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Powered by Question2AnswerAnswered: Add component to Library Plecs Blockset
http://forum.plexim.com/683/add-component-to-library-plecs-blockset?show=1914#a1914
Hi,<br />
<br />
I know this question has been resolved, but just for future reference, there is now a video explaining how to create a new user library component in PLECS Blockset -- <a href="https://youtu.be/jRE0j-7x-08" rel="nofollow">https://youtu.be/jRE0j-7x-08</a><br />
<br />
Regards,<br />
Manuhttp://forum.plexim.com/683/add-component-to-library-plecs-blockset?show=1914#a1914Thu, 14 Nov 2019 20:29:51 +0000Answered: What does error evaluating parameter 'Resistance' mean?
http://forum.plexim.com/1822/what-does-error-evaluating-parameter-resistance-mean?show=1847#a1847
PLECS does not accept SI prefixes, so the "k" is not recognized. This is because we allow for the user to use custom variables for value assignment, including just the letter k. You could write the resistance value as 100000, 100e3, 1e6, or assign the value to a variable, such as R.http://forum.plexim.com/1822/what-does-error-evaluating-parameter-resistance-mean?show=1847#a1847Tue, 05 Nov 2019 23:37:57 +0000How to get Single-Phase SST model
http://forum.plexim.com/1791/how-to-get-single-phase-sst-model
<p>I have searched for it in Demo Models but couldn't find it. It is published on Youtube here <a rel="nofollow" href="https://www.youtube.com/watch?reload=9&v=-J8S3EFktZg">https://www.youtube.com/watch?reload=9&v=-J8S3EFktZg</a></p>http://forum.plexim.com/1791/how-to-get-single-phase-sst-modelThu, 31 Oct 2019 21:01:10 +0000Answered: Running Plecs on multi-core machine
http://forum.plexim.com/428/running-plecs-on-multi-core-machine?show=1789#a1789
<p>hi </p><p>I wrote a workarund in python to do that, it generate more variants of the same simulation and then run parallel with gui automatization</p><p> you can find on my github <a rel="nofollow" href="https://github.com/tinix84/pyplecs">https://github.com/tinix84/pyplecs</a></p>http://forum.plexim.com/428/running-plecs-on-multi-core-machine?show=1789#a1789Thu, 31 Oct 2019 14:19:21 +0000Answered: Are there other ways to speed up the simulation?
http://forum.plexim.com/819/are-there-other-ways-to-speed-up-the-simulation?show=1788#a1788
<p>hi </p><p>I wrote a workarund in python to do that, it generate more variants of the same simulation and then run parallel with gui automatization</p><p> you can find on my github <a rel="nofollow" href="https://github.com/tinix84/pyplecs">https://github.com/tinix84/pyplecs</a></p>http://forum.plexim.com/819/are-there-other-ways-to-speed-up-the-simulation?show=1788#a1788Thu, 31 Oct 2019 14:18:58 +0000Answered: Run multiple simulations in parallel using XML-RPC
http://forum.plexim.com/874/run-multiple-simulations-in-parallel-using-xml-rpc?show=1786#a1786
<p>hi I wrote a workarund in python to do that you can find on my github <a rel="nofollow" href="https://github.com/tinix84/pyplecs">https://github.com/tinix84/pyplecs</a></p>http://forum.plexim.com/874/run-multiple-simulations-in-parallel-using-xml-rpc?show=1786#a1786Thu, 31 Oct 2019 11:55:09 +0000Answered: current source modeling in the plecs
http://forum.plexim.com/1739/current-source-modeling-in-the-plecs?show=1785#a1785
<p>hi </p><p>This is physical impossible if you try to force a current step in the inductor, you can solve adding the resistive part of inductor, this will equal the fluxes. it does not depend from simulation tool</p><p>Just as reminder the transformer resistance in series is what you measure at the switching frequency not the DC one.</p><p>Unfortunately PLECS simulation miss some model and I cannot launch it</p><p></p>http://forum.plexim.com/1739/current-source-modeling-in-the-plecs?show=1785#a1785Thu, 31 Oct 2019 11:53:58 +0000How can we include parasitic capacitance in MOSFET?
