Abstract : This paper discusses radiation, conduction, and inductive coupling as the main propagation paths of electromagnetic interference (EMI) and the main factors interfering with frequency converters. Corresponding anti-interference measures are proposed for these propagation paths. Keywords : Frequency converter, electromagnetic interference analysis, solution method. Interference with frequency converters is essentially electromagnetic interference. This interference is not limited to frequency converters; high-voltage transmission lines, transformers, welding machines, power switch operations, high-frequency oscillation circuits, gas discharge lamps, power tool commutators, automotive ignition systems, and switching power supplies are all interference sources. The only difference lies in the intensity and propagation path of the interference generated by different devices. 1 Interference Paths Radiation, conduction, and inductive coupling are the three main propagation paths of EMI. 1.1 Radiation Radiation refers to the outward emission of electromagnetic interference through space. Its intensity depends on the current intensity and emission frequency of the interference source. Most frequency converters use PWM technology in their inverter bridges. When the expected and repetitive switching patterns are generated according to the given frequency and amplitude commands, the frequency converter output carries high-order harmonic groups corresponding to the switching frequency. The radiated interference caused by high carrier frequencies and high-speed switching of field-controlled switching devices is more prominent. [b][align=center]For details, please click: Analysis and Solutions for Inverter Interference Immunity[/align][/b]