Abstract: This paper introduces the development, basic structure, speed control principle, and types of frequency converters. Based on a discussion of the mechanical characteristics of centrifugal pumps, it proposes the application and effects of frequency converters in energy saving. Keywords : Frequency converter, principle, type, pump, application effect I. Overview of Frequency Converter Technology Development DC motor drives and AC motor drives originated in the 19th century, with a history of over 100 years, and have become the main driving devices for power machinery. However, due to technological reasons, for a long time, AC motors were used in constant-speed drive systems, which accounted for about 80% of the entire electric drive system, while DC motors were mainly used in drive systems requiring speed control. Therefore, in industrial production, the most commonly used electric drive systems requiring speed control, such as fans and pumps, had to use baffles and valves to regulate wind speed and flow. Until the second oil crisis in the 1970s, people fully recognized the importance of energy saving and further emphasized and strengthened the research and development of AC speed control technology. With the development of power electronics technology during the same period, frequency converter technology, as the center of AC speed control systems, also developed significantly and gradually entered the practical application stage. Later, with the development of power electronics, microelectronics, and control theory, the performance of power semiconductor devices and microprocessors continued to improve, and inverter drive technology also saw significant development. With the application of various complex control technologies in inverter technology, the performance of inverters has been continuously improved, and their application range has become increasingly wider. Currently, inverters are not only widely used in traditional electric drive systems, but have also expanded to almost all areas of industrial production. [b][align=center]For more details, please click: Inverter Technology and its Energy-Saving Effect in Centrifugal Pumps[/align][/b]