Abstract : This article introduces the working principle and control method of frequency converter. Following the principle of combining theory and practice, the article makes a detailed comparison and analysis of the working principle and control method of frequency converter. Keywords : frequency converter, control method, working principle In recent years, with the development of power electronics technology, microelectronics technology and large-scale integrated circuits, the improvement of production process and the reduction of power semiconductor device price, frequency conversion speed regulation has been increasingly adopted in industry. How to select a high-performance frequency converter for industrial control is a common goal pursued by our professional technicians. The following is a discussion of the working principle and control method of frequency converter based on the author's practical experience: 1. Working principle of frequency converter We know that the synchronous speed expression of AC motor is: n=60f(1-s)/p (1) Where n——the speed of asynchronous motor; f——the frequency of asynchronous motor; s——motor slip; P——the number of pole pairs of motor. As can be seen from equation (1), the speed n is proportional to the frequency f. As long as the frequency f is changed, the speed of motor can be changed. When the frequency f changes in the range of 0～50Hz, the speed adjustment range of motor is very wide. A frequency converter regulates the speed of a motor by changing the frequency of its power supply; it is an ideal, high-efficiency, and high-performance speed control method. [b][align=center]For more details, please click: The Working Principle and Control Method of Frequency Converters[/align][/b]