Help in the control of an active three-phase pfc rectifier (active front end)

Hi, I have a problem with the control of a three-phase pfc rectifier controlled by MOSFETs (half bridge for each abc branch). I have implemented the physical part, which is the part I show in the first image (I also upload the model in case you want to see the values I have used). When I simulate with the SVPWM control it is not able to control the current and it quickly gets very high values in the three-phase part. The three-phase voltage is obviously OK, but the DC bus voltage is wrong. At the end I attach a couple of pictures with the results.

The problem is that the control does not work properly. Control in the outer loop is DC voltage (800 V is the reference). As you can see iin the result, voltage go to zero and do not follow the reference.

I don't understand what is wrong in the model because I think the controllers are well implemented. Can someone please help me?

Plant of the model:

I also attach an image of how the control is implemented:

Results:

Thanks.

Answer 1

[Sayan]

Hi Carmelo,

I have updated the model and now it follows the reference DC voltage at the output. The modifications are as follows:

• Increased the "DC Link" capacitor value to 4800 uF from 1100uF to reduce the output ripples.
• Set the "Gate-control port" parameter of the "IGBT(Ideal,Switching)" block inside each switching subsystem to "Electrical". This is done to simulate the real behavior of the switch with gate driver.
• The output of the "Switch" block inside each subsystem is provided to a "Controlled Voltage Source" block with a resistor.

After making the above modification the ouput voltage waveform is shown in the following image

I am attaching the modified model herewith. Hope this helps in resolving the issue.