电能表转盘转动30r，电路消耗的电能为：W=30× 1 3000 kW?h=0.01kW?h=3.6×104J，灯泡单独工作时间；t=3min=3×60s=180s，∵P= W t ，∴灯泡的实际功率：P= W t = 3.6×104J 180s =200W．故答案为：200．
