Boost+H-bridge problem

[xlxlyu]

dc to ac h bridge

i want get a 100V/1khz sin AC through 5V DC,
the first circuit is boost ,change 5V DC to 50V DC,
then H-bridge circuit change DC to AC,in SPWM control,

the simulation of single circuit is ok,but when i put those circuit simulate together,
the output wave is wrong , i don't know why ,needs help ,tks!!!

 

[yeechyan]

h-bridge booster

You need to have feedback here. Without the feedback the circuit won't be able to track the output and compensate for it.

 

[xlxlyu]

h-bridge boost

but how to add feedback,can u explain it

 

[yeechyan]

Do you have IEEE account? If yes you can try downloading this paper:
ieeexplore.ieee.org/iel4/7/8964/00395244.pdf
ieeexplore.ieee.org/iel5/10622/33557/01594121.pdf

You can also read this paper:
http://www.atmel.com/dyn/resources/prod_documents/doc4865.pdf

Added after 2 minutes:

Usually we can apply feedback from the output of the H-Bridge or from the load. Applying feedback directly from the output of the H-Bridge requires some filtering while applying feedback from the load can track the output signals without extra filtering but there are phase shift caused by the filter connecting the H-Bridge to the load.