Abstract : This paper mainly introduces the sources and propagation paths of interference in frequency converter application systems, proposes practical solutions for anti-interference, and elaborates on specific measures to suppress interference in the design and installation of frequency converter application systems. Keywords: frequency converter; anti-interference; suppression 1 Introduction Frequency converter speed regulation technology is a high-tech technology integrating automatic control, microelectronics, power electronics, communication and other technologies. With its excellent speed regulation and energy-saving performance, it has been widely used in various industries. With the rapid development of science and technology, frequency converters, with their characteristics of power saving, energy efficiency, reliability and high efficiency, have been widely used in various fields of industrial control. However, during operation, the power supply and electrical equipment on site will affect the frequency converter, and the high-order harmonics generated by the frequency converter during operation will also interfere with the operation of surrounding equipment. The following mainly discusses the interference of frequency converters and its suppression methods. [b]2 Main Electromagnetic Interference Sources and Pathways of Variable Frequency Speed ​​Regulation Systems 2.1 Main Electromagnetic Interference Sources[/b] Electromagnetic interference, also known as electromagnetic disturbance (EMI), is electromagnetic interference caused by external noise and unwanted signals during reception, usually propagated through circuit conduction and in the form of fields. The rectifier bridge of a frequency converter is a non-linear load for the power grid, and the harmonics it generates can cause harmonic interference to other electronic and electrical equipment on the same grid. Furthermore, most frequency converter inverters use PWM technology, which generates significant coupling noise when operating in switching mode and performing high-speed switching. Therefore, the frequency converter is an electromagnetic interference source for other electronic and electrical equipment within the system. On the other hand, harmonic interference from the power grid mainly affects the frequency converter through its power supply. If the power supply to the frequency converter is subjected to interference from a polluted AC power grid and is not addressed, the grid noise will interfere with the frequency converter through the power supply circuit. [b][align=center]For more details, please click: Solutions for Frequency Converter Anti-interference Technology[/align][/b]