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Powered by Question2AnswerAnswered: 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 +0000Answered: Small signal analysis for 3-phase inverter
http://forum.plexim.com/37/small-signal-analysis-for-3-phase-inverter?show=1117#a1117
<p>Hi <a rel="nofollow" href="https://forum.plexim.com/user/yunpeng">yunpeng</a> generally for inverter, they are normally buck converter and you are not using contolling theory like DCDC but more like LC filter damping. I think all the answer you need are in this cookbook:</p><p><a rel="nofollow" href="https://www.amazon.com/Digital-Control-Electronics-Synthesis-Lectures/dp/1627057536">https://www.amazon.com/Digital-Control-Electronics-Synthesis-Lectures/dp/1627057536</a></p><p> </p>http://forum.plexim.com/37/small-signal-analysis-for-3-phase-inverter?show=1117#a1117Fri, 05 Jul 2019 09:03:02 +0000Answered: Interfacing Xilinx Zedboard or Kintex 7 (FPGA) with PLECS RT Box for HIL test
http://forum.plexim.com/1070/interfacing-xilinx-zedboard-kintex-fpga-with-plecs-box-test?show=1110#a1110
Hello,<br />
<br />
Plexim offers the Interface Boards listed on our website: <a href="https://www.plexim.com/products/rt_box" rel="nofollow">https://www.plexim.com/products/rt_box</a>. This list does not currently include an interface to an FPGA board.<br />
<br />
Best regards,<br />
<br />
Krishttp://forum.plexim.com/1070/interfacing-xilinx-zedboard-kintex-fpga-with-plecs-box-test?show=1110#a1110Tue, 02 Jul 2019 17:57:49 +0000Using CAN on the RT Box 1
http://forum.plexim.com/1082/using-can-on-the-rt-box-1
Hi,<br />
<br />
<br />
<br />
I'm trying to make use of the CAN interface on the RT using the digital breakout board.<br />
<br />
As soon as I check the CAN1 in the Coder options I get an error saying:<br />
<br />
"Target response 401, Error transfering <a href="http://169.xxx.x.xxx/cgi-bin/start.cgi" rel="nofollow">http://169.xxx.x.xxx/cgi-bin/start.cgi</a> - server replied: Internal Server Error<br />
<br />
Communication with realtime simulation failed."<br />
<br />
when I start the build process. This happens with an empty PLECS model and with and without any connection to the D-Sub connectors.<br />
<br />
Same happens when using the CAN Transmitter from PLECS standalone.<br />
<br />
I have also monitored the CAN interface using a CAN-2-USB adapter and did not see any sort of communication by the RT box.<br />
<br />
See attached a screenshot of the whole setup.<br />
<br />
<br />
<br />
Best regards<br />
<br />
gntjahttp://forum.plexim.com/1082/using-can-on-the-rt-box-1Wed, 26 Jun 2019 08:28:35 +0000Answered: How can be computed the switching frequency?
http://forum.plexim.com/1014/how-can-be-computed-the-switching-frequency?show=1069#a1069
<p>try this one I have try to build a F-V converter, otherwise the best is a state machine block<img alt="" src="http://forum.plexim.com/?qa=blob&qa_blobid=8271784498626906327" style="height:469px; width:600px"></p>http://forum.plexim.com/1014/how-can-be-computed-the-switching-frequency?show=1069#a1069Fri, 21 Jun 2019 07:45:04 +0000Answered: How to simulate a three phase transformer with mutual inductance?
