To open The Sims 3's Cheat Console, press Control + Shift + C. Cheating will keep them from getting tired, hungry, or stressed out. Instead, you have to use other commands to allow your Sim to focus their effort. The Sims 3 doesn't actually offer cheats to raise skills directly.
The Sims 3 Skills Cheats How to Use the Cheat Console to Raise Skills Fast
