英语翻译随着时代的进步和科技的发展,电机调速系统在工农业生产、交通运输以及日常生活中起着越来越重要的作用,生产工艺、产品

As the era of progress and the development of science and technology, motor drive system in industrial and agricultural production, transportation and daily life plays a more and more important role, production technology, product quality constantly increasing demand and output growth, make more and more production machinery requirements to achieve automatic speed。 Therefore, the study of motor speed has a positive meaning。 For adjustable speed electric drive system, can be divided into dc speed control and communication speed。 Dc motivation has excellent speed characteristics, smooth, convenient, easy to speed on a large scale speed, smooth overload ability is big, can withstand the shock load, frequent can realize frequent stepless is fast start-stop and reverse, can satisfy the production process automation system in different kinds of special operation requirements in metal cutting machine, since such require high-performance controllable crispness field of electric drive are still widely used。 In recent years, the development of ac speed adjustment system of dc control system soon after, however in theory and in time are more mature, and closed loop control from feedback perspective, it is the basis of communication system, for a long time, because the performance index of dc speed control system better than exchange speed regulation system。 Therefore, dc speed control system has been governing system, which occupies an important position within the territory。