I am currently working on a boost converter.
the current waveform i am getting is this(of inductor).
It has no similarity with theoritical waveform.
My doubt is the core is getting saturated.
can anyone have an idea what could be the reason??
Need to look at the schematic. It's not possible to distinguish core saturation and possible switch current limiting by only looking at the waveform. Also the current polarity should be clarified. If it's a DC current probe, we won't expect saturation near zero current.
The switch node looks okay (though it looks like less than 100V on the output). I suspect there's something wrong with the current probe itself. Are you sure it has enough bandwidth?
I changed the inductor. now i am getting correct waveform. thank you guys.
so the problem was core saturation
And one more problem i am facing is about voltage spikes.
across mosfet working voltage is 110v but i am getting around 300V voltage spikes. is it okey to leave it as it is or i have to go for a snubber?
the mosfet is rated 650v.
Here is pcb layout document which you must satisfy b4 looking into snubbers.
If you can pass emc though, and you dont overvoltage anything with the ringing, then doesnt matter about ringing too much, just leave it.
There was definitely something other than core saturation happening. Saturation can't cause the lagging waveforms you showed.
And one more problem i am facing is about voltage spikes.
across mosfet working voltage is 110v but i am getting around 300V voltage spikes. is it okey to leave it as it is or i have to go for a snubber?
the mosfet is rated 650v.
The FET should be okay, though you should also make sure the negative spikes aren't going to exceed the voltage rating of the diode. But even if the power components can withstand the spikes, they will likely cause large amounts of emi in the rest of the system, so they should be tamed. Try optimizing your layout to reduce parasitic inductance, and then add a snubber.