Why is my state refund greater than the estimated payments that I made?

It's possible, but it seems more likely that you're getting a credit of some sort on your state return.  Please provide more information:

• What state return are you working on?
• What's the amount of the refund that's greater than what you're anticipating?
• If you go through your state return, you should come to a screen related to taxes and credits.  Do you see anything unusual populated there?

Do you get retirement and a 1099R?  Check box 14 for state withholding.