Problem with Power Converter Circuit

[madhu.b]

Hello,

I have problem with my power converter circuit. The circuit deliver the required result (i.e: Vin-30V, Iin-0.2A, Vout-8V, Iout-0.5A) in the simulations. When come to the hardware board (PCB) which needs to 1A and above input current in order to meet output power and efficiency same as I got in the simulations.
So, please could you tell me that why the hardware board (PCB) consuming more current in order to meet required results.
What is the reason??

 

[nitishn5]

Give circuit schematic.

 

[madhu.b]

Here you can see my circuit schematic...


https://obrazki.elektroda.pl/1024107400_1360936986.png

 

[mtwieg]

Is this some sort of resonant converter? If so it looks like it must operate at a very high frequency. Do you know that your components have high Q at such frequency?

 

[madhu.b]

Yes exactly I chosen according to my requirement.....

Again I have the other problem with my circuit. When I am running the circuit, the CV (constant voltage) mode is switching to the CC (constant current) mode. Thus, this may effect on my circuit results.

So, please could you tell me that what is the problem with the circuit.

 

[mtwieg]

It's not surprising that the simulation gives different results than reality. The simulation probably assumes not conduction losses in the passive components, and perfect gate drive for the FET.

You should at least try and verify that you're getting ZVS or ZCS when expected, so that your FET switching losses are low. Then you can start looking at conduction losses in the various inductors and transformers. It's likely that there's a great deal of loss there.

And you should probably aim for a much lower switching frequency range (like less than 1MHz), unless you're using some very fancy FETs.

 

[madhu.b]

Now I have other problem in my circuit....

I Swap the power supply pins which means I given the positive supply connected to the negative pin and negative supply connected to the positive pin...
I am not getting the proper results after given the negative voltage to the converter circuit(i.e: The circuit is not working properlly).
Do you think this may effect on the boad.

 

[mtwieg]

You mean you applied a negative DC voltage to the input of the converter? It's likely that doing so permanently damaged the circuitry, such a converter is only meant to work with one voltage polarity.