http://forum.plexim.com/1778/how-can-we-include-parasitic-capacitance-in-mosfet
I'm modelling synchronous Buck Converter in discontinuous conduction mode and I want to check the ringing effect caused due to the parasitic capacitance of semiconductor device. But I'm not able to incorporate this in semiconductor model.http://forum.plexim.com/1778/how-can-we-include-parasitic-capacitance-in-mosfetWed, 30 Oct 2019 15:24:20 +0000Answered: AC analysis tool prematurely terminating
http://forum.plexim.com/1724/ac-analysis-tool-prematurely-terminating?show=1765#a1765
<p>Hello,</p><p>The first thing I noticed is that your model in its current form does not run do to an error message "cyclic behavior during switching". To better understand what this means, I recommend you see our website post on the topic: <a href="https://www.plexim.com/support/solutions/146" rel="nofollow">https://www.plexim.com/support/solutions/146</a>. I was able to get your model running simply by increasing the "Diode turn-on threshold" solver setting from 0 to 1e-3. The small-signal analysis tools should then be able to converge. Note that for your model, you might consider the Impulse Response Analysis tool for a much faster result. I attached a plot capture below showing the results I saw when using this. Regarding the settings you emboldened above, did you review our documentation about what they do? I hope this helps!</p><p>Regards,</p><p>Kris</p><p> </p><p><img alt="" src="http://forum.plexim.com/?qa=blob&qa_blobid=15738433047759109713" style="height:546px; width:462px"></p>http://forum.plexim.com/1724/ac-analysis-tool-prematurely-terminating?show=1765#a1765Tue, 29 Oct 2019 19:28:15 +0000Answered: Accessing .csv data in PLECS standalone
http://forum.plexim.com/1742/accessing-csv-data-in-plecs-standalone?show=1762#a1762
Hello,<br />
<br />
Yes, please see the method demonstrated in this thread: <a href="https://forum.plexim.com/11/is-it-possible-to-import-waveform-data-into-plecs?show=12#a12" rel="nofollow">https://forum.plexim.com/11/is-it-possible-to-import-waveform-data-into-plecs?show=12#a12</a><br />
<br />
Regards,<br />
<br />
Krishttp://forum.plexim.com/1742/accessing-csv-data-in-plecs-standalone?show=1762#a1762Tue, 29 Oct 2019 18:41:51 +0000Controlling the thyristors of the B6C rectifier with 6-Pulse Generator?
http://forum.plexim.com/1699/controlling-the-thyristors-rectifier-with-pulse-generator
Hello,<br />
<br />
I need a driver for a B6C (6 thyristors) and came across the 6 Pulse Generator. Now I have the problem that I get no gate current at each 2 thyristors. At "phi" I have a Pulse Generator, connected to "enable" a constant signal. What value do I enter with enable?<br />
Under "alpha" I have my steering angle in rad. Am I on the right track or are I missing something?<br />
<br />
Behind the 6 pulse generator I have a signal demultiplexer with 6 outputs. From the top I usually have no signal at the output 4 and 5.<br />
<br />
Hope you understand my problem. Excuse my bad english.<br />
<br />
Thanks for your help!http://forum.plexim.com/1699/controlling-the-thyristors-rectifier-with-pulse-generatorTue, 22 Oct 2019 07:41:11 +0000Answered: How can i measure Torque and speed at the same time?
http://forum.plexim.com/1658/how-can-i-measure-torque-and-speed-at-the-same-time?show=1675#a1675
Sure it is. Keep in mind that torque is a through-quantity so you need to place a Torque Sensor in series with your mechanical connection, while speed is an across-quantity so you need to place your Speed Sensor in parallel with the node of interest. I hope this helps!<br />
<br />
Krishttp://forum.plexim.com/1658/how-can-i-measure-torque-and-speed-at-the-same-time?show=1675#a1675Fri, 18 Oct 2019 20:52:04 +0000Answered: How to measure delay between input and output signals?
http://forum.plexim.com/1580/how-to-measure-delay-between-input-and-output-signals?show=1674#a1674
Hello,<br />
<br />
Can you elaborate on your circuit/amplifier design? I might suggest you read the How PLECS Works chapter of our User Manual. Basically, after the setup of the physical model, PLECS determines the execution order of the block diagram where the physical model is treated as a single atomic subsystem of the block diagram. But any results the user wants to monitor in a Scope, Display block, etc are presented simultaneously. Further, the Op-Amp component, for example, is nothing more than an ideal gain under the mask. Therefore, it isn't possible to measure a time delay based on the native implementation of your circuit.<br />
<br />
Regards,<br />
<br />
Krishttp://forum.plexim.com/1580/how-to-measure-delay-between-input-and-output-signals?show=1674#a1674Fri, 18 Oct 2019 20:31:21 +0000Answered: Is there any PLECS workshops or seminars planned in India ??
http://forum.plexim.com/1563/is-there-any-plecs-workshops-or-seminars-planned-in-india?show=1593#a1593
Hello,<br />
<br />
Not currently, but please contact info@plexim.com about your interest and your affiliation.<br />
<br />
Regards,<br />
Krishttp://forum.plexim.com/1563/is-there-any-plecs-workshops-or-seminars-planned-in-india?show=1593#a1593Fri, 11 Oct 2019 08:46:37 +0000Answered: PLECS help viewer display problem
http://forum.plexim.com/1528/plecs-help-viewer-display-problem?show=1556#a1556
you need to ask this question from support not from community side but for sure it's your browser issue.http://forum.plexim.com/1528/plecs-help-viewer-display-problem?show=1556#a1556Mon, 07 Oct 2019 12:05:14 +0000Does this method work for frequency-domain plots?
