I have attached my raspberry pi to a tv and it is powered via the tv's usb port. The problem is that the raspberry pi shuts off a few minutes after it starts up. I am fairly certain that this is a power issue because I have tried powering the pi via an outlet power connection and there are no problems. I was wondering if there are any settings I can change on the pi so that there are none of these power problems when I am getting power from the tv's usb port.
There's really no settings on the pi that would change how well that works. My guess is the TV port puts out the bare minimum power it needs to interface with whatever the specified receive is. Often times, USB ports on TV's aren't for anything more than a diagnostic tool or flash drive with some pictures on it.
My recommendation would be to plug the Pi into an outlet.
You can find out more about RPi power requirements here.
The important thing to note is that the RPi rev. A needs at least 500mA, and the rev. B 700mA, whereas many power adapters and USB ports provide 500mA max. Depending on your usage, you may use as much as 1500mA with a rev. B.
Thus, you should seek a power adapter that can provide at least 1000mA, and preferably more.
raspberry pi needs 700 mA
USB on the host device (TV) can supply 500 mA (max)
however when you use your raspberry pi to task which don't require much power TV is enough but don't be surprised when raspberry pi reboots when you hotplug wifi dongle
and yes, my TV supplies enough power for raspberry pi to work reliable (without any additional power-demanding HW attached)