Wednesday, June 25, 2014

Restarting

Been a long time since I posted. Have been busy with building my hardware setup for my research and now they are almost working the way I want. With this done, I now will have to divert some of my time towards this project.

Spent the past week or so reading most of the code all over again. Another task has been portability to Python 3. Have to look into compatibility issues with respect to that. But before that to complete a tested power electronics library.

One of the problems with combining mesh analysis and nodal analysis was that if both are performed whenever an event occurs, freewheeling can be said to occur even when it is not meant to occur. For example, in a three-phase diode bridge rectifier fed by a source with a finite inductance, the turning off of a diode can be seen as cause for freewheeling of the inductor current and causing the other diode in the leg to freewheel.

So, my guess is there comes the need to distinguish between nonlinear element events -  a hard switched event or a soft switched event. A soft switched event is when a device (diode or switch) turns off when the current through it becomes negative. In that case, freewheeling should not happen. However, when a switch is turned off, and the current through it (irrespective of the magnitude) is broken, freewheeling needs to occur if there was an inductor in a branch connected to the node.

That is the immediate next step.