SMPS output filter loading issues

Hi Everyone. I am designing a 400W SMPS design[Max voltage : 200V Max Amp : 2A]. One completion of the design I tried to test it by connecting a 100 ohm 200W load to it. I made sure output voltage be set at 100V and over current protection at 3A. When I did turn it on, it drew only 100mA from the source and output voltage was only 36V. I guess SMPS could not source the current for the required load.

To debug I connected the load directly to the secondary of the isolation transformer bypassing rest of the circuit in the secondary and it was drawing 1.6A.[ Output voltage : 160V]
Then I connected it to the secondary high frequency rectifier diode and it was able to source around 1.6A bypassing the filter circuit. [Output voltage : 160V].
Then when I connected secondary circuit to the filter circuit, again the SMPS drew only 100mA from the source. I guess the filter consisting of the L = 750uH (T27 core) and cap = 220uF is the problem. I tried removing the load and then the open circuit output voltage was 100V.
Source could not see the resistive load and hence no current is flowing through it. Can you help me out with the filter design to make the SMPS work.

You should show at least a block diagram, preferably a detail schematic. The only reason I can imagine why the output filter is causing a SMPS shut down is that the 750 µH inductor is the only output filter of a buck converter and already saturated at low output currents due to wrong design.

Sorry. Mistake is on my path. I have included simplified block diagram below.
**broken link removed**

sorry cant see it....when you say LC filter do you mean the output inductor of say a full bridge converter, and the cap you refer to is the output cap bank, or are you referring to a post filter?

renga92 said:

**broken link removed**

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Hi Treez and everyone. Here is the reattached image.

something is wrong with your SMPS, likely noise getting into the control...

Hi. I am now making Inductor saturation current measurement circuit from online to check if it is problem or not. If it is not the case, then control might be the problem. Without loading [light load of 15K ohm], the output voltage is at the set voltage and it is constant. That means the feedback should be working, if I am wrong please correct me ?

I got a lot of different inductor values and current rating, tried with them only to see the input current increase from 100mA to 250mA. Is there anything revealing about the problem ? When I got 250mA, inductance values I tested with include 560uH, 1mH, 680uH and 1.5mH.