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Current spikes when modeling MOSFET, body diode, Output capacitor separately in PLECS for a resonant converter

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Hi, I'm modeling a resonant converter in PLECS. So I'm modeling each switch using MOSFET, body diode, output capacitance as shown in the figure. When I run the simulations applying thermal models of the manufacturers (infenion, cree) for the MOSFET and body diode I get current spikes at the MOSFET as shown in the figure. 

The PLECS model given by ROhm is for a MOSFET+diode block and it also runs fine without any spikes. The spikes only occur when applying thermal models for MOSFET and body diode separately.

Any help to solve this issue will be much appreciated.

The currents shown in the figure are for the switch IMZ120R030M1H of infenion ( I've used 0.1mOhm resistor in series with the output capacitor for the purpose of the simulation. The other parameters of the switch were set as given in the data sheet. I tried changing the gate resistance value and it didn't solve the issue.


asked Jan 15 by Tharuka (17 points)
edited Jan 19 by Tharuka
Are you able to post your model files for someone to better analyze what is happening?
Thanks Kris, I have uploaded the simulation file now.
Do you have a set of files showing the model working as expected? The differences between using the MOSFET and Diode combined component and separate components is that with the combined you cannot define a different resistance (Rdon) for the body diode from the Ron value of the MOSFET, and there is no ability to include the forward voltage of the diode. I expect then if you set the Vf values for all body diodes to 0 in the problematic model the spikes may diminish, at least after any initial transient settles, but please check. By the way, are you aware of the extremely high inrush currents at simulation start?

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