Simulation tool to calculate microprocessor power consumption?
No.  There are no tools that I know of.  And if there were, they would be mostly useless.  There are just too many factors to consider that any tool would be wildly inaccurate.  If you do this at the very early stages of project conception, when most of your software has yet to be written, then your estimates could be 10x or more off!

The best that you can do is look at the microcontroller datasheet and estimate your max power consumption.  You could get a little deeper into it by also estimating how much time the MCU will be in sleep mode and factor that into it.  Much beyond that and you will not get much more accurate even though you spend a lot more time trying to estimate things.  Software tools will not help you much in this regard, even if they existed.