<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type">
</head>
<body bgcolor="#ffffff" text="#000000">
There isn't any way of backing up in time in a TRNSYS simulation. I've
given a good bit of thought to how you might do this and have never
really figured out how to solve the problem. Fundamentally, when you
start a simulation, there is a time when the performance is dominated
to a smaller or larger extent by the initial values (initial
temperatures profiles through walls, etc.). With only a 24 hour run, I
would worry that the initial values would dominate too much.<br>
Kind regards,<br>
David<br>
<br>
<br>
leen peeters wrote:
<blockquote cite="mid:C0F410E491314D36AD6757391D5AE880@mech.kuleuven.be"
type="cite">
<meta http-equiv="Content-Type" content="text/html; ">
<meta content="MSHTML 6.00.6000.16788" name="GENERATOR">
<style></style>
<div><font face="Arial" size="2">Dear all,</font></div>
<div> </div>
<div><font face="Arial" size="2">here is a question from a student
using TRNSYS for his master's thesis:</font></div>
<blockquote
style="border-left: 2px solid rgb(0, 0, 0); padding-right: 0px; padding-left: 5px; margin-left: 5px; margin-right: 0px;">
<div
style="font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal;">-----
Original Message ----- </div>
<div
style="background: rgb(228, 228, 228) none repeat scroll 0%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial; font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal;"><b>From:</b>
<a moz-do-not-send="true" title="koen.bogaerts@student.kuleuven.be"
href="mailto:koen.bogaerts@student.kuleuven.be">Koen Bogaerts</a> </div>
<div
style="font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal;"><b>To:</b>
<a moz-do-not-send="true" title="Leen.Peeters@mech.kuleuven.be"
href="mailto:Leen.Peeters@mech.kuleuven.be">Leen Peeters</a> </div>
<div
style="font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal;"><b>Sent:</b>
Wednesday, February 11, 2009 10:20 AM</div>
<div
style="font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal;"><b>Subject:</b>
mail trnsys</div>
<div><br>
</div>
<div>Dear all,<br>
<br>
I'm trying to create a Model Predictive Control (MPC) for a micro-CHP
unit. (so a control stategy that bases it's future actuator signal on
what it expects to occur) <br>
Each timestep a prediction of the next 24 hours should be made. After
an optimization of this prediction horizon, the optimized input values
for that timefrane are passed to the TRNSYS model to determine the
CHP's working startegy for those 24 h.. <br>
<br>
<font face="Arial" size="2">I have my main building model in
TRNSYS, i.e. the model that recieves the working strategy and thus acts
as the real building.</font></div>
<div><font face="Arial" size="2">I wondered whether there is a way
to use the same building model for the prediction as well. To so so,
there might be two options:</font></div>
<div> </div>
<div><font face="Arial" size="2">either: at midnight, making a copy
of the TRNSYS main model (i.e.a copy that has the same values for the
physical state variables as the main model at that timestep) and add
some noise to weather data and internal gains, use that copy on a
larger timestep and base the predictionon on that</font></div>
<div> </div>
<div><font face="Arial" size="2">either: use the main model for the
prediction as well, but assume you start a prediction at timestep A,
run the model till timestep B (24 hours later), return the simulation
back to timestep A and run the main simulation ,....</font></div>
<div> </div>
<div><font face="Arial" size="2">Is one of those an option in
TRNSYS? </font></div>
<div> </div>
<div>Regards,<br>
<br>
---<br>
Koen Bogaerts<br>
University of Leuven, Belgium<br>
</div>
</blockquote>
<br>
<br>
<font face="Arial" size="2">Disclaimer: <a moz-do-not-send="true"
href="http://www.kuleuven.be/cwis/email_disclaimer.htm">http://www.kuleuven.be/cwis/email_disclaimer.htm</a>
for more information.</font>
<br>
<br>
<pre wrap="">
<hr size="4" width="90%">
_______________________________________________
TRNSYS-users mailing list
<a class="moz-txt-link-abbreviated" href="mailto:TRNSYS-users@cae.wisc.edu">TRNSYS-users@cae.wisc.edu</a>
<a class="moz-txt-link-freetext" href="https://www-old.cae.wisc.edu/mailman/listinfo/trnsys-users">https://www-old.cae.wisc.edu/mailman/listinfo/trnsys-users</a>
</pre>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
***********************************************************************
Thermal Energy System Specialists (TESS), LLC
David BRADLEY 22 N. Carroll Street - Suite 370
Partner Madison, WI 53703
USA
P: +1.608.274.2577
F: +1.608.278.1475
E-mail: <a class="moz-txt-link-abbreviated" href="mailto:bradley@tess-inc.com">bradley@tess-inc.com</a>
Web Pages: <a class="moz-txt-link-freetext" href="http://www.tess-inc.com">http://www.tess-inc.com</a> and <a class="moz-txt-link-freetext" href="http://www.trnsys.com">http://www.trnsys.com</a>
***********************************************************************</pre>
</body>
</html>