# \#solver **URL:** https://forum.plexim.com/tag/solver/49.md [Latest](https://forum.plexim.com/latest.md) · [Categories](https://forum.plexim.com/categories.md) · [Tags](https://forum.plexim.com/tags.md) --- ## [How to call IPOPT Optimiser built with CasADi in PLECS?](https://forum.plexim.com/t/how-to-call-ipopt-optimiser-built-with-casadi-in-plecs/2600)
**Author:** [@pravin](https://forum.plexim.com/u/pravin)\ **Replies:** 0\ **Last updated:** [September 30, 2025, 12:13pm UTC](https://forum.plexim.com/t/how-to-call-ipopt-optimiser-built-with-casadi-in-plecs/2600 "2025-09-30T12:13:43Z")
I am trying to run some optimisation routine. I have a working version of optimiser wrapped in a function. It takes in a vector of 6 rows as input arguments and spits out a vector of 3 rows. The optimiser is built with … --- ## [MMC Cyclic behavior during switching](https://forum.plexim.com/t/mmc-cyclic-behavior-during-switching/1287)
**Author:** [@mohammad\_qaza](https://forum.plexim.com/u/mohammad_qaza)\ **Replies:** 3\ **Last updated:** [November 17, 2023, 9:28am UTC](https://forum.plexim.com/t/mmc-cyclic-behavior-during-switching/1287 "2023-11-17T09:28:06Z")
Please I need some help, I’m trying to simulate a MMC with 5 cells per arm dual half bridge submodels. I get the Cyclic behavior during switching error, I have tried all solutions listed in forum and help guides no luck … --- ## [Cycling behavior during switching due to probing](https://forum.plexim.com/t/cycling-behavior-during-switching-due-to-probing/1219)
**Author:** [@Pablo](https://forum.plexim.com/u/Pablo)\ **Replies:** 7\ **Last updated:** [April 17, 2023, 6:00am UTC](https://forum.plexim.com/t/cycling-behavior-during-switching-due-to-probing/1219 "2023-04-17T06:00:14Z")
Hello, I have already solved a “Cyclic behavior during switching, Switches that bounced” error by detecting that a probe component was the cause, but I would want to understand right why it happened. The probe measured … --- ## [How to define plecs circuit (blockset) simulation params separately from the main model?](https://forum.plexim.com/t/how-to-define-plecs-circuit-blockset-simulation-params-separately-from-the-main-model/1047)
**Author:** [@kabhijit](https://forum.plexim.com/u/kabhijit)\ **Replies:** 1\ **Last updated:** [July 27, 2021, 10:17am UTC](https://forum.plexim.com/t/how-to-define-plecs-circuit-blockset-simulation-params-separately-from-the-main-model/1047 "2021-07-27T10:17:31Z")
As I understand, to get the best performance I need to simulate the plecs circuit in variable-step mode. However, it seems that I can only make global changes to the simulation setting via the Simulink Simulation Setting… --- ## [Discrete time simulation of electrical machine control system](https://forum.plexim.com/t/discrete-time-simulation-of-electrical-machine-control-system/858)
**Author:** [@Nardi](https://forum.plexim.com/u/Nardi)\ **Replies:** 6\ **Last updated:** [September 14, 2020, 2:46pm UTC](https://forum.plexim.com/t/discrete-time-simulation-of-electrical-machine-control-system/858 "2020-09-14T14:46:12Z")
Dear all, I am currently modellig a control structure for a synchronous machine. I’m using a discrete solver and every controller of mine is discretized and build according to the Tustin method. After starting the simul… --- ## [How to simulate non-linear components in discrete simulation mode?](https://forum.plexim.com/t/how-to-simulate-non-linear-components-in-discrete-simulation-mode/832)
