Troubleshooting my IGBT: Vge not Meeting Design Requirement

[onceinalifetim]

currently i need to turn on my IGBT. i measured Vge, it shown 8.25V, but my design requirement of Vge is 15V.
i did some research, do i need to add in parasitic capacitances to my IGBT??

 

[Windadct]

Sorry this post is not too clear. You already have a circuit and it is supplying gate voltage of 8.75V - and then you mention design requirement - from where? The IGBT Datasheet?
Parasitic Capacitance - ? -- the root word is parasite -- not something you want to add, it may be that you need to account for the parasitic, but usually in IGBTs we have problems with parasitic inductances. The Gate structure does create a capacitance, so you need to estimate the drivers current / power based on this and the Fsw.