说明：  用Simulink中的SimPowersystem完成一个转速、电流双闭环直流调速系统的设计与仿真。采用三相桥式整流，平波电抗器Lp的大小可根据根据仿真调整。给出电机在空载启动，以及在2.5S后加额定负载时转速、电流、电压的变化曲线，并结合调速理论分析这些曲线。
(With Simulink in SimPowersystem complete a speed, current double-loop DC speed design and simulation system. Three-phase bridge rectifier, smoothing reactors Lp size can be adjusted according to the simulation. Start the motor load is given, and the speed curve when the rated load after 2.5S, current, voltage, speed and theoretical analysis of these binding curves.)