SCR firing control

PLECS
1

Based on the demo, I build the attached module to check the basic function of a SCR rectifier circuit which has a 180 degree conduction range.

it seems the drive signals are OK, but the output DC link voltage is not in the right way.

please help me on this topic, it should be a basic using of the library model, but i did not find it yet.

scr control.plecs (83.6 KB)

2

A few quick comments on your model:

  • Start simple: use the regular Thyristor block from the PLECS demo model library and ensure your control is working before proceeding with the Thyristor with Reverse Recovery. Part of the issue is certainly the parameters you have entered for the more advanced Thyristor model.
  • Use the variable-step solver instead of the fixed-step solver.
  • Your PLL voltage input is non-sinusoidal as you’re capturing the voltage between the two inductors. This interferes with the PLL, were you can see the frequency output not being stable. You can use the AC source voltage directly for a more stable voltage measurement. Of course the model needs to be representative of your actual system, so if that’s not the case then you need to design a PLL which can handle the voltage waveforms you’re measuring.
1 Like
3

thank you, Bryan.

I will check later.