Abstract: The design uses thyristors, diodes and other devices designs a speed, current double-loop SCR DC converter system. The system sets up the current detecting aspect, the current regulator ACR and the speed detecting link, speed regulator ASR, composes the current central and the speed central, the former through the feedback of the current components to level off the current, the latter through the feedback of speed detecting device to maintain the speed stably and finally eliminates the deviation of speed bias.，thus allowing the system to the purpose of regulating the current and speed. when the system starts, the speed outer ring saturats non-functional, the current inner ring plays a major role to regulate the starting current to maintain the maximum so that the speed linear change, to reach a given value; when it operates steadily, the speed negative feedback from the outer ring plays a major role ,to let the speed changes with the given speed voltage , at the same time the current inner ring regulates the armature current of motor adjustment to balance the load current. when operating steadily ,the system without static error, current overshoot volume is less than , when starting to the rated speed with no load ,the speed overshoot volume is less than .
Keywords: Double-loop, thyristors, the speed regulator, the current regulator
