You can only keep VFT's going with artificial light for awhile. But it weakens them, over time. They really need direct sunlight. Dormancy needs to be cold, lower photoperiod, and dry.

VFTs can be grown successfully indoors. I've done it and so have many other people. You will need 40w T12 or 15w T5 fluorescent to do it. You must have the lights very close (1-2 inches) to the plant so install your lights with chains so you can adjust the height. You can also use MH or HPS lights but they are expensive.

VFTs are much healthier if grown outside in full sun.