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<p>Michel,</p>
<p> An hour time step is almost guaranteed not to work. Controllers
can make one decision per time step. That kind of frequency of
decision making can very easily lead to empty tanks, overcharged
batteries etc. You should be working with time steps between 1 and
5 minutes. Needing multiple days to run TRNOpt optimizations is
not uncommon at all.<br>
</p>
<p> The difference between the two solar plots would suggest that
there is some problem with the way the solar radiation data is
being read and processed. It would help to know what components
you are using to read and process the data and what version of
Trnsys you are using.</p>
<p>kind regards,</p>
<p> David</p>
<p><br>
</p>
<br>
<div class="moz-cite-prefix">On 10/12/2018 09:09, Michel Tamarzians
via TRNSYS-users wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAPCNZs7TRhJ4Wt0uYo92PH7s=+i0qvncG=acP6vAE99X=yDQKw@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=utf-8">
<div dir="ltr">
<div>Dear, <br>
</div>
<div><br>
</div>
<div>I am working on a simulation of a stand-alone
pv-hydrogen-battery system. I am using the mastercontroller,
"Unit 36", to control the power flow between the solar,
battery, electrolyzer, fuel cell and load. Unfortunately when
running the simulation for a whole year with timestep of 1
hour and the successive solver and differential equation
algorithm of Heun or Euler it gives me convergence issues and
stops the simulation. Ofcourse I can set the limit for the
errors so high but then the simulation finishes with really
strange results. For example even the solar energy coming in
is totally changed throughout the year. If I make the timestep
smaller, such as 0.01 then it works kinda oke but still the
solar energy curve is totally different then it should be when
nothing would be connected to it. See the two graphs added of
the solar energy curve throughout the year.....<br>
</div>
<div>Does anybody has a clue on how to tackle this convergence
issue? Do I need to make the stepsize even smaller? But then
it takes so long, that when I want to optimize my system with
TRNOpt it takes probably about 3 days per simulation which is
ridiculous by my understanding.</div>
<div>Can someone please help me out or point me towards a
direction on where to find a solution?</div>
<div><br>
</div>
<div>Thanks in advance!</div>
<div><br>
</div>
<div>Kind regards, <br>
</div>
<div><br>
</div>
<div>Michel<br>
</div>
</div>
<br>
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<br>
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<pre class="moz-signature" cols="72">--
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
3 North Pinckney Street - suite 202
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>
<a class="moz-txt-link-freetext" href="http://www.tess-inc.com">http://www.tess-inc.com</a>
<a class="moz-txt-link-freetext" href="http://www.trnsys.com">http://www.trnsys.com</a></pre>
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