http://forum.plexim.com/932/how-simulate-three-phase-transformer-with-mutual-inductance?show=1068#a1068
<p><img alt="" src="http://forum.plexim.com/?qa=blob&qa_blobid=4845976476547182391" style="height:447px; width:513px"></p><p> </p><p>Is this something useful for you? this is the Yy transformer when you look in the block</p>http://forum.plexim.com/932/how-simulate-three-phase-transformer-with-mutual-inductance?show=1068#a1068Fri, 21 Jun 2019 06:36:05 +0000Answered: Parse a PLECS file
http://forum.plexim.com/1017/parse-a-plecs-file?show=1065#a1065
Hi<br />
<br />
Im doing one to read out the parameter of initialization and use it to create a class in python for my model. what you need exactly? Otherwise I agree with oliver that is better to use the API<br />
<br />
Another useful way to use directly the change of code is adding complex probe content, like 20-30 probe signals that have the same name, but maybe is only my need :)http://forum.plexim.com/1017/parse-a-plecs-file?show=1065#a1065Fri, 21 Jun 2019 06:31:24 +0000Scope GetCursorData through XMLRPC
http://forum.plexim.com/1060/scope-getcursordata-through-xmlrpc
<p>My question is similar in spirit to:</p><p><a rel="nofollow" href="https://forum.plexim.com/673/exporting-scope-data-as-csv-using-xml-rpc?show=673#q673">https://forum.plexim.com/673/exporting-scope-data-as-csv-using-xml-rpc?show=673#q673</a></p><p>where the user wanted to use the plecs('scope', 'scopepath', 'ExportCSV', 'filename') plecs to export some scope data to CSV using python's xml rpc client.</p><p>I would like to use plecs('scope', 'scopepath', 'getcursordata', [t1, t2], 'analysis1, ...) from xmlrpc but server.plecs.scope('scopepath', 'GetCursorData', [t1, t2], 'analysis1', ... ) returns an "invalid method parameters" error. My guess is that this is another function which does not translate to xml-rpc? If that is the case is there any plan to port these "missing" functions from plecs standalone script environment to xml-rpc?</p>http://forum.plexim.com/1060/scope-getcursordata-through-xmlrpcWed, 19 Jun 2019 18:19:33 +0000Answered: Interleaving connections
http://forum.plexim.com/1024/interleaving-connections?show=1032#a1032
<p>Hi Goutham,</p><p>As given in the PLECS Help Viewer under "Connections", for drawing a branch from an existing connection, place the mouse pointer where it is desired that the branch will start. With the right mouse button or with the left mouse button while holding down the [Ctrl] key (or [command] key on Mac OS), create a branch to a new destination by dragging the crosshairs.</p><p>I'm also attaching the "PLECS Cheat Sheet" here for other PLECS shortcuts.</p><p>A solid black dot marks a connection between two wires. Two electrical wires merely overlapping on one another without a connection will not have this solid black dot, therefore a curved wire, as shown in your circuit, to mark this distinction, isn't necessary. </p><p>An example of an interleaved boost converter is given in the PLECS demo model library. Browse to Window > Demo Models, and search for "Single-Phase Battery Charger". Open the PLECS model and then double click on the AC/DC subsystem to view the attached schematic.</p><p><img alt="" src="http://forum.plexim.com/?qa=blob&qa_blobid=8852781333049902338" style="height:371px; width:600px"></p><p>Best regards,<br>Manu</p><p> </p>http://forum.plexim.com/1024/interleaving-connections?show=1032#a1032Wed, 12 Jun 2019 19:24:52 +0000Answered: How much is the loss erro introduced for not considering the diode reverse recovery behavior in the thermal simulation?
http://forum.plexim.com/992/introduced-considering-reverse-recovery-behavior-simulation?show=1008#a1008
it depend strongly from the diode you use, power diode have different effect depending from the temperature, for "normal" diode the temperature variation of the reverse recovery is also a factor 100%. <br />
<br />
But I think this will not be the main cause of efficiency degradation in your power train, that means in first approximation is negligible.http://forum.plexim.com/992/introduced-considering-reverse-recovery-behavior-simulation?show=1008#a1008Thu, 06 Jun 2019 08:36:18 +0000Answered: How do I make this system run faster.
