Single Phase bridge Rectifier - Inversion mode problem

I'm trying to create a bridge rectifier operating in inversion mode.

To operate in inversion mode it is my understand that a constant current source has to be used.

And that inversion mode is when the load (in my case the current source) sees a negative voltage across it but the constant current is maintained.

Also to be able to achieve this thyristors need to be fired between the 90 and 180 degree phase angle.

My AC source is set to 230V operating at a frequency of 50Hz.

I have set thyristor 1 and 2 to fire at 150 degrees and thyristor 3 and 4 to fire at 330 degrees. To my knowledge when this happens my load (DC current source) should have a negative voltage across it when measured with a volt meter. But my results do not show this.

Can anyone please help me with this problem? I've attached the simulink model I am currently using. All help greatly, greatly appreciated.

Answer 1

[Keerthana Chiruvolu]

Hi,

For maintaining continuous current you may try using a RLE load( DC Motor). You can also adjust the pulsewidth of the pulse generator used for gate signal.

I made slight changes to your model. Kindly refer to attachment, in case you are using MATLAB 2019b version. It might help you.

Refer the following links for further information:

https://www.mathworks.com/matlabcentral/answers/263744-single-phase-fully-controlled-thyristor-converter-simulation-using-simulink