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、产品质量的要求不断提高和产量的增长,使得越来越多的生产机械要求能实现自动调速.因此,对电机调速的研究有着积极的意义.对可调速的电气传动系统,可分为直流调速和交流调速.直流电动机具有优良的调速特性,调速平滑、方便,易于在大范围内平滑调速,过载能力大,能承受频繁的冲击负载,可实现频繁的无级快速起制动和反转,能满足生产过程自动化系统中各种不同的特殊运行要求,至今在金属切削机床、造纸机等需要高性能可控电力拖动的领域仍有广泛的应用.近年来交流调速系统发展很快,然而直流控制系统毕竟在理论上和在时间上都比较成熟,而且从反馈闭环控制的角度来看,它又是交流系统的基础,长期以来,由于直流调速系统的性能指标优于交流调速系统.因此,直流调速系统一直在调速系统领域内占重要位置.

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.