http://forum.plexim.com/977/how-do-i-make-this-system-run-faster?show=994#a994
<p>My 2 Cents:</p><ul><li>Please clean up your PLECS schematic before you submit it to get help. It increases the chance to get a quick answer. </li><li>I suspect the circuit is getting stuck in some kind of algebraic loop. (Not an expert on that.)</li><li>Why does the voltage controller have output saturation and the current controller doesn't? You always want to add output saturation.</li><li>The combination of the current reference from the voltage controller and the set current is usually done using a MIN(a,b) function in unidirectional converters, not sure what your goal is with the switch. For bidirectional converters it might however get more convoluted. </li><li>Applying those two changes worked for me.</li><li>If you plan to operate the PI controller in constant saturation, you need to think about adding an integrator anti wind-up scheme. </li></ul><p>Hope this helped.</p><p>Falk</p><p> </p>http://forum.plexim.com/977/how-do-i-make-this-system-run-faster?show=994#a994Tue, 04 Jun 2019 15:26:18 +0000Answered: How to add the Manufacture models to PLECS Library
http://forum.plexim.com/981/how-to-add-the-manufacture-models-to-plecs-library?show=982#a982
Hello,<br />
<br />
Did you add the folder containing the .xml files to the list of "Thermal description search paths" in the "Thermal" tab of the PLECS Preferences window? Note that this is not the same as the "User libraries" list in the "Libraries" tab, which is used for creating custom components.<br />
<br />
Best regards,<br />
<br />
Krishttp://forum.plexim.com/981/how-to-add-the-manufacture-models-to-plecs-library?show=982#a982Fri, 31 May 2019 22:58:57 +0000Answered: PLECS IGBT Power Losses
http://forum.plexim.com/971/plecs-igbt-power-losses?show=973#a973
Hello,<br />
<br />
It sounds like you need to do some homework on how thermal losses work, but do you have a device or data sheet you can reference? Many of the devices currently supported with PLECS loss and thermal models are listed here: <a href="https://www.plexim.com/plecs/thermal" rel="nofollow">https://www.plexim.com/plecs/thermal</a><br />
<br />
Regards,<br />
<br />
Krishttp://forum.plexim.com/971/plecs-igbt-power-losses?show=973#a973Wed, 29 May 2019 04:17:59 +0000Answered: How to enter thermal impedance of IGBT and Diode separately in the thermal model of 'IGBT with Diode'?
http://forum.plexim.com/969/enter-thermal-impedance-diode-separately-thermal-model-diode?show=972#a972
Hello,<br />
<br />
In this case you should use separate IGBT and diode components.<br />
<br />
Regards,<br />
<br />
Krishttp://forum.plexim.com/969/enter-thermal-impedance-diode-separately-thermal-model-diode?show=972#a972Wed, 29 May 2019 04:15:55 +0000Answered: dismiss last username and change user to work with plecs software
http://forum.plexim.com/960/dismiss-last-username-change-user-work-with-plecs-software?show=961#a961
Hello,<br />
<br />
Yes, exactly.<br />
<br />
Thank you,<br />
<br />
Krishttp://forum.plexim.com/960/dismiss-last-username-change-user-work-with-plecs-software?show=961#a961Thu, 23 May 2019 14:19:50 +0000Answered: Heat Sink Simulation Error
http://forum.plexim.com/927/heat-sink-simulation-error?show=958#a958
Hello, you just need to provide a gate resistance value, e.g. 2.5 ohms.http://forum.plexim.com/927/heat-sink-simulation-error?show=958#a958Tue, 21 May 2019 17:08:52 +0000Answered: Why my simulation shows inconsistent source, state/source dependence ?
http://forum.plexim.com/942/simulation-shows-inconsistent-source-state-source-dependence?show=945#a945
Hi Manoj, <br />
<br />
The current source needs a valid return path at all times, which is not given in your circuit. <br />
<br />
The PLECS documentation states: "A current source may not be open-circuited or connected in series to an inductor or any other current source."<br />
<br />
Hope this helps.<br />
<br />
Falkhttp://forum.plexim.com/942/simulation-shows-inconsistent-source-state-source-dependence?show=945#a945Thu, 16 May 2019 08:06:49 +0000Answered: Can we use dynamic variables to represent a numerator/denominator coefficients in transfer function block ?
