Abstract : With the widespread application of frequency converters, fault repair issues have become increasingly prominent. Therefore, mastering some fault analysis and repair methods for frequency converters is essential for on-site maintenance and operation personnel. This article takes the SENLAN BT40 IGBT digital frequency converter as an example, analyzes the structure and performance of each module through system analysis, and summarizes the "segmentation method" based on the author's many years of experience in the use and maintenance of frequency converters. This method has been applied in actual maintenance practice and has a positive effect on guiding on-site maintenance. The segmentation method can effectively narrow down the fault range and quickly locate the fault point, making it worthy of widespread application. Keywords : BT40 frequency converter, module analysis, segmentation method. Frequency converters will encounter various faults during on-site operation. The causes of these faults vary greatly; some are obvious, while others are quite hidden. Therefore, mastering some fault analysis and repair methods can achieve twice the result with half the effort in our work. The "segmentation method" is one such effective method. The so-called "segmentation method" refers to modularizing the components of a frequency converter based on its internal circuit structure and the different functions of each part. This minimizes on-site problems, making maintenance work more targeted and shortening repair time. We will take the SENLAN BT40IGBT digital frequency converter as an example for segmentation. The SENLAN BT40IGBT high-performance digital frequency converter is a universal AC-DC-AC frequency converter in terms of circuit structure. Based on the different functions and roles of its parts, it is "segmented" into four functional parts: "rectifier module," "inverter module," "system control and drive module," and "external interface circuit module" (as shown in Figure A). A brief introduction to the functions and roles of these four parts in the frequency converter is as follows: [b][align=center]For more details, please click: Segmentation Method and Maintenance of SENLAN BT40 IGBT High-Performance Digital Frequency Converter[/align][/b]