http://forum.plexim.com/1553/does-this-method-work-for-frequency-domain-plots
I have implemented the above example and, while it works fine for time-domain signals, it seems to fail when a frequency domain signal with frequency values up to MHz range are read from the .csv file. What I would like to know is if there is a method to use the plecs scope to plot any arbitrary signal? It would be nice to use it to plot measured and simulated values and see them on the same scope.<br />
<br />
Can anyone provide some suggestions?<br />
<br />
Thankshttp://forum.plexim.com/1553/does-this-method-work-for-frequency-domain-plotsSat, 05 Oct 2019 23:16:12 +0000Answered: From datasheet how to find .xml for plecs software - thermal description (SEMIKRON IGBT)
http://forum.plexim.com/1524/from-datasheet-plecs-software-thermal-description-semikron?show=1548#a1548
Hello,<br />
<br />
Have you reviewed our tutorial videos on this topic on our website?<br />
<br />
Some manufacturers provide the thermal description (.xml) files for PLECS already. For the rest, you will need to request the data from them or import the data yourself. For example, for the SKiiP 01NAC066V3 IGBT Six-Pack module, Figure 1 in the datasheet provides Conduction Loss curves for two temperatures, Figure 5 provides Turn-On and Turn-Off curves at one temperature (you should request temperature-dependence switching loss data from the vendor) and Figure 8 provides the thermal impedance curves.<br />
<br />
Let me know if you have specific questions about this.<br />
<br />
Regards,<br />
<br />
Krishttp://forum.plexim.com/1524/from-datasheet-plecs-software-thermal-description-semikron?show=1548#a1548Sat, 05 Oct 2019 10:23:46 +0000Answered: how to replace the PV Inverter in MATLAB with Plecs Blockset PV Inverter
http://forum.plexim.com/1471/how-replace-the-inverter-matlab-with-plecs-blockset-inverter?show=1488#a1488
Thank you for posting the image, this was helpful. It is not possible to directly interface physical signals in PLECS to physical SimScape signals. The information needs to be relayed via control signals. You will need to measure electrical quantities with meters in Simscape and pass those (control) signals into the inputs of the PLECS Circuit block. Further, you will need to use PLECS "Signal Inport" and "Signal Outport" blocks inside of the PLECS block, rather than "Electrical Port" blocks. Exiting the PLECS Circuit block, you will need to then measure the inverter three-phase outputs with Voltmeters and via the Signal Outport blocks, drive controlled sources (i.e., voltage) and connect these to the rest of the electrical system in Simscape.<br />
<br />
By the way, you can model the complete system shown in your image inside of PLECS- have you considered doing this? It's more efficient than to combine PLECS and Simscape physical system blocks.<br />
<br />
Regards,<br />
<br />
Krishttp://forum.plexim.com/1471/how-replace-the-inverter-matlab-with-plecs-blockset-inverter?show=1488#a1488Fri, 27 Sep 2019 15:31:56 +0000Answered: start saving waveform data only after a specified time
http://forum.plexim.com/1485/start-saving-waveform-data-only-after-a-specified-time?show=1486#a1486
You can place the scope in an enabled subsystem and use a Step block to enable the subsystem (and hence the scope) at the desired simulation time.http://forum.plexim.com/1485/start-saving-waveform-data-only-after-a-specified-time?show=1486#a1486Fri, 27 Sep 2019 14:59:32 +0000Answered: How go give one year solar irradiance and ambient temperature data to the grid connected solar PV System
http://forum.plexim.com/1469/solar-irradiance-ambient-temperature-connected-solar-system?show=1479#a1479
<p>Hello,</p><p>You can use lookup tables to include external/predefined data into your simulation. Please see this forum thread for an explanation of the solution: <a rel="nofollow" href="https://forum.plexim.com/11/is-it-possible-to-import-waveform-data-into-plecs">https://forum.plexim.com/11/is-it-possible-to-import-waveform-data-into-plecs</a>.</p><p>Thanks,<br>Kris</p>http://forum.plexim.com/1469/solar-irradiance-ambient-temperature-connected-solar-system?show=1479#a1479Thu, 26 Sep 2019 16:00:04 +0000Answered: How to implement PI controller for Buck converter?
http://forum.plexim.com/1450/how-to-implement-pi-controller-for-buck-converter?show=1465#a1465
Hello,<br />
<br />
The issue is with the 'Output values' setting of the Symmetrical PWM block. While you used the default settings, these are configured for if you are then using comparison logic of greater than and less than zero to determine the conduction state of upper and lower switches. However, the actual MOSFET turns on when a non-zero value is applied to the gate input, and off for a value of zero. Since the PWM has output settings for [-1 1] for off and on, respectively, the MOSFET is actually always on in your model. If you change the output setting to [0 1] this should fix your issue. Separately, I noticed you had included thermal descriptions for the MOSFET and diode, but are you aware that you will also need to add a heatsink on top of these two components to enable the calculation of losses?<br />
<br />
Let me know if we can help with anything else.<br />
<br />
Regards,<br />
Krishttp://forum.plexim.com/1450/how-to-implement-pi-controller-for-buck-converter?show=1465#a1465Wed, 25 Sep 2019 16:40:30 +0000Error "Solver has missed a sample hit (0.0055) in task [0.0005, 0]."
