parasitic effect in power electronics

[srinivasan ramakrishnan]

when we connect the forward diode parasitic effect can be eliminated. parasitic effect is the internal capacitance of inductor proximity to capacitance..... diode also having internal capacitance then how it's eliminated the parasitic effect when the diode connected to forward to the inductor

 

[vimalkhanna]

Parasitic capacitance is generated by a linear current flow in adjacent windings of any inductor .To reduce this , increase the airgap between the winding coils .The diode (pn jn.)is a capacitance and stores charge in the poles P and N..
When both are coupled in kirchoffs mode ,they annul .However , you need to carefully choose the switching diode for the correct value of static parasitic value .
Ref. 1N4149 has static cap of 2pf.///1N5408 has 3.5pf and 1N4007 has excess of 7pf...These caps provide for propagation delay ,storage ,transient responses.