專業英語作文關於電路

篇一：電氣專業文章英漢對比

With the rapid development of power electronics, computer science and control theory, a revolution happened in motor drives. Actually, AC drives are the

mainstream of motor drives. Permanent magnet synchronous motors (PMSMs) have been widely used as AC drives over the last two decades due to their high efficiency, high power density and no dc field winding in the rotor. It is well known motion control of PMSM requires accurate position and velocity signals to realize field orientation. In conventional motion control systems, optical encoders or

electromagnetic resolvers are used for this purpose. However, these additional sensors increase the costs of the system and decrease the reliability. With this background, sensorless operation is fast becoming a requirement, and the

elimination of position and velocity sensors has been an attractive prospect.