直流电动机外文文献.doc

外文文献 1. INTRODUCTION Electric Drive Technology Development 1.1 Current Situation 30 Over the years, the DC motor drive has undergone significant changes. First of all, replacing a rectifier, thyristor rectifier device to replace the conventional long-standing group of DC motors and generators of mercury rectifier DC electric drive device to complete a big leap forward. At the same time, control circuit has achieved a high level of integration and miniaturization, high reliability and low cost. More than technology, so that DC Speed Control System increase performance, expanding the scope of application. DC drive technology development to mature, and perfect, serialization, standardization, in the reversible PWM, high-precision field of electrical transmission is still hard to replace. 1.2. Computer control and status of the development of motor Relatively simple computer control of the motor, as long as the use of microcomputer control relay or electronic switching elements so that the circuit open or off it. In a variety of machine tool equipment and production lines, the now commonly used with the programmable computer controller, in accordance with the laws of certain types of motor control action. For the complex motor control, then use computer control motor voltage, current, torque, speed, angle, etc., so that motor in accordance with the instructions given accurate work. Through computer control, motor performance could greatly improve. 2. Speed and current dual closed-loop speed control system of the two regulator cascade connection for the outer speed feedback loop, current loop for the inner ring. The speed regulator output current is given, the output amplitude is limited to the maximum current value. Adjust the limit of small amplitude or current-feedback coefficient can be adjusted easily to change the maximum current. In effect, the braking process, the speed regulator quickly into saturation, the output amplitude limit for the current loop to pro