While not exactly "infinite power," this official developer shortcut allows you to instantly end the night, rendering power management irrelevant.
If you do not want to grind through the difficult nights to unlock the official cheat menu, you can manually unlock it by altering your save file. Because FNAF 1 saves its data in simple text files, you can edit your progress using Notepad. Step-by-Step Save File Modification fnaf 1 infinite power pc