http://forum.plexim.com/920/variables-represent-numerator-denominator-coefficients?show=926#a926
<p>Hi Dilan,</p><p>You cannot update a variable, for example "w01" in your case, within the simulation, however you can create a dynamic transfer function by expanding it as shown in the "Help" section (see the image below) and then feeding a value calculated from the simulation to this expanded transfer function.</p><p><img alt="" src="http://forum.plexim.com/?qa=blob&qa_blobid=3628199152626546579" style="height:458px; width:600px"></p><p>I have created the attached model (both Standalone and Blockset versions) for the transfer function you described. (<strong>Note that t</strong>his model contains model initialization commands that are accessible from:<br><em>PLECSStandalone: </em>The menu <strong>Simulation+SimulationParameters...+Initializations </strong><br><em>PLECS Blockset: </em>The Simulink menu <strong>File + Model Properties + Callbacks + InitFcn*</strong>)</p><p><img alt="" src="http://forum.plexim.com/?qa=blob&qa_blobid=15067648052012871850" style="height:75px; width:232px"></p><p>By comparing this equation with the equation from the "Help" section, we get the following numerator and denominator coefficients</p><p>n2 =0;<br>n1=6282;<br>n0=0;<br>d2=1;<br>d1=6282;<br>d0=w01;</p><p>From these values, we can calculate the coefficients for the expanded transfer function (modeled in the "dynamic transfer fcn" subsystem) as follows:</p><p>b2=1/d2;<br>b1=d1/d2;<br>b0=d0/d2;<br>a2=n2;<br>a1=n1-n2*b1;<br>a0=n0-n2*b0;</p><p>In your case, since your "d0" is a variable obtained from the simulation, we need to calculate the coefficients "a0" and "b0" from the simulation as well. We can achieve this by replacing the "Gain" blocks corresponding to "a0" and "b0" with "Product" blocks and then calculating their values from the simulation using a "function" component. In the attached model, the "variable" port corresponds to the measured frequency, "w01".<br><br><img alt="" src="http://forum.plexim.com/?qa=blob&qa_blobid=5049549421702339840" style="height:325px; width:600px"></p><p>This model can also be adapted to work with any other second order transfer function by changing the numerator and denominator coefficients under initialization parameters, as well as replacing the corresponding gain blocks in the "dynamic transfer fcn" subsystem with a product block combined with a "function" component, to accept the desired variable from the simulation, as shown above.</p><p>Regards,<br>Manu</p><p> </p>http://forum.plexim.com/920/variables-represent-numerator-denominator-coefficients?show=926#a926Fri, 10 May 2019 20:05:34 +0000Does anyone have experiences in MPPT schematics for wind turbines PMSG in PLECS?
http://forum.plexim.com/913/does-anyone-have-experiences-mppt-schematics-turbines-plecs
http://forum.plexim.com/913/does-anyone-have-experiences-mppt-schematics-turbines-plecsTue, 07 May 2019 11:22:29 +0000CCCV for a buck converter charging a lithium ion battery model
http://forum.plexim.com/905/cccv-for-buck-converter-charging-lithium-ion-battery-model
Hi,<br />
<br />
I am trying to charge the battery using cccv; however, the current seems to not drop once cv is enabled and the voltage increases more than 50V. Any suggestions of how to fix that?http://forum.plexim.com/905/cccv-for-buck-converter-charging-lithium-ion-battery-modelFri, 03 May 2019 17:42:45 +0000Snubber capacitance for IGBT error
http://forum.plexim.com/892/snubber-capacitance-for-igbt-error
<p> </p><p>I want to simulate the Snubber capacitance at both ends of IGBT to get its optimal effect on improving the switching loss efficiency of the system, but there are various errors.like Matrix is singular. Does anyone know how to solve them?</p><p><img alt="" src="http://forum.plexim.com/?qa=blob&qa_blobid=1981077171757521675" style="height:155px; width:600px"></p>http://forum.plexim.com/892/snubber-capacitance-for-igbt-errorTue, 30 Apr 2019 08:59:17 +0000Answered: Change color of mouse pointer in scope
http://forum.plexim.com/530/change-color-of-mouse-pointer-in-scope?show=885#a885
You can easily change it by changing the settings of mouse pointer.http://forum.plexim.com/530/change-color-of-mouse-pointer-in-scope?show=885#a885Sat, 27 Apr 2019 06:58:51 +0000Answered: Run multiple simulations in parallel using XML-RPC
http://forum.plexim.com/874/run-multiple-simulations-in-parallel-using-xml-rpc?show=875#a875
Hello,<br />
<br />
Unfortunately this is not possible currently.<br />
<br />
Thank you,<br />
<br />
Krishttp://forum.plexim.com/874/run-multiple-simulations-in-parallel-using-xml-rpc?show=875#a875Tue, 23 Apr 2019 15:57:06 +0000Answered: how can i calculate switching losses and efficiency?
