Bring broth to a boil in a medium saucepan; stir in bulgur and turn off heat. Cover and set aside for 25 minutes. Fluff with a fork and let cool completely. Stir in grapes, onion, mint, and orange. In a small bowl, whisk together oil, lemon juice, sugar, salt, ginger, cumin, and pepper. Pour over bulgur and toss well. Chill until ready to serve.