19世纪80年代工业上传动用的电动机一直被直流电机垄断，19世纪末出现

In the 1980s, the motor used for transmission in the industry has been monopolized by DC motors. At the end of the 19th century, a three-phase power supply and a simple and durable AC squirrel cage motor appeared. AC motors replaced DC motor transmissions in the field of speed regulation. With the continuous development of production, if you want to achieve the speed regulation of electric devices, you must also have continuous stability and good transient performance. Since the 1950s, foreign countries have begun to pay attention to AC motor speed regulation. Most small and medium-sized induction motors use thyristor voltage regulation and large and medium-sized wound induction motors use thyristor static electrical cascade speed regulation systems. With the development of electronics and electronic technology, the adoption of semiconductor variable speed control system has been realized. After the 1970s, the development of large-scale integrated circuits and computer control technology and the application of modern control theory have created for the development of AC motor drive systems. The favorable conditions are promoted, and the rapid development of the AC motor speed control system is promoted.

In the 1880s, the electric motor used by industrial upload has been monopolized by DC motor, at the end of the 19th century there was a three-phase power supply and simple structure and durable AC rat cage motor, AC motor in the field of speed control instead of DC motor transmission. With the continuous development of production, it is necessary to achieve the speed control requirements of electric devices with continuous stability and good transient performance. From the 50's, foreign countries began to pay attention to AC motor speed control, small and medium-sized induction motors more use of the thyristor pressure control speed and large and medium-sized winding induction motor using the thyristor static electrical string speed control system. With the development of electronics and electronic technology, the use of semiconductor variable-flow speed control system can be realized, after the 70's large-scale integrated circuit and computer control technology development and the application of modern control theory, for the development of AC motor drag system has created favorable conditions, and promoted the rapid development of AC motor speed control system.

In the 1980s, the motor used in industry was monopolized by DC motor. At the end of the 19th century, there appeared three-phase power supply and simple and durable AC squirrel cage motor, which replaced DC motor drive in the field of speed regulation. With the continuous development of production, it is necessary to have continuous stability and good transient performance to realize the speed regulation requirements of electric devices. Since the 1950s, foreign countries began to pay attention to the speed regulation of AC motor, and most of the small and medium-sized induction motors adopt thyristor voltage regulation and speed regulation, and large and medium-sized wound induction motors adopt thyristor static electrical cascade speed regulation system. With the development of electronics and electronic technology, the adoption of semiconductor variable current speed regulation system can be realized. After the 1970s, the development of large-scale integrated circuit and computer control technology and the application of modern control theory have created favorable conditions for the development of AC motor drive system and promoted the rapid development of AC motor speed regulation system.