Parameters" option uses the number of cells in series in the numerical solution to calculate an I-V curve from module parameters. (It uses the value to determine initial guess values for the solution.) If you use that option to enter parameters for a module with half cells, I have found that the solver works best if you use the number of whole cells for the "Number of cells in series" input, so for a module with 144 half cells, you would enter 72 as the number of cells.
Best regards,
Paul.
SAM's Detailed Photovoltaic model does not model individual cells, so it doesn't distinguish between modules with full and half cells. The shading models either model shading as a reduction in the beam irradiance over the entire array, or for self-shading, make some assumptions about the layout of cells in the module based on a conventional full cell module with three blocking diodes.
The "CEC Module Model with User Entered Parameters" option uses the number of cells in series in the numerical solution to calculate an I-V curve from module parameters. (It uses the value to determine initial guess values for the solution.) If you use that option to enter parameters for a module with half cells, I have found that the solver works best if you use the number of whole cells for the "Number of cells in series" input, so for a module with 144 half cells, you would enter 72 as the number of cells.
Best regards,
Paul.
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