You should always avoid planting trees directly under power lines. Planting off to one side of the power line is preferable. Whenever you consider adding a new tree to your property, you should always evaluate the site for your new tree, including overhead utilities. Other site considerations include if the soil is wet or dry, if the area is sunny or shady, and if there are any underground obstacles.
Trees that mature at a height less than the height of the power lines, usually under 25 feet tall, are best for this application. Take your site information with you to a reputable nursery and work with its staff to select your new tree.