I run a Half Court Press/2-3 Zone and for 2 years in a row ive had very high foul numbers per game. Id say about 30 per game almost every game. What in the engine causes this and what can I do to change it? Other than get guys with higher defense 

Why would you say other than get guys with better defense?  Because that would solve your problems.  Your defense and athleticism need to be much better.  There is no way to say this without sounding mean, but your team is just really bad.  I don't like any of your players.  
My advice to you is, read aejones guide and/or get a mentor.
Good Luck.

But now just to answer your original question.  If your only goal is to foul less, 1, stop pressing and only play zone. 2. play slow down.  It won't help you win, but it will lower the total number of fouls by a little.

You have low athleticism, defense and press iq. If you try to run a press without those three things, you will foul allot and there isn't much you can do about it other than getting yourself more athletic defenders and practicing the defense. Dedicate your next drafting class to speed, athleticism and defense.

You need to recruit people who are going to have a minimum final Defense Rating of at least 50.  ATH is also very important to overall Defense.

If you look at he DEF and ATH ratings of the best teams in your conference or the world, you should be able to see a good target range for overall team DEF and ATH.

But, if you want to win and if you want to press, you have to have good ATH and DEF.  Read the Winning at D2/D3 thread.  Did I say DEF and ATH enough?

Also .. the more Negative Defensive Positioning is, the more fouls you will have.  So, a -3, -4, -5 setting on position will cause many fouls.