Why do you take the effort to first add image to ms word and then compress it just one more time? Why not just upload as png image file?
Also I tried open the file with Open Office, but the image just looks terrible.
Go get FSIV, take screenshot (using fsiv) and save it as 256 color png image before upload to forum. That way you probably can make the same image less than 30kb.
Talking about the lower circuit (the three filters) I'll guess that first stage si to completely filter out the main frequency (50 hz).
Next stage makes a loop between opamp output (igbt's) and its positive terminal. But I'm not able to tell if this total sum results in a positive or negative backlink (google translate suggestion this word).