http://forum.plexim.com/869/how-can-i-calculate-switching-losses-and-efficiency?show=870#a870
Hello,<br />
<br />
Should you have specific questions, please post them here, but a good example model to show how you can measure and calculate switching losses and efficiency (in a Scope plot, or displaying a magnitude in digits) is the PLECS demo model called "Buck Converter with Thermal Model". Please review this model and description.<br />
<br />
Best regards,<br />
<br />
Krishttp://forum.plexim.com/869/how-can-i-calculate-switching-losses-and-efficiency?show=870#a870Thu, 18 Apr 2019 16:10:35 +0000Answered: Different scope time range
http://forum.plexim.com/860/different-scope-time-range?show=865#a865
I just tried the custom time range in the Scope Parameters Window. It only allows you to set the end time as far as i can tell.<br />
<br />
I would suggest to use the Save View function.http://forum.plexim.com/860/different-scope-time-range?show=865#a865Wed, 17 Apr 2019 06:27:44 +0000Answered: simulation examples
http://forum.plexim.com/862/simulation-examples?show=864#a864
<p>Hello,</p><p>From the <em>Window</em> menu inside PLECS Standalone you can access the "Demo Models". In PLECS Blockset, I recommend you type 'plecslib' into the MATLAB command line, and from the PLECS library window that opens, there is a "Demos" block (see time 4:00 in <a rel="nofollow" href="https://www.plexim.com/support/videos/installing-blockset-win">this video</a>).</p><p>These models are then listed under the "Power Supplies" category. You can also search for a topology from within the PLECS Documentation built-in.</p><p>Regards,</p><p>Kris</p>http://forum.plexim.com/862/simulation-examples?show=864#a864Tue, 16 Apr 2019 16:16:11 +0000Answered: How to calculate the magnetic resistance for the transformer simulation in the Plecs Magnetic Domain?
http://forum.plexim.com/845/calculate-magnetic-resistance-transformer-simulation-magnetic?show=858#a858
Hello,<br />
<br />
Here is a great resource from our colleague at Plexim's PhD research: <a href="https://infoscience.epfl.ch/record/253555/files/2018_APEC_Luo.pdf" rel="nofollow">https://infoscience.epfl.ch/record/253555/files/2018_APEC_Luo.pdf</a> Inside you will find the calculation of the resistance value for a transformer laminate.<br />
<br />
Best regards,<br />
<br />
Krishttp://forum.plexim.com/845/calculate-magnetic-resistance-transformer-simulation-magnetic?show=858#a858Thu, 11 Apr 2019 16:17:23 +0000Answered: From Matlab function to C-script block
http://forum.plexim.com/850/from-matlab-function-to-c-script-block?show=855#a855
Hello,<br />
<br />
The PLECS C-Script block can be used to link to C library files or you can manually port the code from your embedded files into the appropriate functions, but in both cases, this may be cumbersome. You might consider to generate a DLL block that represents your logic, or the State Machine block, which is a bit more visually intuitive to work with than the C-Script block.<br />
<br />
But looking at your .m file, you might just want to include this code as is (or with slight modifications) in the initialization commands of a subsystem. Out of curiosity, why are you trying to port it from MATLAB code to C code?<br />
<br />
Regards,<br />
<br />
Krishttp://forum.plexim.com/850/from-matlab-function-to-c-script-block?show=855#a855Wed, 10 Apr 2019 17:57:00 +0000Answered: Speed up simulation by building the whole model in plecs?