**Author:** [@shichenseu](https://forum.plexim.com/u/shichenseu)\ **Replies:** 2\ **Last updated:** [August 10, 2020, 9:05pm UTC](https://forum.plexim.com/t/how-to-simulate-non-linear-components-in-discrete-simulation-mode/832 "2020-08-10T21:05:00Z")
I defined a component by myself and I found that I cannot simulate non-linear components in discrete mode,the error message is as follows: The ‘Discrete state-space’ method cannot be used with circuits that contain nonl… --- ## [How to resolve error with discrete step solver when the simulation is moved from one version to another?](https://forum.plexim.com/t/how-to-resolve-error-with-discrete-step-solver-when-the-simulation-is-moved-from-one-version-to-another/799)
**Author:** [@snehathakur](https://forum.plexim.com/u/snehathakur)\ **Replies:** 0\ **Last updated:** [July 15, 2020, 10:18pm UTC](https://forum.plexim.com/t/how-to-resolve-error-with-discrete-step-solver-when-the-simulation-is-moved-from-one-version-to-another/799 "2020-07-15T22:18:16Z")
Hi I am using Plecs blockset (4.3.6) with Matlab 2019b. The model works fine both in variable-step solver and discrete step solver. However, when I export the model from Matlab 2019b to Matlab 2017b with Plecs blockset… --- ## [Problem with step fixed-variable](https://forum.plexim.com/t/problem-with-step-fixed-variable/787)
**Author:** [@Matias\_L](https://forum.plexim.com/u/Matias_L)\ **Replies:** 1\ **Last updated:** [June 24, 2020, 10:34am UTC](https://forum.plexim.com/t/problem-with-step-fixed-variable/787 "2020-06-24T10:34:36Z")
Hi everyone. I’m i’m having a problem with my simulation, at this point, i was using Fixed-step with 1e-8 step size to make my simulations, but i have the following problem: If i change to variable-step, i get the cor… --- ## [What is 'Variable-step discrete task'?](https://forum.plexim.com/t/what-is-variable-step-discrete-task/735)
**Author:** [@JonZ](https://forum.plexim.com/u/JonZ)\ **Replies:** 1\ **Last updated:** [January 22, 2020, 3:23pm UTC](https://forum.plexim.com/t/what-is-variable-step-discrete-task/735 "2020-01-22T15:23:01Z")
I am playing with fixed step solver and trying to convert a variable-step simulation model into a fixed-step one. But I get error message saying ‘variable-step discrete task are not supported with a fixed-step solver’ w… --- ## [About step size](https://forum.plexim.com/t/about-step-size/611)
**Author:** [@yanshaofei333](https://forum.plexim.com/u/yanshaofei333)\ **Replies:** 1\ **Last updated:** [January 17, 2019, 1:54pm UTC](https://forum.plexim.com/t/about-step-size/611 "2019-01-17T13:54:31Z")
i build a model and run it in Plecs (discrete state with 1e-7 step size) it works quite well. the RT box hat a minimal sample time of 1 micro sec (1e-6), so i change the plecs parameter to 1e-6, but when i build the mo… --- ## [The simulation always stops with the compare unit](https://forum.plexim.com/t/the-simulation-always-stops-with-the-compare-unit/601)
**Author:** [@YuJin](https://forum.plexim.com/u/YuJin)\ **Replies:** 1\ **Last updated:** [December 18, 2018, 4:23am UTC](https://forum.plexim.com/t/the-simulation-always-stops-with-the-compare-unit/601 "2018-12-18T04:23:06Z")
I run the simulation model and it always remind me as Fig.I. When I change the setting according to the reminder as Fig.II the simulation still stuck there but no reminder shows anymore. --- ## [The variable step and fixed step are giving different output voltages](https://forum.plexim.com/t/the-variable-step-and-fixed-step-are-giving-different-output-voltages/600)
**Author:** [@archit](https://forum.plexim.com/u/archit)\ **Replies:** 3\ **Last updated:** [December 13, 2018, 3:04am UTC](https://forum.plexim.com/t/the-variable-step-and-fixed-step-are-giving-different-output-voltages/600 "2018-12-13T03:04:44Z")
I am trying to simulate a model which is attached here. Dead time given is 2us. So when I am using variable step with max step size as 1us, some output voltage is showing in scope while simulating with fixed step size of…