http://forum.plexim.com/1462/error-solver-has-missed-a-sample-hit-0-0055-in-task-0-0005-0
Hi.<br />
<br />
I have 10e-6 set as fixed step size in solver and 500e-6 as sample time for one of the subsystems (treated as atomic unit). With these settings I am facing this fatal error as seen in the image attached.<br />
<br />
Please help.<br />
<br />
Bhavani.http://forum.plexim.com/1462/error-solver-has-missed-a-sample-hit-0-0055-in-task-0-0005-0Wed, 25 Sep 2019 13:17:49 +0000Error regarding "non-sampled zero crossings"
http://forum.plexim.com/1461/error-regarding-non-sampled-zero-crossings
Hi.<br />
<br />
I have got the error message (see below) while when I changed the simulation from variable step size to fixed step size. I do not want to run my simulation by changing sample time. And I do not know what is refine factor. Please help<br />
<br />
Error message: "Maximum number of iterations exceeded during evaluation of non-sampled zero crossings. Please try reducing the sample time or increasing the refine factor."<br />
<br />
<br />
<br />
Bhavanihttp://forum.plexim.com/1461/error-regarding-non-sampled-zero-crossingsWed, 25 Sep 2019 11:56:31 +0000Answered: How do I measure active and reactive power consumption in my network using plecslib?
http://forum.plexim.com/1430/measure-active-reactive-power-consumption-network-plecslib?show=1435#a1435
Hello,<br />
<br />
There is not a block that will calculate P and Q for you automatically, you will need to apply this logic yourself. But we have several demo models that show how this can be done, for example the "Microgrid in Island Operation", "STATCOM Cascaded H-Bridge Converter", and "Neutral-Point Clamped Converter" models. I also attached a screenshot from the NPC demo model where the P and Q equations are implemented using the measured three-phase voltage and current waveforms. Let me know if you have further questions on this topic.<br />
<br />
Regards,<br />
<br />
Krishttp://forum.plexim.com/1430/measure-active-reactive-power-consumption-network-plecslib?show=1435#a1435Thu, 19 Sep 2019 23:19:22 +0000Answered: Saving Complete Simulation
http://forum.plexim.com/1432/saving-complete-simulation?show=1434#a1434
Hello,<br />
<br />
No, unfortunately this is not possible- it does need to be done on a scope by scope basis. Alternatively you can route all of the signals of interest to a To File block and then later load those into a set of Lookup Table blocks whose outputs can be plotted in a Scope(s). Please see <a href="https://forum.plexim.com/11/is-it-possible-to-import-waveform-data-into-plecs" rel="nofollow">https://forum.plexim.com/11/is-it-possible-to-import-waveform-data-into-plecs</a> for an example of the latter.<br />
<br />
Regards,<br />
<br />
Krishttp://forum.plexim.com/1432/saving-complete-simulation?show=1434#a1434Thu, 19 Sep 2019 17:38:13 +0000Error: accessing blockset
http://forum.plexim.com/1425/error-accessing-blockset
Hi<br />
<br />
I am trying to open my Plecs model which was made in the blockset mode with matlab. The attached error message is popping up and Plecs blocks are not accessible.<br />
<br />
Kindly suggest how to remedy this?<br />
<br />
<br />
<br />
Thanks<br />
<br />
Snehahttp://forum.plexim.com/1425/error-accessing-blocksetThu, 19 Sep 2019 01:33:48 +0000Answered: Negative switching or conduction losses are cropped
http://forum.plexim.com/1396/negative-switching-or-conduction-losses-are-cropped?show=1398#a1398
Hello,<br />
<br />
It appears that these are not the official thermal descriptions provided by the manufacturer on their website. We would recommend that you use those models if possible.<br />
<br />
It is also not easy to fully diagnose the issue without having your circuit model that shows the error message. I suspect, however, the issue is a numerical one. For example, with the thermal description you attached for C2M0080170P, the Conduction Loss current axis has a value of 6.133300000000001e-15. You should change this to 0. Also, the datapoint at 25C and 10A is 0.8436100000000001. This should probably be truncated to 0.84361. Further, your thermal impedance coefficients have a complexity that may lead to a numerically stiff system.<br />
<br />
Let me know if this helps.<br />
<br />
Krishttp://forum.plexim.com/1396/negative-switching-or-conduction-losses-are-cropped?show=1398#a1398Fri, 13 Sep 2019 18:31:09 +0000Can we get accurate frequency sweep results for converters with a variable switching frequency using Analysis tools?
