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.