Diode Model for Converter Simulation in LTSpice

Thread Starter

DannyInduction

Joined Jan 17, 2023
3
Hey there!
For my master thesis I am simulating a converter for induction heating. The power of the inductor is at 165kW. The problem is that I do not find a good diode model. As you can see in the simulation I made my own model DD600, based on the diode model 1N4148. So know I want to change the values of the Diode. I had tried to put the forward voltage in but then the simulation is not running anymore. And when I set Rs under 0.1ohm the simulation is also not running. Right now I have power losses in the bridge rectifier of 40kW. I don't know how to make it right.

I hope you guys can help me!!
 

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Thread Starter

DannyInduction

Joined Jan 17, 2023
3
Hi ericgibbs! Thanks for the fast answer!
My problem was the power loss in the bridge rectifier, but I found the answer. I did forget to set the Ron value.

But now I have another problem. In my thesis I compare two different converter types. A compensated one and a not compensated one. The none compensated Is this above and it is running but the compensated converter is doing weird stuff. Can you please look over it?
 

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ericgibbs

Joined Jan 29, 2010
18,766
hi Danny,
This sim is just a quick check of the rectification and loading, Diode set as Ron =0.0001
I will download your post #3 asc file and run it.
E
EG57_ 471.png
 

ericgibbs

Joined Jan 29, 2010
18,766
Hi
Your simulation has rapidly changing signals with rapidly changing derivatives.
The presence of a pseudo-transient analysis is indicative of difficulty in establishing a DC operating point.
Basically, LTSpice cannot compute solutions for a very small-time, hence the time step has to be increased.

It is a limitation within LTSpice.

E
 
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