http://forum.plexim.com/1383/frequency-converters-variable-switching-frequency-analysis
<p>Hi there,</p><p>I am trying to obtain the frequency response of a closed-loop buck converter. I am using a boundary control method to regulate output voltage of the buck converter.In this case, <strong>switching frequency is varying slightly in steady state operation( sometimes 6.944 kHz and sometimes 7.352 kHz for given operating conditions)</strong>. I tried Ac sweep,impulse response analysis method as well as Mutitone analysis to obtain the frequency response from Vref to Vc.I used a value close to the switching period as the system period where ever it needed but i was unsuccessful in getting the results that i expected and mostly solutions did not even converge.</p><p>Could you please advice on how to use analysis tools for a converter with variable switching frequency to obtain the frequency response? Is there any demo model that i can follow and understand. Really appreciate your help on this. </p><p>Thanks</p><p>Dilan</p>http://forum.plexim.com/1383/frequency-converters-variable-switching-frequency-analysisWed, 11 Sep 2019 05:14:09 +0000Answered: Metal Oxide Varistor (MOV)
http://forum.plexim.com/1330/metal-oxide-varistor-mov?show=1374#a1374
Hello,<br />
<br />
The Piecewise Linear Resistor is exactly that, a set of predefined I-V pairs. But the MOV implementation in the referenced thread above allows for the calculation of time-varying, non-preset resistance values. Does that make sense?<br />
<br />
Thanks,<br />
Krishttp://forum.plexim.com/1330/metal-oxide-varistor-mov?show=1374#a1374Tue, 10 Sep 2019 04:42:38 +0000Saturable Transformer (2-Windings)
http://forum.plexim.com/1331/saturable-transformer-2-windings
Hi.<br />
<br />
I am trying to simulate the saturable transformer and I have a query related to that.<br />
<br />
There are two fields - 'Magnetizing current values' and 'Magnetizing flux values'. I need help in entering these fields. Are they modeling only the linear portion of B-H curve? How to check if it is getting saturated.<br />
<br />
Also data sheet does not provide direct current to flux values. It may have current vs voltage values. So can I get some documents that explains me to find current vs flux values.?<br />
<br />
<br />
<br />
Bhavanihttp://forum.plexim.com/1331/saturable-transformer-2-windingsWed, 28 Aug 2019 13:01:03 +0000Answered: Can V*I be used to calculate switching losses of a Limited di/dt MOSFET?
http://forum.plexim.com/1305/can-be-used-to-calculate-switching-losses-of-limited-mosfet?show=1316#a1316
Hello,<br />
<br />
Correct, we do not recommend that you use the voltage and current waveforms of the two switch components with limited turn-on and turn-off for loss calculation. The peak magnitudes of overvoltage and overcurrent waveforms are accurately calculated, but the higher order growth and decay curves in the real device's behavior are highly dependent on the external circuitry so we don't want you to assume your model corresponds to a hardware implementation. The standard MOSFET should be used for loss calculation with a thermal description and cooling circuit.<br />
<br />
Regards,<br />
<br />
Krishttp://forum.plexim.com/1305/can-be-used-to-calculate-switching-losses-of-limited-mosfet?show=1316#a1316Fri, 23 Aug 2019 17:58:38 +0000Answered: How to generate unipolar PWM for boost converter using C-script?
http://forum.plexim.com/1306/how-generate-unipolar-pwm-for-boost-converter-using-script?show=1314#a1314
Hello,<br />
<br />
Have you looked at the demo model included in PLECS called "Inverter with C-Script-Based PWM Modulator"? You can view and modify the C-Script based modulator for your purpose.<br />
<br />
Regards,<br />
<br />
Krishttp://forum.plexim.com/1306/how-generate-unipolar-pwm-for-boost-converter-using-script?show=1314#a1314Fri, 23 Aug 2019 17:45:03 +0000Answered: How to set the Rise time and Fall time of the MOSFET di/dt model
http://forum.plexim.com/1312/how-to-set-the-rise-time-and-fall-time-of-the-mosfet-di-dt-model?show=1313#a1313
Hello,<br />
<br />
The screenshots are helpful, but it is much easier to give feedback if you attach your model. Anyway, please see the help description for the "IGBT with Limited di/dt" component as there are example plots showing you what the rise and fall times are graphically. This should help you to verify that the model is correct.<br />
<br />
Thank you,<br />
<br />
Krishttp://forum.plexim.com/1312/how-to-set-the-rise-time-and-fall-time-of-the-mosfet-di-dt-model?show=1313#a1313Fri, 23 Aug 2019 17:40:55 +0000State discontinuity after switching
http://forum.plexim.com/1302/state-discontinuity-after-switching
I'm simulating half bridge resonant converter. It works fine when I use diode in rectifier circuit but as soon as I use MOSFET it shows the state discontinuity error. I tried to simulate separately a center tapped rectifier which was working fine with diode but as soon as use MOSFET it shows the same error. I'm giving complementary gate pulse to both the signal. Where is the error and what shall I do to resolve this error?http://forum.plexim.com/1302/state-discontinuity-after-switchingWed, 21 Aug 2019 13:05:04 +0000Answered: How to model the losses of MOSFET with Diode?
