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<p>Chaminda,</p>
<p> I did not have a chance to look deeply into why you are getting
different results if you split up your two PV simulations into two
projects. However, I did notice a few things about your project in
looking at it.</p>
<p> First, I do not think it is adviseable to have two instances of
Type99 that are both reading from the same file. This might be the
cause of the different results when you move one of the PVs to its
own project. Either make a copy of the weather file and give it a
different name or just use one instance of Type99 that feeds its
outputs to both of your PV simulations.</p>
<p> Second, there are errors and inconsistencies in the solar
radiation that is passed to the PV. In all cases the total
radiation input is connected. However, in some case the beam
radiation is connected from another component's output and in
other cases it is not. The diffuse radiation input is not
connected. This means that the PVs think that there is 0 diffuse
radiation at all times. It is very important to be consistent
about the radiation inputs to the PV and to make sure that all
three (total, diffuse, and beam are all being passed to the PV
from another Type.</p>
<p> Third, while you can use Type30 as an approximation for shading
on a PV it assumes that the impact of shading a PV is linear (i.e.
if you shade half the PV you will get half the power output that
you would from an unshaded PV). This linear shading impact is
often not the case with PVs. There is an alternative model
(Type551) in the TESS Electrical library that offers a somewhat
improved model for shading PVs.</p>
<p>kind regards,</p>
<p> David</p>
<p> <br>
</p>
<br>
<div class="moz-cite-prefix">On 05/27/2016 04:41, Chaminda Ranaweera
via TRNSYS-users wrote:<br>
</div>
<blockquote cite="mid:web-78131973@tu-clausthal.de" type="cite">Hello,
<br>
<br>
I made analysis for two surfaces. South and West. When I run both
West and South programs run in same Trnsys file, then I get wrong
result (Different result). But when I run it in two different
files, then I get another result. Can anyone explain me the reason
for this? Please help me. Trnsys Hotline is no longer helping to
me. I think this problem is due to inherent problem of Trnsys.
Before sselling the product, they were replying to university. Now
they are silent.
<br>
<br>
Can anyone help me. Actually I am doing my final modelling for
thesis. Nobody will give money to me to go for training on Trnsys
and nobody knows whether it is useful or not.
<br>
<br>
(I hereby attach Program File and results)
<br>
<br>
Thank You,
<br>
<br>
Chaminda Ranaweera
<br>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
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<pre class="moz-signature" cols="72">--
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
22 North Carroll Street - suite 370
Madison, WI 53703 USA
P:+1.608.274.2577
F:+1.608.278.1475
<a class="moz-txt-link-abbreviated" href="mailto:d.bradley@tess-inc.com">d.bradley@tess-inc.com</a>
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