http://forum.plexim.com/841/speed-up-simulation-by-building-the-whole-model-in-plecs?show=854#a854
Hello Junwei,<br />
<br />
Unfortunately there is not a one size fits all answer to this question, but it is certainly our recommendation to PLECS Blockset users to place as much of a model as possible inside the PLECS Circuit block in Simulink, and this has been shown to generally increase the simulation speed. More likely though, there are certain blocks or schemes in the Simulink portion of your model that may not be optimized, or are more efficiently done on the PLECS side. So we can't say for certain, but the model porting may be worth your effort. We can also provide feedback on your model in general, and possibly optimize its speed in its current form, if you send it to support@plexim.com. <br />
<br />
Best regards,<br />
<br />
Krishttp://forum.plexim.com/841/speed-up-simulation-by-building-the-whole-model-in-plecs?show=854#a854Wed, 10 Apr 2019 17:45:45 +0000Answered: Variable parameters for blocks during simulation in PLECS standalone
http://forum.plexim.com/847/variable-parameters-blocks-during-simulation-standalone?show=851#a851
<p>The initialization commands are executed prior to the simulation and you can not change parameters from there once the simulation is running. </p><p>Not sure what the best solution is. I have used the state machine block to generate PWM signals in the past like this (f, d are inputs to the state machine):</p><p><img alt="" src="http://forum.plexim.com/?qa=blob&qa_blobid=17777840740021591557" style="height:257px; width:400px"></p>http://forum.plexim.com/847/variable-parameters-blocks-during-simulation-standalone?show=851#a851Wed, 10 Apr 2019 06:14:48 +0000Answered: Losses in MMC
http://forum.plexim.com/824/losses-in-mmc?show=837#a837
Hello,<br />
<br />
Currently this model uses both Power Module blocks with a Sub-Cycle Average implementation for AC side I, and Averaged models for AC side II. In order to do loss modeling, you will need to replace the power semiconductors in that model with our standard IGBT/Diodes components from our library. Have you looked at any of our demo models that use the thermal modeling features of PLECS? There are none currently for multilevel converters, but you can certainly build this. How many power levels are you looking for?<br />
<br />
Thanks,<br />
<br />
Krishttp://forum.plexim.com/824/losses-in-mmc?show=837#a837Fri, 29 Mar 2019 22:00:23 +0000Answered: DC DC bidirectional converter
http://forum.plexim.com/829/dc-dc-bidirectional-converter?show=833#a833
Your model is quite convoluted, not sure what the problem is. I don't think you need two controllers to start with. You can add those if you need different performance for charge / discharge. Also, I would suggest to use MOSFETs in a totem-pole configuration instead of IGBTs.<br />
<br />
Your problem can be solved way simpler. See attached minimum working model.<br />
<br />
Cheers<br />
<br />
Falkhttp://forum.plexim.com/829/dc-dc-bidirectional-converter?show=833#a833Wed, 27 Mar 2019 17:01:24 +0000Answered: Intrinsic one sample delay in triggered subsystem?
http://forum.plexim.com/816/intrinsic-one-sample-delay-in-triggered-subsystem?show=828#a828
Hi,<br />
<br />
computation time is not modelled intrinsically in PLECS. Any mathematical operation in a simulation step is instantanious, e.g. the output of a sine block becomes the sine of its input in the same simulation step.<br />
<br />
A triggered subsystem behaves exactly the same - it may just not be executed in every simulation step.<br />
<br />
If you want to model the delay introduced by real systems (e.g. a computation delay) you should use a delay block.<br />
<br />
As an alternative (if the computational delay is very small compared to the trigger period) you could use a Pulse Delay block behind the triggered subsystem.<br />
<br />
Kind regards,<br />
<br />
Oliver Schwartzhttp://forum.plexim.com/816/intrinsic-one-sample-delay-in-triggered-subsystem?show=828#a828Fri, 22 Mar 2019 13:27:16 +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=827#a827
Hi,<br />
<br />
In a transient simulation the results of the next time step depend on the results of the current time step. Such a simulation is therefore not well suited for parallel computation.<br />
<br />
As a result, the (single thread) speed of your CPU has the biggest impact on simulation time. PLECS profits from multi-core CPUs because it can offload things like scope rendering to another core (or run multiple simulations in parallel on different cores). The performance of your graphics card, however, has no impact on the simulation speed.<br />
<br />
Kind regards,<br />
<br />
Oliver Schwartzhttp://forum.plexim.com/819/are-there-other-ways-to-speed-up-the-simulation?show=827#a827Fri, 22 Mar 2019 13:14:09 +0000Answered: how to define trigger and condition in state machine
http://forum.plexim.com/825/how-to-define-trigger-and-condition-in-state-machine?show=826#a826
Hi Shaofei,<br />
<br />
Have a look at the "Buck Converter with Constant On-Time Control, State Machine" demo model, it will answer your question.<br />
<br />
Cheers<br />
<br />
