## [Qucs-help] Simulation of "power electronics" circuits and no convergence

 [Qucs-help] Simulation of "power electronics" circuits and no convergence From: Charles Joubert - 2007-04-25 08:08:27 Attachments: rectifier_1D.sch     Diode.sch ``` Hi all, I am trying to use qucs to simulate power electronics circuits with very simplified models of "switches" (i.e. : diodes, thyristors, IGBTs, MOSFETs...). Basically, in these models, the switch is either "on" (constant resistance of low value) or "off" (constant resistance of high value). The state of the component depends on its type and possibly external conditions. For example for a diode : If Iak>0 => diode on If Iak<0 => diode off This way of simulating components is classic in power electronics. It is used for example in softwares like PSIM (http://www.powersimtech.com/download.html). I tried to simulate a very simple rectifier. The "diode" is built with a relay (files included). The problem is that I get this message : WARNING: delta rejected at t = 1.001e-02, h = 1.000e-09 (no convergence) Is there a way to work around this ? Thanks ! Charles JOUBERT ```

 [Qucs-help] Simulation of "power electronics" circuits and no convergence From: Charles Joubert - 2007-04-25 08:08:27 Attachments: rectifier_1D.sch     Diode.sch ``` Hi all, I am trying to use qucs to simulate power electronics circuits with very simplified models of "switches" (i.e. : diodes, thyristors, IGBTs, MOSFETs...). Basically, in these models, the switch is either "on" (constant resistance of low value) or "off" (constant resistance of high value). The state of the component depends on its type and possibly external conditions. For example for a diode : If Iak>0 => diode on If Iak<0 => diode off This way of simulating components is classic in power electronics. It is used for example in softwares like PSIM (http://www.powersimtech.com/download.html). I tried to simulate a very simple rectifier. The "diode" is built with a relay (files included). The problem is that I get this message : WARNING: delta rejected at t = 1.001e-02, h = 1.000e-09 (no convergence) Is there a way to work around this ? Thanks ! Charles JOUBERT ```
 Re: [Qucs-help] Simulation of "power electronics" circuits and no convergence From: Stefan Jahn - 2007-04-25 11:25:27 ```Am Mi, 25.04.2007, 10:06, schrieb Charles Joubert: > Hi all, Hello Charles, > I am trying to use qucs to simulate power electronics circuits with > very simplified models of "switches" (i.e. : diodes, thyristors, IGBTs, > MOSFETs...). Basically, in these models, the switch is either "on" > (constant resistance of low value) or "off" (constant resistance of high > value). The state of the component depends on its type and possibly > external conditions. > For example for a diode : > If Iak>0 => diode on > If Iak<0 => diode off > > This way of simulating components is classic in power electronics. It > is used for example in softwares like PSIM > (http://www.powersimtech.com/download.html). > > I tried to simulate a very simple rectifier. The "diode" is built with > a relay (files included). > > The problem is that I get this message : > WARNING: delta rejected at t = 1.001e-02, h = 1.000e-09 (no convergence) > > Is there a way to work around this ? Thanks ! Your diode model appears to be wrong. The non-grounded input terminal of the relay has to be connected with the A-port. Then it works fine. Cheers, Stefan. ```