Abstract : This paper describes the hazards of harmonics generated by frequency converters to the power supply system and proposes mitigation measures. Keywords : Frequency converter; Harmonics; Hazard mitigation I. Introduction In the field of industrial speed control and transmission, frequency converter speed control has many advantages compared with traditional mechanical speed control, and therefore its application is very widespread. However, due to the switching characteristics of the inverter circuit of the frequency converter, it forms a typical nonlinear load on its power supply. Frequency converters often operate simultaneously with other equipment in the field, such as computers and sensors, which are often installed very close together, potentially causing mutual interference. Therefore, power electronic devices, represented by frequency converters, are one of the most significant sources of harmonics in the public power grid, and they have a significant impact on the power quality of the power system. II. The Harmonic Generation Process The fundamental cause of harmonic generation is due to the nonlinear load. As mentioned in the introduction, the frequency converter forms a typical nonlinear load on the power supply. Therefore, when current flows through the frequency converter, it is not linearly related to the applied voltage, forming a non-sinusoidal current, thus generating harmonics, as shown in the figure below. Harmonic frequencies are integer multiples of the fundamental frequency. According to the Fourier analysis principle, any repeating waveform can be decomposed into sinusoidal components containing the fundamental frequency and a series of harmonics that are multiples of the fundamental frequency. Harmonics are sinusoidal waves, each with a different frequency, amplitude, and phase angle. Harmonics can be classified as even-order or odd-order. In a balanced single-phase system, due to symmetry, even-order harmonics are eliminated, leaving only odd-order harmonics. Therefore, odd-order harmonics cause more and greater harm than even-order harmonics. [b][align=center]For more details, please click: The Hazards and Treatment of Inverter Harmonics[/align][/b]