Hi Ubaid,

Estimating the conduction loss of a switch is pretty straightforward. You need to use "RI^2" expression for this, in which "R" is the MOSFET channel resistance and "I" is the rms current of the switch.

For the switching losses, if full ZVS happens for the switch, the turn-on losses due to the "discharging of the output capacitance though the channel of the device" is almost zero. Traditionally, this would considered as "zero turn-on switching losses". This has been assumed in the literature until recently. However, there is another mechanism that can causes switching losses even in the presence of full ZVS and that is :" charging and discharging of a MOSFET output capacitance is not free of losses ". In other words, even if we have a full ZVS for a switch, charging and discharging of the output capacitance of a switch during the ZVS process can cause some switch losses (this loss mechanism is specially very pronounced in SuperJunction MOSFETs). This is called "soft-switching losses due charging and discharging of MOSFET output capacitance" .This is what has been traditionally neglected in the literature when investigating the switching losses under ZVS conditions.

This is a great paper that talks about this soft-switching losses due to charging/discharging of output capacitance. I highly recommend reading it:

Article Accurate Transient Calorimetric Measurement of Soft-Switchin...

These two articles are also among the very first that identified this loss mechanism. I also recommend them:

https://ieeexplore.ieee.org/document/6803302

https://ieeexplore.ieee.org/document/7467880

Hope this helps. Good luck!