So far the best way I have found to do it was to run to either side of the platform and use repeated lightning to fry the Tie's as they swoop around the pillar on the side your on. You can get about 4 ties back to back before you have to wait to recharge your force.
Then start pulling down the SD. I dont know if the error is the same on the PS3, but on the 360 version sometimes the analog sticks on the screen appear green even though it wont let you pull the SD down yet. What that means is usually you have to lift the nose of the SD up a bit before you get the "Pull" arrow markers on the screen. keep pulling even after the tie's start shooting at you and don't stop until they have your health nearly out. Then just repeat the process by running to one side of the platform and blowing up the ties.