Could somebody please explain how I could use a single-phase transformer to conect a full bridge inverter output in series with the neutral of a three-phase transformer?

I am attempting to simulate a inverter-based current injector, that injects current into the neutral of a three-phase power transformer during fault conditions. Currently, I can get the toy network and the inverter to operate separately, but when I connect them with the transformer, there are no longer any signals shown on any of my scope plots. This makes it difficult to actually tune my controller, and optimise its behaviour.

COuld somebody please provide some insight as to what might be going wrong? The issue is not the control system itself, as no plots show when I connect the inverter to the transformer neutral via the transformer, without any control connected. I am guessing that there is something that doesn't like connecting a linear transformer to a power electronics output?

Unfortunately, I need to connect the inverter to the transformer neutral via a transformer, as this is how the physical device I am simulating operates. I cant use an ideal current source or anything.

I am usng Simscape electrical as well.

I must first run the GFN_Sim.m file to load variable values into the base workspace, which are then accessed by the simulink file.

Any help is greatly appreciated.

Cheers

Answer 1

[Joel Van Sickel]

Hello William,

There are two paths forward that I found in my look over this:

1: add some resistance to the distributed line parameters

2: do the following to switch to a variable step solver

Change power gui to variable step solver, and allow ideal switching.

Go to standard solver settings, and choose ode23tb, and change initial time step to auto.

Regards,

Joel

[William Taylor]

Hi Joel,

Problem solved. Thank you very much. Forgot to mention that I had been getting warnings about singular matrices. Would make sense that these were caused by the lack of resistance in the transmission line blocks.

Cheers,

Will