<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">I’m going to try both, the post simulation calculation and the 1st order lag.<div class="">Thanks to you Mike and have a nice weekend.<br class=""><div><blockquote type="cite" class=""><div class="">Am 19.05.2017 um 17:25 schrieb Michael J McCann <<a href="mailto:mjmccann@ieee.org" class="">mjmccann@ieee.org</a>>:</div><br class="Apple-interchange-newline"><div class="">
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<font size="+1" class="">RMS Value: <br class="">
In a dynamic system simulation you can readily generate an
instantaneous power value that can be recorded simply by using a
volts*current product or any other dimensionally equivalent
product.<br class="">
If however you want to do some averaging of the power level then
you must have a record of that instantaneous value and do the
averaging over the length of the record, which your request
implies you have and therefore implies a post processing
operation. You can partition the record into whatever shorter
lengths you want and generate true RMS values over those time
segments. But beware, if the model is simulating a fixed
frequency (e.g.50Hz) power system then the periods must be
integer multiples of the cycle time.<br class="">
<br class="">
If you want a value that appears like a metered value might
appear then you can put the product term through a 1st order lag
(exponentially weighted effect)<br class="">
G(s)=1/(1+sT) // xdot=(1/T)*(Input- x); <br class="">
and imitate the behaviour of a meter. All you have to do is chose
the "time constant",T, of the meter. e.g several cycles.<br class="">
<br class="">
The MATLAB (2017a) Moving RMS includes the exponential weighting
option and the true moving window version as well. I expect it
could be replicated in XCOS with a SciLab function.<br class="">
<br class="">
Mike.<br class="">
==================<br class="">
</font><br class="">
<div class="moz-cite-prefix">On 19/05/2017 05:51,
Sachverständigenbüro Niedermaier Holger wrote:<br class="">
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<blockquote cite="mid:883477F0-56E2-46DC-B3E6-1320A983602F@bayern-mail.de" type="cite" class="">
<pre wrap="" class="">Dear all,
by simulating an electrical power circuit I’d like to plot the voltage and the current over time, which is easy to perform by using the scope block.
In addition to the signal recorded I’d like to calculate the TRMS value of the plotted current and voltage signal.
Unfortunately Xcos does not include a TRMS block like e.g. Simulink do.
Because I’m so far not so familiar with Xcos and Scilab I’d like to ask the community for support.
Does anybody have a good idea or advise how to get the TRMS value of the recorded signal?
Thanks and nice weekend
Holger
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</pre>
</blockquote>
<br class="">
<pre class="moz-signature" cols="72">--
Dr.M.J.McCann,MJMcCann-Consulting
</pre>
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