Abstract : This paper introduces a comprehensive application system of microcontroller and frequency converter. The system uses an 8098 microcontroller and a Fuji frequency converter as the main control components. It can be used to develop and study the functions of the frequency converter independently, and can also form a microcomputer-controlled AC variable frequency closed-loop speed regulation system, which is suitable for experimental teaching and engineering applications in special environments. Keywords: frequency converter; microcontroller; closed-loop speed regulation system Currently, AC frequency converters are popular among users due to their stable and reliable performance, high control accuracy, small size, and ease of use. At the same time, the increasing maturity and improvement of microcontroller technology gives it a broad prospect in the field of engineering technology applications. Therefore, organically combining the two to form an application system is of great significance for their promotion and use. 1 System Functions and Features 1) Multi-functionality. This system can directly conduct basic frequency converter function experiments to complete direct digital control, analog control, or terminal switch control of the frequency converter, and can also form an AC variable frequency speed single closed-loop speed regulation system controlled by an 8098 microcontroller to realize digital closed-loop control. 2) Diverse control forms. The system retains both traditional analog signal control and a direct digital control mode. 3) Intuitive display: In addition to voltmeters and ammeters, the system is equipped with two digital displays. During system operation, one display shows the given speed, and the other shows the actual motor speed. 4) Comprehensive protection functions: The system includes protection circuits not only in the main circuit but also in critical parts of the control circuit, preventing damage to the equipment due to improper use. [b][align=center]For more details, please click: Integrated Application of Microcontroller and Variable Frequency Speed ​​Control Technology[/align][/b]