一、概述目前国内外研制的各种SCR-D自动调速系统广泛采用结构合理、性能优良的双闭环控制系统。我所自七九年以来,在光纤成缆机、螺旋挤出机以及双层挤出机中都采用了这种控制方案,并取得了很好的效果。所谓双闭环系统,就是在通常的速度闭环内部,再套置一个电流闭环。这种系统的简化原理图如图1所示。 I. Overview At present, a variety of SCR-D automatic speed control system developed at home and abroad widely adopt double closed-loop control system with reasonable structure and excellent performance. I have been using this control scheme in fiber optic cable machines, screw extruders and two-layer extruders since 1979, and achieved very good results. The so-called double closed-loop system, that is, within the usual closed-loop speed, and then set a current loop. A simplified schematic of this system is shown in Figure 1.