Falkhttp://forum.plexim.com/825/how-to-define-trigger-and-condition-in-state-machine?show=826#a826Fri, 22 Mar 2019 12:03:51 +0000Answered: Design Notch Filter
http://forum.plexim.com/813/design-notch-filter?show=818#a818
Looks like the transfer function in the attachment is incorrectly printed.<br />
<br />
I would expect that the notch filter also has a pair of complex-conjugate poles, i.e.:<br />
<br />
N(s) = (s^2+wn^2)/(s^2+2*wn/Q*s+wn^2)http://forum.plexim.com/813/design-notch-filter?show=818#a818Wed, 13 Mar 2019 18:19:18 +0000High frequency noise in multitone analysis
http://forum.plexim.com/817/high-frequency-noise-in-multitone-analysis
Hi, I am getting the correct response for multitone analysis in the low to mid-frequency range. However, in the high frequency range, the response is very noisy expecially for the phase response. I have read the user guide and I have implemented proper steps. The fact that I am getting a correct response in the low to mid frequency and the high frequency makes me think that I implemented the analysis correctly, but perhaps I am missing some sort of adjustments related to responses in the high frequency range.<br />
<br />
Thanks!http://forum.plexim.com/817/high-frequency-noise-in-multitone-analysisWed, 13 Mar 2019 18:01:26 +0000Answered: Using properly the Analysis Tool
http://forum.plexim.com/807/using-properly-the-analysis-tool?show=811#a811
<p>Quick Notes:</p><ul><li>The bode plot is only meaningful to fs/2 in switching converters (sampled systems)</li><li>Using 1000 points sounds excessive to me. Might only be feasible in the impulse response analysis.</li><li>Try starting with a smaller model.</li></ul><div>The "Buck Converter with Analysis Tools" demo model is a good starting point. </div><div>See attached model, where I modified the demo model.</div>http://forum.plexim.com/807/using-properly-the-analysis-tool?show=811#a811Wed, 13 Mar 2019 08:01:27 +0000Answered: how to export just the last waveform periods by scripting?
http://forum.plexim.com/773/how-to-export-just-the-last-waveform-periods-by-scripting?show=805#a805
Hello,<br />
<br />
I don't fully understand the question as it appears that you are successfully exporting the data, starting only after a pre-specified period of time using a triggered subsystem. Are you expecting something different? I have attached a modified version of the demo model your refer to that shows the same method to do this.<br />
<br />
Best regards,<br />
<br />
Krishttp://forum.plexim.com/773/how-to-export-just-the-last-waveform-periods-by-scripting?show=805#a805Mon, 11 Mar 2019 22:32:13 +0000No specific error message for algebraic loop with C-script
http://forum.plexim.com/800/no-specific-error-message-for-algebraic-loop-with-c-script
I want to model a varistor using the functional description given by the manufacturer Littelfuse for PSPICE. The characteristic of the Varistor is modeled as a power function combined with a linear behavior around current zero. I use a variable voltage source which is controlled by the current through itself. It is clear that that is an algebraic loop, but the error message that I get don't show me where the problem is in detail.http://forum.plexim.com/800/no-specific-error-message-for-algebraic-loop-with-c-scriptFri, 08 Mar 2019 12:05:50 +0000How to get phase shift from PWM out in offline simulation
http://forum.plexim.com/799/how-to-get-phase-shift-from-pwm-out-in-offline-simulation
Hello!<br />
<br />
I have a question about simulation with the utilization of the PWM out blocks to simulate the variable phase shift signal. I want to change the phase shift with a sinusoidal waveform, with RT box system everything is good, but when I am trying to simulate this in offline mode just in plecs in result I get only one phase shift. <br />
<br />
The model included. <br />
<br />
How to fix this issue?http://forum.plexim.com/799/how-to-get-phase-shift-from-pwm-out-in-offline-simulationThu, 07 Mar 2019 18:47:39 +0000Answered: Fortescue Transformation
http://forum.plexim.com/782/fortescue-transformation?show=794#a794
You will have to expand the matrix multiplication on a row-by-row basis. This can be implemented via Function blocks or, for more complex computations, in a C-Script block. Please take a look at how the Transformation blocks are implemented in the PLECS Control library (Subsystem -> Look under mask).http://forum.plexim.com/782/fortescue-transformation?show=794#a794Wed, 06 Mar 2019 13:56:02 +0000Answered: High frequency spacevector PWM output, on the RT-Box
http://forum.plexim.com/789/high-frequency-spacevector-pwm-output-on-the-rt-box?show=793#a793
For reasonable results you still have to use the PWM blocks. We are currently working on an adapted space vector modulation block for the RT Box, but it is still work in progress. Please contact support@plexim.com directly so we can see if we have a solution for your application.<br />
<br />
Kind regards,<br />
<br />
Oliver Schwartzhttp://forum.plexim.com/789/high-frequency-spacevector-pwm-output-on-the-rt-box?show=793#a793Wed, 06 Mar 2019 08:59:59 +0000Why single phase AC output current is sinusoidal with a DC shift?