http://forum.plexim.com/1296/how-to-model-the-losses-of-mosfet-with-diode?show=1298#a1298
Hello,<br />
<br />
With this particular datasheet, there is limited information available as you mentioned, and we recommend you contact the manufacturer to request additional datapoints, curves, etc. To fully diagnose the issue regarding the error message, we would need to see your model and thermal description files. This might be easily fixed with a few additional datapoints in the thermal description. It might also be that the thermal cooling network is insufficient or that you are not operating the device within its normal range.<br />
<br />
Regards,<br />
<br />
Krishttp://forum.plexim.com/1296/how-to-model-the-losses-of-mosfet-with-diode?show=1298#a1298Tue, 20 Aug 2019 17:10:12 +0000Answered: How to specify Diode resistance and Diode forward drop in thermal modelling of MOSFET with Diode?
http://forum.plexim.com/1294/specify-diode-resistance-forward-thermal-modelling-mosfet?show=1297#a1297
Hello,<br />
<br />
This component only allows you to specify the device on-resistance in the on state (conducting in either direction). To include Vf_diode, Ron_diode, or to model current sharing during reverse conduction, you will need to use separate MOSFET and diode components.<br />
<br />
Regards,<br />
<br />
Krishttp://forum.plexim.com/1294/specify-diode-resistance-forward-thermal-modelling-mosfet?show=1297#a1297Tue, 20 Aug 2019 17:04:13 +0000Answered: example of config solver parameters PLECS XML-RPC with python.
http://forum.plexim.com/1277/example-config-solver-parameters-plecs-xml-rpc-with-python?show=1288#a1288
<pre class="editorCode">opts = {'ModelVars' : { 'varL' : 50e-6 }, </pre><pre class="editorCode"> 'SolverOpts' : { 'Solver' : 'discrete',</pre><pre class="editorCode"> 'StartTime' : 0,</pre><pre class="editorCode"> 'StopTime' : 0.1</pre><pre class="editorCode"> }
}</pre>http://forum.plexim.com/1277/example-config-solver-parameters-plecs-xml-rpc-with-python?show=1288#a1288Mon, 19 Aug 2019 07:35:36 +0000Answered: Fixpoint Controller Simulation
http://forum.plexim.com/1249/fixpoint-controller-simulation?show=1270#a1270
Hi,<br />
<br />
Unfortunately only DLLs using C and C++ are officially supported in PLECS. Googling gives a few option that you could try, but again this is fully experimental and not officially supported/tested by the Plexim developers.<br />
<br />
1. Implement the fixed-point control algorithm in C using the FixMath library (<a href="http://www.nongnu.org/fixmath/doc/index.html" rel="nofollow">http://www.nongnu.org/fixmath/doc/index.html</a>)<br />
2. Embed python into C, see e.g. <a href="https://docs.python.org/2/extending/embedding.html" rel="nofollow">https://docs.python.org/2/extending/embedding.html</a> or <a href="https://www6.software.ibm.com/developerworks/education/l-pythonscript/l-pythonscript-ltr.pdf" rel="nofollow">https://www6.software.ibm.com/developerworks/education/l-pythonscript/l-pythonscript-ltr.pdf</a><br />
3. It might be possible to create a dll from Python using Cython (see <a href="https://cython.org/#about" rel="nofollow">https://cython.org/#about</a> or <a href="https://docs.python.org/3/faq/windows.html#is-a-pyd-file-the-same-as-a-dll" rel="nofollow">https://docs.python.org/3/faq/windows.html#is-a-pyd-file-the-same-as-a-dll</a>)<br />
<br />
Best regards,<br />
NFhttp://forum.plexim.com/1249/fixpoint-controller-simulation?show=1270#a1270Fri, 16 Aug 2019 15:56:59 +0000Answered: How to run script file in PLECS without using MATLAB?
http://forum.plexim.com/1261/how-to-run-script-file-in-plecs-without-using-matlab?show=1263#a1263
Hello,<br />
<br />
I assume you mean PLECS Standalone when you said you only have PLECS? But anyway, we recommend the PLECS User Manual, available on our website at www.plexim.com/download/documentation, or the built-in Online Help as a resource for many questions on using the tool. In the Initialization Parameters window of the Simulation Parameters window in PLECS Standalone you can enter any valid MATLAB/Octave expression, consisting of MATLAB/Octave functions, operators, and variables. So this can directly be a code that is run to initialize variables, or you can reference by name an m file that sits in the same directory as the model. If you want to run multiple situations or start and modify a simulation or analysis, for example, there is both an internal scripting environment in PLECS Standalone, and a method for externally controlling PLECS Standalone. Both options are described in Chapter 10 "Simulation Scripts". Please let me know if you have further questions.<br />
<br />
Regards,<br />
<br />
Krishttp://forum.plexim.com/1261/how-to-run-script-file-in-plecs-without-using-matlab?show=1263#a1263Wed, 14 Aug 2019 17:48:07 +0000Documents for designing snubber circuits for three phase thyristor bridge rectifier
http://forum.plexim.com/1258/documents-designing-snubber-circuits-thyristor-rectifier
I am looking for any help with the design of RC snubber circuit for the three phase thyristor bridge rectifier. The thryistors (SCRs) undergo reverse recovery process during turnoff and hence they experience huge voltage spikes (or overvoltages) if snubbers are not used. Are there any design procedures available in designing the RC snubber circuits for such a rectifier configuration. <br />
<br />
Thanks in advance.<br />
<br />
Malepati Sankar.http://forum.plexim.com/1258/documents-designing-snubber-circuits-thyristor-rectifierTue, 13 Aug 2019 06:58:32 +0000Answered: What is Lrr in 'Thyristor with reverse recovery'?
http://forum.plexim.com/1243/what-is-lrr-in-thyristor-with-reverse-recovery?show=1254#a1254
Hello,<br />
<br />
Please see the reference paper for this implementation, and specifically a short discussion of the inductance on Page 3: <a href="https://cds.cern.ch/record/291468/files/cn-95-016.pdf" rel="nofollow">https://cds.cern.ch/record/291468/files/cn-95-016.pdf</a><br />
<br />
Let us know if you have further questions.<br />
<br />
Regards,<br />
<br />
Krishttp://forum.plexim.com/1243/what-is-lrr-in-thyristor-with-reverse-recovery?show=1254#a1254Mon, 12 Aug 2019 16:56:02 +0000Answered: How to set the parameter of the thermal resistance Rth(or Zth) between case and heat sink?
http://forum.plexim.com/1250/parameter-the-thermal-resistance-rth-between-case-heat-sink?show=1253#a1253
Hello Sara,<br />
<br />
Yes, from the image you attached, you have implemented a viable solution for defining Rth,cs. This is not necessary, but should you want to include the thermal capacitance of the case and/or heat sink you have two options. Either you will need to design a hierarchical structure of subsystems to define the thermal layers and use the Ambient Temperature component inside to connect to the nearest external layer (e.g., device sits on Case heat sink block, and via Rth,cs connected to ambient outside of subsystem, which is actually the true heat sink of the system), or directly place a Thermal Capacitor at each node in between.<br />
<br />
Regards,<br />
<br />
Krishttp://forum.plexim.com/1250/parameter-the-thermal-resistance-rth-between-case-heat-sink?show=1253#a1253Mon, 12 Aug 2019 16:51:29 +0000Plecs blockset is not saving the data for complete simulation in .csv file?
http://forum.plexim.com/1206/plecs-blockset-not-saving-the-data-complete-simulation-file
I am using PLecs Blockset with matalb and trying to save my results in .csv file. But the file is not loading properly and does not include the data points for complete simulation. PLease help how I can extract the waveforms from scope and edit/ modify them for my use.<br />
<br />
<br />
<br />
Thanks<br />
<br />
Snehahttp://forum.plexim.com/1206/plecs-blockset-not-saving-the-data-complete-simulation-fileThu, 25 Jul 2019 15:19:13 +0000How can I get an accurate power loss information using thermal description in case of soft switching?
http://forum.plexim.com/1184/accurate-power-information-thermal-description-switching
Hi, <br />
<br />
I working on loss modelling of PFC converter. My PFC operates in boundary conduction mode (CrCM) and the MOSFET switches on at Valley or zero valley (ZVS) of drain-source voltage. In order to achieve VS/ZVS, I used a parallel capacitance (22pF from datasheet) and reverse diode (Body diode) across the MOSFET. To calculate the power loss I am using thermal model. The problem is, at the valley point (when let's say Vds = 320V) the instantaneous voltage drop across capacitor causes a big current spike (approx. 900A) through the MOSFET. Thermal model calculates conduction power loss corresponding to this current spike too which is in order of kW. Is there any way around to get an accurate power loss during soft switching? <br />
<br />
Thanks <br />
<br />
Qurathttp://forum.plexim.com/1184/accurate-power-information-thermal-description-switchingSat, 20 Jul 2019 17:51:31 +0000Implementing Fuzzy Logic Control for an Energy Storage System
http://forum.plexim.com/1178/implementing-fuzzy-logic-control-for-energy-storage-system
Hello,<br />
<br />
I need to use fuzzy logic control for a hybrid energy storage system (battery + supercapacitor) in PLECS. I see some documents how to use fuzzy logic control for MATLAB. However I do not know how to implement fuzzy logic control for PLECS.<br />
<br />
Best regards,<br />
<br />
Murathttp://forum.plexim.com/1178/implementing-fuzzy-logic-control-for-energy-storage-systemFri, 19 Jul 2019 17:45:00 +0000Answered: MOSFET with diode. conduction loss overestimated when current is negative and MOSFET turned ON.