http://forum.plexim.com/784/why-single-phase-ac-output-current-is-sinusoidal-with-shift
Hi All<br />
<br />
I am facing an issue with current source based converter circuit, Figure attached. The output load is single phase AC (240 V, 4 KW).<br />
<br />
I am not getting a sinusoidal output current as expected, i.e. a sine wave varying with reference as zero, instead I am getting it with a DC offset.<br />
<br />
My pulse control and other seems to be working fine, as when i replace the output with A DC source, I get the desired outputs. It's with AC that the output current is not sinusoidal.<br />
<br />
Am I missing grounding the circuit properly or anything like that? Any help would be appreciated.<br />
<br />
Thanks<br />
Sneha Thakurhttp://forum.plexim.com/784/why-single-phase-ac-output-current-is-sinusoidal-with-shiftTue, 05 Mar 2019 00:13:08 +0000Answered: Non Ideal MOSFET modelling
http://forum.plexim.com/587/non-ideal-mosfet-modelling?show=781#a781
hi the most reliable way is to measure it with a double pulse tester like the one describe here:<br />
<br />
<a href="https://www.wolfspeed.com/downloads/dl/file/id/150/product/0/sic_mosfet_double_pulse_fixture.pdf" rel="nofollow">https://www.wolfspeed.com/downloads/dl/file/id/150/product/0/sic_mosfet_double_pulse_fixture.pdf</a><br />
<br />
and then plug in PLECS the switching losses tablehttp://forum.plexim.com/587/non-ideal-mosfet-modelling?show=781#a781Mon, 04 Mar 2019 09:16:47 +0000Answered: How to select theremal resistance Rth ?
http://forum.plexim.com/632/how-to-select-theremal-resistance-rth?show=780#a780
Hi these app notes are a good starting point<br />
<br />
<a href="http://www.ti.com/lit/an/spra953c/spra953c.pdf" rel="nofollow">http://www.ti.com/lit/an/spra953c/spra953c.pdf</a> <br />
<br />
<a href="http://www.ti.com/lit/an/snva419c/snva419c.pdf" rel="nofollow">http://www.ti.com/lit/an/snva419c/snva419c.pdf</a>http://forum.plexim.com/632/how-to-select-theremal-resistance-rth?show=780#a780Mon, 04 Mar 2019 09:11:16 +0000Answered: I have conflict between THD from the scope and from normal calculation for the following signal
http://forum.plexim.com/738/conflict-between-scope-normal-calculation-following-signal?show=779#a779
<p> <em>is it possible to get THD greater than 100%?</em></p><p>Yes, it is.</p><p>As explained <a rel="nofollow" href="https://forum.plexim.com/529/what-method-calculating-plecs-does-value-plecs-look-like-right">here</a> already, the THD is calculated as sqrt(sum(V<sub>n</sub>^2))/V<sub>1</sub> for n>=2. This ratio can have any value, because V<sub>n</sub> and V<sub>1</sub> are totally independent from each other.</p><p>A better analysis of your data is only possible if you post your model. Mathematical deductions based on partial screenshots are hard to do.</p><p>Kind regards,</p><p>Oliver Schwartz</p><p> </p>http://forum.plexim.com/738/conflict-between-scope-normal-calculation-following-signal?show=779#a779Mon, 04 Mar 2019 06:34:45 +0000