http://forum.plexim.com/1168/mosfet-conduction-overestimated-current-negative-mosfet?show=1169#a1169
Hello,<br />
<br />
This is a great question. If you use separate MOSFET and diode components, the current sharing (and therefore the losses) during reverse conduction of the overall device is determined by the path impedances of the MOSFET and body diode. If you have chosen not to provide on-resistance values for either device, the current will be shared equally between the diode and MOSFET.<br />
<br />
You should consider the typical timing of the switching events. Can it be assumed that the diode conducts for only a small time during the interval before the FET is gated on? Are you expecting a specific current sharing behavior if the FET is reverse-biased? Or do you want PLECS to only consider the Rds(on) characteristic in this situation? <br />
<br />
If you want the MOSFET to carry the entire current when it is gated on during third quadrant conduction, you can actually use the combined MOSFET and Diode component. I have attached a working example of this approach, which requires a little bit of explanation. The single thermal description uses Custom Tables that are called in the Conduction Loss tab's formula and are chosen based on whether the MOSFET gate signal is zero or nonzero. To easily view the example device thermal description, with this model open, go to the Window>Thermal Library Browser menu option and look for "MOSFET3rdQ_body_diode".<br />
<br />
You should also look under the mask of the MOSFET converter and see that it looks as it normally does, but in fact, each device is reimplemented as it’s own masked subsystem. Looking further under the mask of one device you will see that a gate signal tag has been added, which is used in the conduction loss equations. You will see that at each subsystem level’s mask we are passing the gate signal by reference to the next higher level. Please let me know if you have questions, but I believe this implementation can be easily replicated and modified to include your own part’s loss data.<br />
<br />
Regards,<br />
<br />
Krishttp://forum.plexim.com/1168/mosfet-conduction-overestimated-current-negative-mosfet?show=1169#a1169Thu, 18 Jul 2019 22:11:42 +0000Answered: How to simulate a device with known V-I Equation
http://forum.plexim.com/1142/how-to-simulate-a-device-with-known-v-i-equation?show=1160#a1160
Hello,<br />
<br />
Due to the fact that the voltage applied to the device affects the current, and the current driven through it affects the voltage drop across it, a variable-resistance by it's very nature creates an algebraic loop. This is not easily solved without taking certain steps to break such a loop. We introduced "Algebraic Components" into the PLECS library (Electrical and Mechanical components) in a recent release that can be used for exactly this type of problem. I have included a very basic model showing the design and operation of a MOV using a current source stimulus and some dummy IV curve data implemented in a 1D Lookup Table. The requirement of the Algebraic Component is that the two output signals, "v" and "i", must affect the input signal "0" by means of a direct feedthrough path. In this case, I chose to drive the "0" input signal to zero by subtracting the calculated value of voltage as provided by the lookup table from the measured voltage value in the component. You should be able to use this model as a reference and include your own custom data in the lookup table (you could also have temperature dependence via a 2D Lookup Table). I hope this helps.<br />
<br />
Regards,<br />
<br />
Krishttp://forum.plexim.com/1142/how-to-simulate-a-device-with-known-v-i-equation?show=1160#a1160Wed, 17 Jul 2019 19:03:05 +0000Answered: Charging using CCCV with a buck converter
http://forum.plexim.com/915/charging-using-cccv-with-a-buck-converter?show=1136#a1136
Hi the problem is in your control<br />
<br />
you are working CC with 20A until 49.5V and the CV, the problem is that there is a current jump to 360A that cause a big voltage drop in the battery model (actually is the internal voltage drop is higher than the external voltage drop)<br />
<br />
You should release the CC lately or correct the string battery parameters.http://forum.plexim.com/915/charging-using-cccv-with-a-buck-converter?show=1136#a1136Wed, 10 Jul 2019 10:23:16 +0000Answered: transfer function problem (AC sweep analysis)
http://forum.plexim.com/1129/transfer-function-problem-ac-sweep-analysis?show=1133#a1133
<p>PLECS is running into numerical truncation problems due to your choice of parameters:</p><ul><li>large DC offset, i.e. your filter input (1330)</li><li>large time constant (2000)</li><li>very small "Rel. perturbation for Jacobian" in the "Steady-State Options" of the AC Sweep (1e-6)</li></ul><p>As a consequence, when PLECS tries to linearize the model, it gets a plain 0 for the Jacobian matrix.</p><p>If you increase the "Rel. perturbation for Jacobian" to 1e-4 (which is the default), you will get the expected result. But if you then <em>also</em> increase the filter input or the time constant by a factor of 100, you will run into the same problem again. </p>http://forum.plexim.com/1129/transfer-function-problem-ac-sweep-analysis?show=1133#a1133Wed, 10 Jul 2019 09:18:19 +0000Answered: Matlab 2013b crashes after installing PLECS
http://forum.plexim.com/1128/matlab-2013b-crashes-after-installing-plecs?show=1131#a1131
<p class="editorCode">This is due to a bug in MATLAB R2013b: MATLAB freezes when opened if it executes a "startup.m" file that adds an "info.xml" file to the search path.</p><p class="editorCode">For a detailed explanation and possible solutions, please see this <a rel="nofollow" href="https://www.plexim.com/support/solutions/1027">technical solution</a> on the Plexim web site.</p>http://forum.plexim.com/1128/matlab-2013b-crashes-after-installing-plecs?show=1131#a1131Wed, 10 Jul 2019 06:51:41 +0000